Inheritance

Question 1

How does genetic variation translate to phenotypic variation?

Answer 1

• Gregor Mendel (Born in Austria, became a monk)

- Observation : Individuals vary for different characteristics of an organism

Question 2

Genotype-

Answer 2

Set of genes in our DNA responsible for a certain trait.

Question 3

Phenotype:

Answer 3

Physical expression or characteristics of that trait.

Question 4

Blending hypothesis:

Answer 4

Different phenotypes blend to uniformity over time.

-Differences in phenotypes amount individuals are lost in offspring and cannot reappear in the population.

Question 5

True Breeding:

Answer 5

Offspring produced by self-pollination always have a given feature of the parent plant.

Question 6

Self-pollinating:

Answer 6

An individual plant that can produce both gametes(sperm and egg) and fertilize itself to produce offspring.

Question 7

Meiosis:

Answer 7

Cell division process that produces sex cells(gametes)
-Homologous chromosomes

•diploid parent cells are reduced to haploid sex cells.

Question 8

Step 1 Meiosis:

Answer 8

Start with diploid parent cell
Homologous chromosomes
1 of each paternal & maternal sex cells (gametes)
Paternal 23 and Maternal 23 = 46 chromosomes

Question 9

Step 2 Meiosis:

Answer 9

The Chromosomes duplicate

Question 10

Step 3 Meiosis:

Answer 10

First Cell Division
• Homologous Chromosomes separate
* Two daughter cells

Question 11

Step 4 Meiosis:

Answer 11

Second Cell Division
• sister chromatids separate
* four haploid daughter cells

Question 12

Dominance Patterns:

Dominant allele:

Answer 12

determines an organism’s phenotype will be expressed even if an individual has only copy of the dominant allele.

Question 13

Dominance patterns:

Recessive allele:

Answer 13

recessive phenotype masked by dominant phenotype; recessive phenotype only expressed if 2 copies of recessive allele.

Question 14

Simple Dominance:

Answer 14

When two different alleles are present in an individual, one allele is dominant and one is preferably expressed.

Question 15

Combination of alleles for a trait:

Answer 15

genotype
ex
Dominant genotype= AA,Aa
Recessive genotype = aa

Question 16

Molecular Basis of dominance:

Answer 16

• DNA codes for proteins – Different alleles may code for different versions of proteins or absence of proteins
• Type, function, presence/absence of protein determines phenotype
• Dominant allele: allele of this phenotype is fully expressed
• Recessive allele: allele of this phenotype is masked in presence of dominant allele

Question 17

homozygous (dominant) genotype:

Answer 17

AA= Dominant alleles

Question 18

homozygous (recessive) genotype:

Answer 18

aa= recessive alleles

Question 19

Heterozygotes genotype:

Answer 19

Aa= 1 dominant and 1 recessive alleles

Question 20

Punnett squares:

Answer 20

Powerful predictive tool,

Can determine the probability of the offspring inheriting genetic disorders based on parent’s genotype and dominance.

Question 21

Codominance:

Answer 21

heterozygotes express the phenotype of both alleles.

Question 22

Incomplete Dominance: ​

Answer 22

​Heterozygotes express a third unique phenotype that is an intermediate between the dominant and recessive phenotype.

Question 23

Epistasis:

Answer 23

the expression of one gene’s phenotype is affected by the expression of a second gene.

Question 24

Discrete Variation:

Answer 24

organisms vary in traits that can be broken into categories on an “either or” basis.

Question 25

Continuous variation:

Answer 25

organisms vary in traits along a continuum

- Can’t be explained by single-gene mechanism.

Question 26

Polygenic Inheritance​:

Answer 26

phenotype is controlled by the additive effects of two or more genes.

Question 27

Pleiotropy:

Answer 27

1 gene affects many different characteristics.

• characteristics often seem unrelated to one another.

Question 28

If the blending model of inheritance is correct, which of the following outcomes would you expect from the hybridization below?
Purple, White or light purple.

Answer 28

Light purple

Question 29

Is Huntington’s Dominant and Recessive?

Answer 29

Dominant

Question 30

Is Tay-Sachs Dominant or Recessive?

Answer 30

Recessive

Question 31

Which of the following accurately describes the outcome of Mendel’s F1 X F1 cross?
If the maternal and paternal Ff•Ff

Answer 31

75% of the F2 generation will display the dominant phenotype; 50% of the F2 will be homozygotes, 50% will be heterozygotes.

Question 32

Question: the couple’s first child is NOT a carrier. Is the couple’s second child more likely to inherit the t allele as a result?
True or False.

Answer 32

False

Question 33

What genotype must a dog have to be chocolate?

BB, Bb, or bb.

Answer 33

Ex.

bb=(recessive) homozygous

Question 34

Based on the dominance patterns for coat color and pigment deposition alleles, which of the following genotypes would result in a yellow lab puppy?
BBEe, Bbee, BBee, or BBEe

Answer 34

Bbee or BBee
Ex.
The (e) gene is recessive so in order to affect the coat color the alleles has to express ee = Yellow color.