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Genetics
Genetics
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Genes
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Chromosomes
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Meiosis
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Transcription and gene expression
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Stages of Meiosis
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Inheritance
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Genetic Modification and Biotechnology
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DNA Structure and replication
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Genes
1
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Genetics
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1
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1
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how information can be transferred from parent to child
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3
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2
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2
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Genes are linked in groups
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1
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Each group corresponds to one of the types of chromosomes in a species
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2
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a fruit fly has four groups of linked genes and four types of chromosomes
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Alleles
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1
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3
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1
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3
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can be more than two alleles of a gene
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2
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Ex
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3
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1
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A gene that influences coat colour has three alleles
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2
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Ex
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3
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2
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Three alleles of the gene in humans that determines ABO blood
groups
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3
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3
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1
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adenine might be present at a particular position in the sequence in
one allele and cytosine at that position in another allele
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4
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4
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4
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new alleles are formed from other alleles by gene mutations
1
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1
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Mutations are random changes to the base sequence of a gene
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1
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1
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4
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1
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1
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4
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1
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1
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Has enough energy to cause chemical changes in DNA
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1
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1
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2
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Gamma rays, alpha particles from radioactive isotopes
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1
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1
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Chemical substances
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1
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1
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1
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4
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1
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2
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Ex
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4
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Most significant type of mutation is a base substitution
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2
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One base in the sequence of a gene is replaced by a different base
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3
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4
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1
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4
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2
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4
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2
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causes death of a cell in which mutation occurs

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1
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4
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4
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1
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5
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5
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A genome is the whole of the genetic information of an organism
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1
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Organism's genome is the entire base sequence of each of its DNA
molecules

2
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1
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1
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Most prokaryote there is one chromosome
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1
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consisting of circular DNA, containing all genes need for basic life
processes
2
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1
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DNA not associated with proteins, described as ""naked""
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Plasmids
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1
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2
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1
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2
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2
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2
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3
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2
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4
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2
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5
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2
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Copies of plasmids can be transferred from one cell to another

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2
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3
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2
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1
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2
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2
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3
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3
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Chromosomes are composed of DNA and protein
2
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1
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DNA is a single long linear DNA molecule
2
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1
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Associated with histone proteins
2
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Differences between chromosomes
2
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1
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4
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1
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4
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1
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centromere can be positioned anywhere
2
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2
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4
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1
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5
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5
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Homologous chromosomes carry the same sequence of genes but not
necessarily the same alleles of those genes
2
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1
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if two chromosomes hae the same sequence of genes they are
homologous
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1
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usually not identical to each other because the alleles are different

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2
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2
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6
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6
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Haploid nucleus has on chromosome of each type
2
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1
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Has one full set of chromosomes that are found in its species
2
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1
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Haploid nuclei in humans contain 23 chromosomes
2
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2
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6
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1
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7
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7
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Diploid nucleus has two chromosomes of each type
2
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1
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Has two full sets of chromosomes that are found in its species
2
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1
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Diploid nuclei in humans contain 46 chromosomes
2
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2
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7
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many animals and plants consist entirely of diploid cells
2
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Chromosome numbers
2
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1
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8
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Organisms with a different number of chromosomes are unlikely to be able
to interbreed

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2
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3
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9
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9
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Two chromosomes in humans that determine sex
2
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1
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X chromosome
2
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1
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1
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9
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1
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has a centromere near the middle
2
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1
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3
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9
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1
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all humans have X chromosome
2
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1
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Y chromosome
2
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1
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1
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9
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2
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centromere near the end
2
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1
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3
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9
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one X and one Y chromosome develops as a male
2
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3
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9
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Female pass on one of their two X chromosomes in each egg cell
2
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5
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Meiosis
3
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Meiosis and sexual life cycles
3
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1
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1
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1
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1
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1
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offspring have same chromosomes as parents, are genetically
identical
3
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1
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Sexual
3
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1
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1
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1
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Fertilization doubles the number of chromosomes each time it occurs
3
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2
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cause doubling of chromosome number every generation
3
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2
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halving of chromosome number happens during mitosis
3
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Bivalents formation and crossing over
3
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1
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2
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1
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2
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After synapsis a process called ""crossing over"" takes place
3
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2
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A junction is created where one chromatid in each of the homologous
chromosomes breajs and rejoins with other chromatid
3
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2
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mutal exchange between the chromatids
3
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2
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chromatids with new combinations of alleles are produced
3
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Random orientation of bivalents
3
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1
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3
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Pole to which each chromosome is attached depends on which way the pair
of chromosomes is facing(called orientation)
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3
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3
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4
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4
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Caused by
3
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1
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Random orientation of bivalents
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1
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Crossing over
Crossing over and random orientation promotes genetic variation(Random
orientation of bivalents, Crossing over)
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Fertilization and genetic variation
3
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1
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5
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1
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Transcription and gene expression
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The direction of Transcription
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1
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1
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Promoter
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2
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Transcription begins near this site
4
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Nucleosomes regulate transcription
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1
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2
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1
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2
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2
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2
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2
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Modifications
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1
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1
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Addition of an acetyl group
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1
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1
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Addition of methyl group
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1
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1
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Addition of a phosphate group
4
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1
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2
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Stages of Meiosis
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Prophase l
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1
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1
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Homologous chromosomes pair(synapsis)
5
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3
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2
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2
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Spindle microtubles move homologous pairs to equator of cell
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2
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3
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3
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Homologous pairs separated, one chromosome of each pair moves to each
pole
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Telophase l
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1
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4
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reduction of chromosome number from diploid to haploid completed

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5
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3
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5
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5
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Chromosomes condense and become visible
5
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Metaphase ll
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Anaphase ll
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1
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8
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8
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Chromatids reach opposite poles
5
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2
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8
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Cytokinesis occurs

6
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1
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1
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Gametes are cells that fuse together to produce a single cell
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2
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2
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2
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Fusion of gametes results in zygotes
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2
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3
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3
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During meiosis a diploid nucleus divides twice, producing four haploid nuclei

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1
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Haploid nuclei only contain one copy of each gene
6
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2
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3
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1
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3
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If two different alleles were present
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3
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Each haploid nucleus will receive either one of the alleles or the other
allele(not both)
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4
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3
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Allows new combinations to form in offspring
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Dominant, recessive and co-dominant alleles
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1
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4
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1
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4
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2
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A cross between tall pea plant and dwarf pea plant- all offspring
were tall
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2
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4
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1
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4
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Reason for dominance of one allele is tat this allele codes for a protein that
is active and carries out a function
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3
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Recessive allele codes for non-functional protein
6
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Genetic diseases

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1
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5
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1
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5
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2
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5
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3
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5
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4
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Cystic Fibrosis
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2
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5
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1
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5
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2
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5
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3
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5
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4
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Huntington's Disease
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Sex-linked genes
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1
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6
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due to their location on sex chromosomes
6
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Segregation and Independent assortment
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1
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7
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1
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7
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Independent Assortment

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2
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Observation that the alleles of one gene segregate independently of the
alleles of other genes
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2
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Genes found on different chromosomes
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2
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1
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7
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2
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do segregate independently as a result of meiosis
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2
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Genes fond on the same chromosomes
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2
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1
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7
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3
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do not segregate independently
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2
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2
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exception
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2
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2
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1
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7
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3
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1
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Crossing over between genes occurs more frequently the
further the separation of genes
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2
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2
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2
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make it appear that the genes are unlinked
6
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Linked Genes
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1
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8
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All genes on a chromosome are part of one DNA molecule
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3
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8
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1
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8
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2
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8
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2
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Autosomal gene linkage
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3
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2
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9
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9
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Discontinuous Variation
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1
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Blood types
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1
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1
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9
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Continuous Variation
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2
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Two or More genes affect the same Character
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2
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Mendel Experiments
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2
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1
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9
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2
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1
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9
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2
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1
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Range of flower colours was seen
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2
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1
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2
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9
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2
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1
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Gave ratio 1:4:6:4:1
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2
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1
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As number of genes increased, the distribution becomes close to
normal distribution
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2
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1
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1
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9
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2
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2
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1
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9
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2
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2
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2
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9
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2
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2
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2
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Substitution at on locus produces the same effect on
the phenotype as a substitution at another
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2
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1
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1
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2
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9
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2
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2
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2
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Tall parents can produce short child or tall child
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2
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1
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1
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4
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9
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2
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2
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3
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9
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2
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2
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3
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Differences in phenotype between classes are subtle
and the effects of the environmental blur these differences so much
they are undetectable
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2
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1
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1
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2
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Skin Colour
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2
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1
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1
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3
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9
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2
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2
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3
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influence of several genes
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Chi-Squared Tests
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1
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11
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11
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Mated white-eyed specimen to red-eyed fly
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1
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1,200 offspring red eyed
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1
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3 white-eyed flies
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1
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3:1 ratio white to red
F1 Generation(1,200 offspring red eyed , 3 white-eyed flies)
F2 Generation(3:1 ratio white to red )
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2
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11
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Mendel's principle of dominance and recessiveness

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3
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Predict three to one ratio of red to white
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3
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both males and females

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1
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1
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Used to separate proteins or fragments of DNA
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2
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1
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1
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1
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2
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1
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3
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1
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3
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Molecules with negative and positive charges move in opposite
direction
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DNA Amplification by PCR
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1
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2
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1
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2
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2
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2
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3
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2
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4
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2
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4
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Strand Separation
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1
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1
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Use Heat
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1
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1
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95 degrees

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1
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2
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2
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4
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1
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2
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4
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DNA taq polymerase builds new strand
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1
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3
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72 degrees
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1
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Repeated Several times
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DNA profiling
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1
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3
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1
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3
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2
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3
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3
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3
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3
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uses Restriction endonuclease
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1
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Fragments separated
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1
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1
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3
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5
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3
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5
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Individual's DNA profile
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1
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Profiles can be compared
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DNA fingerprinting
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1
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4
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1
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4
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2
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4
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3
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4
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3
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Would create fragments of DNA that are characteristic length
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1
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1
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Fragments analyzed by gel
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1
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1
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1
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4
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3
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Difference in length called polymorphism
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1
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2
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unique to person
See Also: Unique pattern is formed
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DNA sequencing
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1
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5
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Sanger is common method
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2
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Steps to Sanger method
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2
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1
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5
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1
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1
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5
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1
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2
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5
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1
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2
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ddA
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2
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1
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2
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5
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1
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2
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ddG
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2
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1
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4
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5
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1
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Replication of DNA

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2
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2
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uses radioactively labelled primer
7
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2
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2
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ddN's compete with regular nucleotides for binding
7
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2
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2
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some ddN's bind the DNA immediately after it has been primed
while other bind after various lengths have been created
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2
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3
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5
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1
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1
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5
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1
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Interpreting the results
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2
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4
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strands stopped by ddN's
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2
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4
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how far strands traveled shows sequence of DNA
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Genetic Modification
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1
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6
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Produced
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2
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Insulin
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2
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New characteristics to animals species
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2
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New varieties of crop plants
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Clones
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1
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7
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1
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7
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2
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7
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Natural Methods of Cloning
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2
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Species can reproduce asexually
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2
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Plants can produced by asexual reproduction
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3
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7
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1
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7
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1
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process of embryo to divide into two or more parts and each part to
develop into separate individual with all body parts
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3
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2
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7
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2
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7
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2
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Cells od an adult animal are differentiated
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3
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2
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DNA Structure and replication
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Rosalind Franklin's investigation of DNA structure
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1
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1
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Deductions
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2
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Molecule was helical shape
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2
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angle of cross shape showed the pitch of the helix
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2
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Distance between the horizontal bars showed turns of the helix to be
3
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1
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4
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2
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2
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Genetic material of virus was protein or DNA
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2
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2
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1
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3
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3
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Variable Number Tandem Repeat(VNTR)
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1
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short nucleotide sequence
8
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1
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shows variations between individuals in terms of the number of time
the sequence is repeated
8
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1
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Used in DNA profiling
8
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Non-Coding regions of DNA have important functions
8
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1
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4
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1
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4
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Non-Coding Sequences
8
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2
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Functions
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2
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1
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4
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1
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1
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4
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1
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2
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4
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1
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role in regulation of gene expression
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2
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2
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Enchancers
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2
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2
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Silencers

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4
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occurs on ends of chromosomes
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3
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2

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