chap 8

Why are no two gametes exactly alike genetically? Because each gamete has a different combination of parental chromosomes that is the result of both crossing over and independent assortment Because cell membranes are unique for each gamete Because each gamete undergoes a slightly different version of mitosis during its formation Because each gamete has a different combination of parental chromosomes Because each gamete has chromosomes produced through crossing over

Because each gamete has a different combination of parental chromosomes that is the result of both crossing over and independent assortment

How does meiosis generate genetic diversity? Homologous chromosomes cross over during prophase I. During metaphase I, chromosomes align randomly. During prophase II, chromosomes exchange material. Homologous chromosomes cross over during prophase I, and during metaphase I, chromosomes align randomly. During metaphase I, chromosomes align randomly, and during prophase II, chromosomes exchange material.

Homologous chromosomes cross over during prophase I, and during metaphase I, chromosomes align randomly.

Which of the following allows sexual reproduction to occur generation after generation? Meiosis Mitosis Crossing over Independent assortment Cytokinesis

Meiosis

If a cell begins meiosis with a 2n (diploid) number of 16, how many chromosomes are there in the cell at anaphase I? 8 32 64 128 16

16

If a cell begins meiosis with a 2n (diploid) number of 16, how many chromosomes are there in the cell at prophase I? 8 32 64 128 16

16

If a cell has 30 chromosomes before mitosis, how many does each daughter cell have afterward? 10 20 30 15 25

30

A human somatic (body) cell has __________ chromosomes. 16 23 46 26 48

46

If a cell begins meiosis with a 2n (diploid) number of 16, how many chromosomes are there in each cell at metaphase II? 8 16 32 64 128

8

A human skin cell, in prophase of mitosis, contains 46 chromosomes. How many chromatids does it contain in total? 92 46 23 23 or 46, depending on when during prophase you look at the cell

92

Which of the following is true about prophase I? It can occur only during wound healing. It involves division of the cytoplasm. It involves pairing up of homologous chromosomes. Condensed chromosomes begin to uncoil to form chromatin. It occurs only during mitosis.

It involves pairing up of homologous chromosomes.

Which of the following is true about meiosis II? It results in the production of two haploid cells. It requires homologous chromosomes to pair up. It results in the production of four haploid cells. It results in cells that have two complete sets of chromosomes. It is a process by which genetic material is exchanged between homologous chromosomes.

It results in the production of four haploid cells.

Which of the following terms describes a failure of chromosomes to sort properly during meiosis? Inversion Translocation Deletion Nondisjunction

Nondisjunction

During which phase of the cell cycle does DNA replication occur? S G2 G1 M Cytokinesis

S

Which of the following is the last stage of mitosis? Telophase Anaphase Prophase Metaphase Cytokinesis

Telophase

While working in a medical clinic, you are asked to assist in the care of a 16-year old female patient who has not yet begun menstruating. You also notice that she is small in stature and has a wider than average neck. You suspect that she might have __________. Turner syndrome red-green colorblindness hemophilia sickle-cell anemia Huntington's disease

Turner's Syndrome

During meiosis, homologous chromosomes separate at __________. prophase I metaphase I anaphase I metaphase II anaphase II

anaphase I

Homologous chromosomes __________. carry the same genes carry the same alleles carry the same DNA sequence are inherited from the father only are inherited from the mother only

carry the same genes

Crossing over between homologous chromosomes normally occurs __________. during mitosis during anaphase II during fertilization during prophase I

during prophase I

In humans, meiosis produces cells that are __________. haploid, called gametes haploid and identical haploid, called somatic cells diploid and identical

haploid, called gametes

A karyotype __________. is a picture of chromosomes arranged in ordered pairs displays chromosomes from multiple species of a normal human cell shows 48 chromosomes of a normal woman will have both an X and a Y chromosome

is a picture of chromosomes arranged in ordered pairs

The number of chromosomes found in a somatic eukaryotic cell __________. can vary if the organism is young or old can vary from cell to cell is constant during its entire life will be larger if the organism is an animal rather than a plant will decrease during mitosis

is constant during its entire life

Diploid cells become haploid during __________. meiosis II mitosis meiosis I meiosis II and mitosis meiosis I and mitosis

meiosis I

Plant cells divide by __________. cytokinesis without mitosis mitosis without cytokinesis mitosis followed by cytokinesis by cell plate formation Cytokinesis by cell plate formation only

mitosis followed by cytokinesis by cell plate formation

The sex of a human fetus is determined by the __________. age of the mother age of the father time of conception sex chromosome found in the egg sex chromosome found in the sperm

sex chromosome found in the sperm

In meiosis II, __________. sister chromatids are separated into different daughter cells homologous chromosomes are separated into different daughter cells haploid cells fuse to make a diploid cell crossing over occurs

sister chromatids are separated into different daughter cells