Question 1

The life cycle of a sexually reproducing organism must includes which processes?

Accepted Answer

A sexually reproducing organism must undergo mitosis to produce body cells and meiosis to produce gametes. The fusion of gametes during fertilization is also necessary for the formation of a new organism with unique genetic material. Therefore, the life cycle of a sexually reproducing organism includes mitosis, meiosis, and fusion of gametes. Options A, C, and E do not fully include all of these necessary processes. Option D only includes mitosis, which is not enough for the life cycle of a sexually reproducing organism.

Question 2

A species that has three pairs of homologous chromosomes can have how many different combinations of chromosomes in the gametes?

Accepted Answer

Each pair of homologous chromosomes can separate independently during meiosis, resulting in 2² = 4 possible combinations per pair. With three pairs of homologous chromosomes, there are 4^3 = 64 possible combinations, but the question asks for the number of different combinations in the gametes, which is half that number (since gametes have only one set of chromosomes). Therefore, the correct answer is 4^3 ÷ 2 = 8.

Question 3

Which of the following mutations will not alter the amount of genetic material on the chromosomes?

Accepted Answer

Inversion is a type of chromosomal mutation where a segment of the chromosome is inverted or reversed in direction. This does not change the amount of genetic material on the chromosome. The other choices - duplication, simple translocation, deficiency, and inversion and simple translocation - all involve changes in the amount of genetic material on the chromosome.

Question 4

For any given species,cells in metaphase II of meiosis would contain 2* more genetic material than cells in metaphase of mitosis.

Accepted Answer

Cells in metaphase II of meiosis have undergone two rounds of cell division resulting in four haploid daughter cells, each with half the number of chromosomes as the original parent cell. Therefore, they would have half the amount of genetic material as the original parent cell or cells in metaphase of mitosis, which have not undergone any rounds of meiosis yet.

Question 5

Mitotic cell division is never used by organisms as a means of reproduction.

Accepted Answer

Some organisms, such as bacteria and some protists, can reproduce through mitotic cell division. However, it is not the primary means of reproduction for most multicellular organisms, which typically use sexual reproduction.

Question 6

In a tetraploid species,how many sets of chromosomes would a euploid individual possess?

Accepted Answer

A tetraploid species has four sets of chromosomes. Therefore, a euploid individual in a tetraploid species would possess all four sets, making the answer B, 4.

Question 7

The centromere

Accepted Answer

The centromere is the region of DNA where sister chromatids are held together, playing a crucial role during cell division.

Question 8

A chromosome with the centromere located two-thirds of the distance from its end could be classified as

Accepted Answer

The answer of A chromosome with the centromere located two-thirds...

Question 9

When a gamete that is lacking a sex chromosome due to nondisjunction has fused with a gamete carrying an X chromosome,this type of abnormality leads to ________.

Accepted Answer

Nondisjunction of sex chromosomes during gamete formation can lead to Turner syndrome when a gamete lacking a sex chromosome (X or Y) fuses with a normal gamete carrying an X chromosome. This results in a genotype of X0, in which the individual only has one sex chromosome (X) instead of the typical XX or XY.

Question 10

Synaptonemal complexes form during

Accepted Answer

Synaptonemal complexes form during prophase of meiosis I.

Question 11

A female who inherits an extra X chromosome will have

Accepted Answer

Triple X syndrome is the condition in which females inherit an extra X chromosome.

Question 12

In mitosis and cytokinesis,the main difference between plant and animal cells is that

Accepted Answer

The main difference between plant and animal cells in mitosis and cytokinesis is how they separate the daughter nuclei. Plants produce a cell plate, which eventually divides the cell into two daughter cells, while animals form a cleavage furrow that pinches the cell membrane inward to separate the cell.

Question 13

Sister chromatids separate during

Accepted Answer

Sister chromatids separate during anaphase of meiosis II, where the spindle fibers pull the chromosomes towards opposite poles of the dividing cell. During anaphase II, the centromeres split, and each sister chromatid is then considered a separate chromosome.

Question 14

The karyotype of a normal human male would show a total of 23 pairs of homologous chromosomes.

Accepted Answer

A normal human male karyotype would show 22 pairs of homologous chromosomes and 1 pair of sex chromosomes (XY), which are not homologous.

Question 15

A diploid queen honeybee produces eggs by meiosis.Some of these eggs are never fertilized,while the rest are.These unfertilized eggs develop into haploid male honeybees.This can be an example of sexual reproduction.

Accepted Answer

This is an example of sexual reproduction because it involves the fusion of haploid male and female gametes (sperm and eggs) to produce a diploid zygote that develops into a new individual. The production of haploid males is part of the honeybee life cycle and is a mechanism for increasing genetic diversity in the population.

Question 16

Meiosis I produces ________ cells,and meiosis II produces _________ cells.

Accepted Answer

Meiosis I produces two haploid cells, and meiosis II produces four haploid cells. Therefore, option C is the correct answer. Option A and B are incorrect because meiosis cannot produce diploid cells. Option D and E are also incorrect because meiosis produces haploid cells, not somatic or gametic cells.

Question 17

Put the following steps in the procedure for producing a karyotype in the correct order.
I.Cells are visualized under the microscope.
II.Cells are stimulated to divide.
III.Homologues are organized into sets by matching size and banding patterns.
IV.The cells are exposed to a hypotonic solution.
V.Cells are stained and placed on a microscope slide.

Accepted Answer

The correct sequence for producing a karyotype involves first stimulating the cells to divide (II), then exposing them to a hypotonic solution to swell them for easier visualization (IV), followed by staining and placing the cells on a microscope slide (V). After that, the cells are visualized under the microscope (I), and finally, the homologues are organized into sets by matching size and banding patterns (III).

Question 18

What does NOT happen in the cytokinesis of plant cells?

Accepted Answer

Formation of the cleavage furrow is a process that only happens in animal cell cytokinesis. Plant cells form a cell plate to divide the cytoplasm, and a new cell wall forms between the two daughter cells. The other options, A, B, C, and D, are all processes that occur during plant cell cytokinesis.

Question 19

Homologous chromosomes are identical copies of each other.

Accepted Answer

Homologous chromosomes are not identical copies of each other. They are chromosome pairs that have the same genes at the same loci, but can have different versions of those genes (alleles). This is because one homologous chromosome comes from the individual's mother and the other from the father.

Question 20

Chromosomes are replicated during the ______ phase.

Accepted Answer

Chromosomes are replicated during the S phase, which occurs in the interphase of the cell cycle.

Quiz 13: The Eukaryotic Cell Cycle, Mitosis, and Meiosis