Question 1

Which of the following types of cell division actually contains two rounds of cell division?&#10;A)mitosis&#10;B)meiosis&#10;C)cytokenesis

Accepted Answer

Meiosis involves two rounds of cell division, called meiosis I and meiosis II, which result in the formation of four haploid daughter cells. Mitosis only involves one round of cell division, while cytokinesis is the physical splitting of the cytoplasm, which can occur during either mitosis or meiosis.

Question 2

How would you determine if the number of chromosomes in a certain life stage of an organism exhibiting alternation of generations was diploid or haploid?&#10;A)compare the chromosome number before and after mitosis&#10;B)compare the chromosome number before and after meiosis&#10;C)compare the chromosome number before and after cytokenesis

Accepted Answer

To determine if the number of chromosomes in a certain life stage of an organism exhibiting alternation of generations is diploid or haploid, one would compare the chromosome number before and after meiosis. In meiosis, the diploid cell undergoes two rounds of cell division to form four haploid cells, so comparing the chromosome number before and after meiosis can reveal whether the cell in question is haploid or diploid.

Question 3

Researchers found that a certain species of sea slug, Elysia chlorotica, has in its genome a gene for repairing and maintaining chloroplasts.The gene is identical to one found in the algae from which the slugs steal chloroplasts for performing photosynthesis during periods of dietary shortfall.How did the slugs get the gene?

A)through vertical gene transfer
B)through horizontal gene transfer
C)through diagonal gene transfer

B

Accepted Answer

The sea slug likely acquired the gene for repairing and maintaining chloroplasts through horizontal gene transfer, as it acquired the chloroplasts themselves from the algae through a similar mechanism. Horizontal gene transfer is the transfer of genetic material between organisms that are not parent and offspring, and can occur through mechanisms such as viral transfer or uptake of DNA fragments from the environment.

Question 4

The separation of the cytoplasm of a cell during cell division is known as:&#10;A)mitosis&#10;B)meiosis&#10;C)cytokenesis

Accepted Answer

Cytokinesis is the process of dividing the cytoplasm of a cell, which occurs during the final stage of cell division. Mitosis and meiosis refer specifically to the division of the cell's nucleus, and do not involve separation of the cytoplasm.

Question 5

A certain sea slug, Elysia chlorotica, &#34;steals&#34; chloroplasts from algae it normally feeds upon, and then uses the chloroplasts to conduct photosynthesis during times of low food availability.Scientists found that the slug carries a chloroplast-maintenance gene in its genome, a gene identical to one found in the algae.The process by which the slug first acquired the gene is called what?&#10;A)horizontal gene transfer&#10;B)mutation and natural selection&#10;C)vertical gene transfer

Accepted Answer

Horizontal gene transfer is the transfer of genetic material from one organism to another that is not its offspring. In this case, the sea slug likely acquired the chloroplast-maintenance gene from the algae through horizontal gene transfer, allowing it to maintain the stolen chloroplasts and conduct photosynthesis. Mutation and natural selection (B) and vertical gene transfer (C) are not applicable in this scenario.

Question 6

Inhibitors of microtubule synthesis inhibit mitosis by preventing the formation and function of the:&#10;A)chromosomes&#10;B)centrioles&#10;C)spindle

Accepted Answer

The spindle is a structure made of microtubules that forms during mitosis and is responsible for separating the chromosomes. Inhibitors of microtubule synthesis would prevent the formation and function of the spindle, thus inhibiting mitosis. Chromosomes and centrioles are not directly affected by microtubule synthesis inhibitors, although their movement and segregation during mitosis would be inhibited due to the lack of a functional spindle.

Deck 6: Reproduction at the Cellular Level