Question 1

Why is it essential that meiosis produce haploid cells?

Accepted Answer

If meiosis produced diploid cells instead of haploid cells, the number of chromosomes would double with each generation instead of staying the same. This would result in an unsustainable increase in chromosome number, which would ultimately lead to genetic abnormalities and likely death of the organism. Haploid cells are necessary for sexual reproduction to produce diploid offspring, but they are not necessary for asexual reproduction.

Question 2

People who have a single X chromosome are female,while those with XXY sex chromosomes are males.In order to be a female,a human

Accepted Answer

Sex chromosome systems vary in how they work,with the human system requiring no Y be present for an organisms to be female.Please see section 9.2 for more information.

Question 3

In humans,the sex of a child is determined by

Accepted Answer

The sex chromosome in the sperm determines the sex of the child as it will either be an X or a Y chromosome. If the sperm carries an X chromosome, the child will be female and if it carries a Y chromosome, the child will be male. The sex chromosome in the egg is always an X chromosome. The number of autosomes in the egg or sperm does not determine the sex of the child. The number of X chromosomes in the egg also does not determine the sex of the child, as only the sex chromosome in the sperm matters for determining the sex of the child.

Question 4

A diploid cell with 4 chromosomes would produce which of the following after meiosis?

Accepted Answer

During meiosis, a diploid cell undergoes two rounds of cell division resulting in four genetically distinct haploid gametes. In this case, since the starting cell has 4 chromosomes, each gamete will contain 2 chromosomes. Therefore, the correct answer is C) Four genetically-distinct types of haploid gametes.

Question 5

A diploid cell with 6 chromosomes would produce which of the following after meiosis?

Accepted Answer

During meiosis, a diploid cell undergoes two rounds of cell division to form four genetically distinct haploid gametes. Each gamete receives half of the number of chromosomes present in the parent cell. Therefore, a diploid cell with 6 chromosomes would produce 4 haploid gametes, each carrying three chromosomes, giving a total of eight genetically distinct types of haploid gametes, which is option D.

Question 6

Most cultivated bananas are triploid.How could these be generated from diploid parent banana plants?

Accepted Answer

Triploid bananas are generated through a cross between two diploid banana plants followed by nondisjunction in meiosis of the resulting diploid offspring, resulting in a gamete with an extra set of chromosomes. This gamete is then fertilized by a normal haploid gamete, resulting in a triploid banana plant.

Question 7

If a diploid sperm fertilizes a diploid egg it will produce a ____ zygote.

Accepted Answer

Two diploid gametes, if fused, give four sets of chromosomes to the zygote.

Question 8

If a diploid cell goes through meiosis it will generate

Accepted Answer

Meiosis involves two rounds of division resulting in four genetically unique, haploid cells.

Question 9

When a human egg ovulates,it arrests in metaphase II until it is fertilized by a sperm.How many chromosomes are present in the egg at metaphase II?

Accepted Answer

At metaphase II, the human egg has undergone meiosis II and has separated the sister chromatids, leaving only one copy of each chromosome. Therefore, there are 23 chromosomes present, each with only one chromatid.

Question 10

In the section "Investigating Life: A New Species Is Born,but Who's the Daddy?",Tragopogon mirus is a hybrid of T.dubius and T porrifolius.Based on the figure,T.mirus has

Accepted Answer

Tragopogon mirus is an allopolyploid hybrid, meaning it has a complete set of chromosomes from each parent species, T. dubius and T. porrifolius, resulting in 12 chromosomes from each.

Question 11

If a chromosome in one of your bone cells becomes mutated,you will not pass this mutation onto your children because

Accepted Answer

Somatic cells, distinct from germ cells, do not produce gametes for starting a new generation.

Question 12

In the section "Investigating Life: A New Species Is Born,but Who's the Daddy?",T.mirus would normally produce gametes with __ chromosomes.

Accepted Answer

T.mirus is a tetraploid organism, meaning it has 4 sets of chromosomes. Therefore, its normal gametes would contain half of that amount, or 2 sets of chromosomes. In this case, each set would have 6 chromosomes, for a total of 12 chromosomes in each gamete. Therefore, the correct answer is B) 12.

Question 13

Genes A and B are on the same chromosome.What gametes could an individual with the allele combination AABB produce?

Accepted Answer

Each gamete gets one allele per gene.

Question 14

Genes A and B are on the same chromosome.If a person has one chromosome with the alleles AB and a second chromosome with the alleles ab,how could they produce a gamete with a chromosome containing the alleles Ab or aB?

Accepted Answer

Crossing over during meiosis can result in the exchange of genetic material between homologous chromosomes, potentially creating new combinations of alleles on the resulting chromosomes. If crossing over occurred between the A and B genes on one chromosome and the a and b genes on the other chromosome, it could result in a gamete with the AB combination on one chromosome and the ab combination on the other chromosome, producing the Ab or aB combination.

Question 15

Which of the following will occur in meiosis but not in mitosis?

Accepted Answer

Crossing over occurs during meiosis but not in mitosis. This is the exchange of genetic material between homologous chromosomes, which increases genetic variation. Metaphase, cytokinesis, DNA replication, and chromosome condensation all occur in both meiosis and mitosis.

Question 16

If a diploid cell goes through mitosis it will generate

Accepted Answer

Mitosis results in the formation of two identical diploid cells, each containing the same number of chromosomes as the original parent cell. Option A is incorrect as haploid cells are produced after the process of meiosis, not mitosis. Option C is also incorrect as mitosis does not result in the formation of haploid cells. Option D is incorrect as mitosis only generates two diploid cells, not four. Option E is incorrect as diploid cells undergoing mitosis is a normal process in the cell cycle.

Question 17

For a plant to produce diploid sperm and egg ____ must occur during _____.

Accepted Answer

Nondisjunction occurs when chromosome pairs fail to separate during meiosis, resulting in gametes with an abnormal number of chromosomes. If a diploid cell undergoes nondisjunction during meiosis, it can produce diploid gametes.

Question 18

If you mate a donkey (2n = 62)with a horse (2n = 64)you get a mule.A mule is sterile and cannot produce gametes by meiosis because

Accepted Answer

Mules have an odd number of chromosomes (63), which is an uneven number that cannot divide equally during meiosis to form viable gametes. Gametes are essential for sexual reproduction, and without them, mules are sterile.

Question 19

If a haploid cell goes through mitosis it will generate

Accepted Answer

Mitosis results in two genetically identical cells with the same number of chromosomes as the original cell, so a haploid cell will produce two haploid cells.

Question 20

If a haploid cell goes through meiosis it will generate

Accepted Answer

Meiosis typically occurs in diploid cells to produce haploid gametes. A haploid cell cannot undergo meiosis to produce more haploid cells.

Quiz 9: Sexual Reproduction and Meiosis