BIOB11H3 Lecture Notes - Lecture 1: Gregor Mendel, Gamete

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ivorygoat684

19 Jul 2019

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Document Summary

Gene as a unit of inheritance: gregor mendel experimented by cross breeding pea plants over a number of generations and observed different plant characteristics, any given characteristic of the plant is governed by distinct units of inheritance. These units are called genes: each individual has two copies of a gene, one from each parent. These alternate forms of the gene are called alleles. These alleles can be dominant or recessive: when genes are homozygous, two alleles are the same copies. When genes are heterozygous, the two alleles are different: each reproductive cell (called the gamete) contains only one copy of the gene (allele) for a particular trait. Therefore, the progeny will have two copies of the gene for that trait (one from each parent) Dominant and recessive alleles: the alleles can be identical (homozygous) or non-identical (heterozygous, a dominant allele is an allele that determines the phenotype (the observable trait) of an individual.

Related Questions

When a parent who is heterozgyous for a trait is crossed with a parent who is heterozygous for a trait, the offspring will:

(remember homozygous means two of the same alleles and heterozygous means two different alleles)

Select one:

a. have 3 out of 4 the dominant phenotype and 1 out of 4 the recessive phenotype

b. have 2 out of 4 the dominant phenotype and 2 out of 4 the recessive phenotype

c. all have the dominant phenotype

d. have 1 out of 4 the dominant phenotype

When a parent who is heterozgyous for a trait is crossed with a parent who is homozygous dominant for a trait, the offspring will:

(remember homozygous means two of the same alleles and heterozygous means two different alleles)

Select one:

a. all have the recessive phenotype

b. all will have the dominant allele

c. all be homozygous dominant genotype

When a parent who is heterozgyous for a trait is crossed with a parent who is heterozygous for a trait, the offspring will:

(remember homozygous means two of the same alleles and heterozygous means two different alleles)

Select one:

a. have 3 dominant phenotypes, 2 heterozygous genotypes, and 1 homozygous recessive genotype

b. have 1 dominant phenotype, 2 heterozygous genotypes, and 1 homozygous recessive phenotype

c. have all dominant phenotypes, 2 heterozygous genotypes, and 1 homozygous recessive genotype

When doing Punnett squares for fur, the letter f represents ______ and the letter F represents _____.

Select one:

a. the recessive allele, the dominant allele

b. the dominant allele, the recessive allele

c. the dominant gene, the recessive gene

d. the recessive gene, the dominant gene

10.

When a parent who is heterozgyous for a trait is crossed with a parent who is homozygous recessive for a trait, the offspring will:

(remember homozygous means two of the same alleles and heterozygous means two different alleles)

Select one:

a. be half heterozygous and half homozygous recessive

b. be all heterozygous

c. be all homozygous recessive

d. be all homozygous dominant

Each chromosome has one allele for each of its genes. That allele may confer a functional or nonfunctional protein.

Each chromosome has a unique combination of two alleles for each of its genes. If the alleles are different, then the gene will encode a nonfunctional protein.

Each chromosome has three or more alleles for each of its genes. All alleles on a chromosome are either dominant or recessive, conferring either functional or nonfunctional proteins.

Each chromosome that has only dominant alleles and encodes only functional proteins is called an autosome.

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.