Bio 3 Exam Chapter 12

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

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

Which syndrome is characterized by the XO chromosome abnormality?

Turner syndrome

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

A triploid cell

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

Trisomy

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.

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.

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

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

Fertilization

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

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

Polyploid

Mutant tetraploid plants _____.

are unable to interbreed with a diploid plant

Most polyploid plants arise as a result of _____.

hybridization