chapter 13 master lab

Which processes lead to most genetic variation in sexually reproducing organisms?

independent assortment of chromosomes in meiosis crossing over random fertilization

Human gametes are produced by _____.

meiosis

Homologous pairs of chromosomes are lined up independently of other such pairs during _____.

metaphase I

Crossing over, resulting in an increase in genetic variation, occurs between _____.

nonsister chromatids of homologous chromosomes

During _____ a spindle forms in a haploid cell.

prophase II

A radiation accident leads to a damaged gene in yeast Saccharomyces cerevisiae, which leads to improper function of that gene. If this species reproduces asexually, which offspring will inherit a copy of the damaged gene?

All the offspring: Asexual reproduction results in identical offspring.

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

Which of these gametes contains one or more recombinant chromosomes?

B and C

Which of the following statements about meiosis and mitosis is true?

Meiosis II is similar to mitosis in that sister chromatids of each chromosome separate. Submit

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. Submit

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

A triploid cell

If a cell has 24 chromosomes, how many chromosomes would each of its four daughter cells have after meiosis?

12

A diploid organism whose somatic (non-sex) cells each contain 32 chromosomes produces gametes containing _____ chromosomes.

16

In human gamete production there is an average of _____ crossover events per chromosome pair.

2-3

Normal human gametes carry _____ chromosomes.

23. This is the number of chromosomes in a single set of human chromosomes.

What is the ploidy of organisms that have two sets of chromosomes?

2n

Which of these gametes contain one or more recombinant chromosomes?

B, C, F, and G

Which of these cells is (are) haploid?

C and D Once meiosis I is completed, cells are haploid.

Which structure is directly correlated with the production of genetic variability in the daughter cells produced during meiosis?

Chiasma

True or false? A haploid organism has one pair of homologous chromosomes.

False

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

What is the composition of a tetrad at the beginning of prophase I?

One pair of homologous chromosomes Submit

A particular plant species can reproduce both sexually and asexually. When samples of this plant are grown in an environment where a harmful bacterial pathogen is abundant, the plants that survive are likely to have been produced primarily through what type of reproduction?

Sexual

What information can not be obtained from an individual's karyotype?

The sequence of bases of a particular gene Submit

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 :vTurner syndrome is characterized by a chromosome pattern of XO, or one X chromosome and no Y chromosome.