BIOL 1010 Lecture Notes - Lecture 2: Mendelian Inheritance, Gamete, Phenotype

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24 Nov 2016

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Document Summary

2 pairs of identical alleles are homozygous for the gene controlling that character. An organism that has two different alleles for a gene is said to be heterozygous. Observable traits; phenotype, genetic make up- genotype. Breeding an organism of an unknown genotype with a recessive homozygote is called a test cross- reveals genotype. Monohybrid; 1 pair of allele crossed ratio 3:1, Dihybrid; 2 pairs of alleles crossed 9:3:3:1. Law of independent assortment; each pair of alleles segregates independently of each other during gamete formation. Multiplication rule- to determine the probability we multiply probability of one event by the probability of the other. Addition rule- the probability that any one of two mutually exclusive events will occur is calculated by adding individual properties. The f1 offspring always looked like one of the 2 parental variety because one allele in a pair showed complete dominance. Codominance- 2 alleles affect phenotypes in distinguishable ways.

Related Questions

1. A person is described as a carrier for a particular genetic disease. What does this tell you about their genotype?

2. For any given gene, the principle of independent segregation predicts that each gamete produced as a result of meiosis will contain ____________________

3. A pair of alleles is said to be heterozygous when:

4. In a diploid species, cells can have up to ___ alleles of a particular gene.

5. In a cross between a homozygous dominant parent and a homozygous recessive parent, the number of phenotypic classes observed in the offspring is ______

6. For a person of genotype Xx, the genotype of their gametes may be ______________

7. In a "test cross", an individual of unknown genotype is crossed with a ___ individual to determine the unknown genotype.

8. An albino woman has a child with a phenotypically normal man with no family history of albinism (which is a rare recessive disorder). What percentage of their children are likely to be albino?

9. An individual with the dominant phenotype, but an unknown genotype, is test-crossed, and all of the offspring exhibit the dominant phenotype. The genotype of the unknown individual is ______________

10. If two heterozygous individuals for a recessive disease (carriers) have a child, what is the chance that their child will develop the disease?

11. In a monohybrid cross between two true-breeding parents that both exhibit the dominant phenotype, ___ percent of the offspring will exhibit the recessive phenotype.

12. In a particular type of tomato plant, red fruit is dominant over yellow fruit, and dwarf height is a recessive trait. If two heterozygous plants were crossed, what proportion of the offspring would show the dominant phenotype?

13. In a cross between a BbRr individual and a BBRR one, what do the following represent: BR, Br, bR, br?

14. In humans, the gene that determines whether an embryo develops as a male or a female is carried on _____________

amaranthhare726

QUESTION 1

Jim is blood type A, his brother John is type O and his sister Jane is type AB. What are the genotypes of their parents?

Which of the following is true for alleles that show incomplete dominance?

Heterozygotes have a genotype like the dominant allele.

Homozygotes have a genotype like the recessive allele.

Heterozygotes have a phenotype intermediate between the dominant and recessive alleles.

Homozygotes have the same phenotype as the heterozygotes.

QUESTION 3

Which principle of inheritance concluded that when games are formed in meiosis, the two alleles of each gene separate from one another, and each gamete receives only one allele?

independent assortment

Which term best describes a condition in which alleles at one locus can alter the expression of alleles at another locus?

polygenic inheritance

A single unit of genetic information located on a chromosome defines:

The physical expression (appearance or function) of an organism's genes defines:

genotype

a single characteristic

Palomino horses (golden color with a blond mane) are an incompletely dominant trait produced by the combination of the chestnut color allele and the cream color allele. If you wanted to produce as many palominos as possible, which mating strategy below would be the best choice?

Which term best describes the effect of a single gene on multiple aspects of the phenotype?

polygenic inheritance

QUESTION 9

Which term best describes the separate expression of both alleles for a single trait in the same cell?

polygenic inheritance

QUESTION 10

One form of a gene found on a single chromosome defines:

A chocolate lab (whose mother was a yellow lab) is mated with a black lab whose genotype is BbEe. What fraction of the offspring would be expected to be yellow labs?

What type of allele is always expressed regardless of whether the individual is homozygous or heterozygous for it?

Both the dominant and recessive alleles

Given the parents AABBGgHhrr Ã AabbGgHhRr, assume simple dominance and independent assortment. What proportion of the progeny will be expected to have the genotype AaBbggHHrr?

___________________ is defined as having two of the same type of allele for a particular trait.

The physical position of an allele on a single chromosome defines:

Which term best describes two or more genes affecting the phenotype in an additive fashion?

codominance

polygenic inheritance

1. Ifa species of flower has the allele R (red) which is incompletelydominant to the allele r (white) what color is the genotype of anindividual with a red flower? Choose as many as areappropriate. (Points: 2) RR
Rr
rr
R
r

2. A gene can be defined as... (Points :2)

alternateforms of the DNA for a trait
geneticcombination that determines the observable form of a trait
partof the DNA that codes for a specific protein
theobservable form of a trait

3. A homozygote is an individual in which(Points : 2)

allelesof the gene pair are different
allelesof the gene pair are identical
genesare homolgous
traitsare passed from parents to progeny

4. Which of the following might be aphenotype? (Points : 2)

A
Aa
pinkflowers
AaDd

5. What does "F2 generation" refer to? (Points: 2)

theparents
theoffspring of the parental generation
theoffspring of crossing the F1 generation with itself
theoffspring of crossing the F1 generation with the parentalgeneration

6. Which of the following genotypes isheterozygous? (Points : 2)

Aa
AABB
A
a

7. Which statement best describes a dominantallele? (Points : 2)

theallele expressed in the homozygote
theallele expressed in the heterozygote
theallele that is most common in the population
theallele that is lethal