Chapter 15 Biology

Humans are diploid and have 46 chromosomes (or two sets). How many sets of chromosomes are found in each human gamete?

1

Humans are diploid and have 46 chromosomes. How many chromosomes are found in each human gamete?

23

A particular diploid plant species has 48 chromosomes, or two sets. A mutation occurs and gametes with 48 chromosomes are produced. If self-fertilization occurs, the zygote will have _____ set(s) of chromosomes.

4

If a diploid cell undergoes meiosis and produces two gametes with n + 1 chromosomes and two gametes with n− 1 chromosomes, what type of error occurred?

A nondisjunction error occurred in meiosis I, in which both members of a homologous pair migrated to the same pole of the cell.

If a diploid cell undergoes meiosis and produces two gametes that are normal, and one with n − 1 chromosomes, and one with n + 1 chromosomes, what type of error occurred?

A nondisjunction error occurred in meiosis II, in which both sister chromatids of a chromosome migrated to the same pole of the cell.

What kind of cell results when a diploid and a haploid gamete fuse during fertilization?

A triploid cell

What is a nondisjunction?

An error in cell division that causes homologous chromosomes or sister chromatids to move to the same side of the dividing cell

_____ is the process by which haploid gametes form a diploid zygote.

Fertilization

When can nondisjunction occur?

In meiosis, when homologous chromosomes fail to separate, In mitosis, when sister chromatids fail to separate, In meiosis, when sister chromatids fail to separate

Of the following chromosomal abnormalities, which type is most likely to be viable in humans?

Trisomy

Which syndrome is characterized by the XO chromosome abnormality?

Turner syndrome

-Bob has a genetic condition that affects his skin. -Bob's wife, Eleanor, has normal skin. No one in Eleanor's family has ever had the skin condition. -Bob and Eleanor have a large family. Of their eleven children, all six of their sons have normal skin, but all five of their daughters have the same skin condition as Bob. Based on Bob and Eleanor's family history, what inheritance pattern does the skin condition most likely follow?

X-linked dominant

This means that the F1 generation makes gametes with the following genotypes:

YR, Yr, yR, yr

The resulting offspring--the F1 generation--have genotype ______.

YyRr

According to Mendel's law of independent assortment, the alleles for seed color and seed shape are transmitted into gametes in ______.

all possible combinations

Mutant tetraploid plants _____.

are unable to interbreed with a diploid plant

At fertilization, two gametes (egg and sperm) come together. The resulting F2 generation exhibits ______ different phenotypes in the ratio of ______.

four; 9 to 3 to 3 to 1

Most polyploid plants arise as a result of _____.

hybridization

Which of these terms applies to an organism with extra sets of chromosomes?

polyploid

In the P generation, a true-breeding pea plant with genotype YYRR is crossed with a true-breeding plant with genotype ______.

yyrr