Notesale: Turn your study into money

Document Preview

Extracts from the notes are below, to see the PDF you'll receive please use the links above

---

1
...
Chapter Nine Patterns of Inheritance Key Concepts
i
...
Genetics is the study of inherited characteristics (genetic traits) and the genes
that affect those traits
iii
...
A phenotype is the specific version of a genetic trait that is displayed by an
individual
v
...
Diploid cells have two copies of every gene: one copy inherited from the male
parent the other from the female parent homozygotes have the same two
alleles for a gene heterozygote have two different alleles
vii
...
Mendel’s laws of inheritance help us predict the phenotypes of offspring from
the known genotypes of the parents
ix
...
Many aspects of an organism’s phenotypes are determined by multiple genes
that interact with one another and with the environment so offspring with
identical genotypes can have very different phenotypes
...
Chapter Nine Patterns of Inheritance Vocab
i
...

ii
...

iii
...

iv
...

v
...

vi
...

vii
...

viii
...

ix
...


x
...

xi
...

xii
...

xiii
...

xiv
...

xv
...

xvi
...

xvii
...

xviii
...

xix
...

xx
...
The law of independent assortment states that when gametes form, the two
copies of any given allele are sorted independently of any two alleles of other
genes
...
Incomplete dominance of alleles produces an intermediate phenotype in the
heterozygote
...
Codominance occurs when the effect of both alleles is equally visible in the
phenotype of the heterozygote
...
The situation in which a single gene influences two or more distinctly different
traits is called pleiotropy
...
The term epistasis applies when the phenotypic effect of the alleles of one gene
depends on the presence of certain alleles for another, independently inherited
gene
...
Traits governed by the action of more than one gene are polygenic traits
...
Geneticists estimate there are more than a dozen genes that control melanin
production in our skin, which, when coupled with environmental influences,
results in continuous variation in the trait
...
Complex traits are those that cannot be predicted using Mendel’s laws of
inheritance; complex traits display often display continuous variation in a
population
...
Chapter Nine Patterns of Inheritance Outline
i
...
1 principles of genetics: an overview
1
...
Genetics it’s the study of genes

2
...
A genetic trait is any inherited characteristic of an organism that
can be observed or ducted in some manner
...
Phenotype is the display of a particular version of a genetic trait
in an individual
3
...
Somatic cells are diploids
b
...
Paternal and maternal homologues copies of chromosomes
d
...
Or only one copy of each gene
4
...
Alleles are different versions of genes
b
...
Homozygotes have the same gene in both copies of the gene
d
...

5
...
Dominant means the allele exercises a controlling influence on
the phenotype
b
...
Gene mutations are the source of new alleles
a
...
Controlled crosses help us understand patterns of inheritance
a
...
The parent generation in a genetic cross is called the P
Generation
c
...
When the F1 generation is cross with the F1 generation the
offspring are called the F2 generation
ii
...
2 Basic Patterns of inheritance
1
...
Blending inheritance is where the traits of both parents were
thrown into a bottle and blended up and that is what your
offspring where
2
...
Hybrid offspring are the offspring resulting from a cross
between two pure breads
3
...
Alternative versions of genes cause variation in inherited traits
for example peas have one version of a certain gene that causes
flowers to be purple and another version of the same gene that

causes flowers to be white one individual carries at most two
different alleles for a gene
b
...
7 Mendel reasoned
that white flowers could not reappear in the F2 generation
unless the white flowers allele was present in the F1 plants to
pass on to F2 plants he deduced that the F1 pea plants must
carry two copies of the flower color gene an allele that causes
white flowers and an allele that causes purple flowers
c
...
7 must have
genotype
d
...
Gametes fuse without regard to the allele they carry when
gametes fuse to form a zygote they do so randomly with respect
to the alleles they carry for a gene
...
9
...
Intro
a
...
Law of segregation came from breading single trait such as
flower color or plant height
c
...
Mendel’s single trait crosses revealed the law of segregation
a
...

b
...
Punnett square shows all possible ways that two alleles can be
brought together through fertilization

3
...
Dihybrids are experiments that revolve around two traits
b
...

4
...
All about the probabilities of genetics using the punnet square
iv
...
4 extensions of Mendes laws
...
Intro
a
...
Many alleles display incomplete dominance
a
...
The alleles of some genes are codominant
a
...
A pleiotropic gene affects multiple traits
a
...

5
...
Epistasis applies when the phenotype effect of the alleles of one
gene depends on the presence of certain alleles for another
indecently inherited gene
6
...
Some genes are recapture related
7
...
Polygenic is that they are governed by the action of more than
one gene unlike the traits including skin color in humans
8
...
Complex traits are genetic traits whose pattern of inheritance
cannot be predicted by Mendes laws of inheritance
d
...
9
...
Genes- the basic units of inheritance are segments of DNA that help
determine an organism inherited characteristics or genetic traits
2
...
Alternative version of a gene are celled alleles in a population of many
individuals generally have two copies of each gene one inherited from
the male parent the other from the female

4
...
A dominate allele controls the phenotype of an individual even when
paired with a different allele (heterozygous genotype) a recessive allele
has no phenotypic effect when paired with a dominate allele
6
...

7
...

ii
...
2 basic patterns of inheritance
1
...
In modern terminology Mendes discoveries, can be summarized as
follows
a
...
Offspring inherit one allele of a gene from each parent
c
...
The two copies of a gene separate into different haploid
gametes
e
...
9
...
Mendel’s law of segregation states that the two copies of a gene (the
two alleles) end up in a different gamete during meiosis
2
...
9
...
For some traits, Mendel’s laws, may not predict the phenotype of the
offspring because
a
...
One gene may affect more than one genetic trait
c
...
The environment can alter the phenotype of a gene
e
...
Traits that are crucial for survival tend to be complex traits complex
traits are influenced by multiple genes that interact with one another
and within the environment



---