1.
Which of the following best describes this diagram?
Correct Answer
A. Chromosome
Explanation
The diagram is best described as a chromosome because it represents a condensed and organized structure of DNA. Chromosomes are made up of chromatin, which is a complex of DNA and proteins. The diagram does not specifically show sister chromatids, homologs, or duplicated chromosomes, so these options can be ruled out. Therefore, the best description for the diagram is chromosome.
2.
Which of the following best describes this diagram?
Correct Answer
C. Homologous Chromosomes
Explanation
Homologous chromosomes are pairs of chromosomes that have the same genes at the same loci, but potentially different alleles. They are similar in size, shape, and carry genes for the same traits. In the diagram, the two chromosomes shown are similar in appearance and are likely to be homologous chromosomes. Therefore, the best description for this diagram is "Homologous Chromosomes."
3.
Which of the following best describes this diagram?
Correct Answer
B. Sister Cromatids
Explanation
The diagram is best described as Sister Chromatids. Sister chromatids are two identical copies of a single chromosome that are joined together by a centromere. They are formed during the S phase of the cell cycle and are held together until they separate during cell division. This diagram likely shows two identical copies of a chromosome held together by a centromere, representing sister chromatids.
4.
Which of the following best describes what is seen in this diagram?
Correct Answer
B. Tetrad
Explanation
A tetrad is a structure formed during meiosis where two homologous chromosomes pair up and undergo genetic recombination. In the diagram, if what is seen represents a pair of homologous chromosomes in close proximity, it can be inferred that the correct answer is tetrad.
5.
The "trading" of alleles between the two chromosomes in this tetrad takes place in:
Correct Answer
A. PropHase I
Explanation
During Prophase I of meiosis, homologous chromosomes pair up and undergo crossing over, which is the exchange of genetic material between non-sister chromatids. This process leads to the mixing and recombination of alleles between the two chromosomes in the tetrad. Therefore, Prophase I is the stage where the "trading" of alleles takes place.
6.
What part of cell division does this represent?
Correct Answer
C. InterpHase
Explanation
Interphase is the phase of the cell cycle in which the cell prepares for division by growing, replicating its DNA, and synthesizing proteins. It is the longest phase of the cell cycle and consists of three stages: G1, S, and G2. During interphase, the cell carries out its normal functions and prepares for the upcoming division. Prophase I and Prophase II are specific stages of meiosis, while cytokinesis is the final stage of cell division where the cytoplasm divides. Therefore, the correct answer is Interphase.
7.
What stage of Meiosis does this represent?
Correct Answer
A. PropHase I
Explanation
This represents Prophase I of Meiosis. During Prophase I, the chromosomes condense and pair up, a process called synapsis. This is also when crossing over occurs, where genetic material is exchanged between homologous chromosomes. The nuclear envelope breaks down, and the spindle fibers begin to form. This stage is characterized by the formation of structures called tetrads, consisting of two pairs of sister chromatids. This is a crucial stage for genetic recombination and the introduction of genetic diversity in offspring.
8.
The spindle fibers in this stage are pulling apart...
Correct Answer
B. Homologous pairs of chromosomes
Explanation
In this stage, the spindle fibers are pulling apart homologous pairs of chromosomes. Homologous chromosomes are pairs of chromosomes that carry the same genes, one inherited from each parent. During cell division, the spindle fibers attach to the chromosomes and separate them, ensuring that each new cell receives one copy of each homologous chromosome. This process is crucial for maintaining genetic diversity and ensuring the proper distribution of genetic material to the daughter cells.
9.
Which of the following is NOT happening in this stage?
Correct Answer
A. Disappearing of nuclear envelopes
Explanation
During the stage mentioned, the process of cell division is occurring. The nuclear envelopes are responsible for enclosing the nucleus, and in this stage, they are not disappearing. Instead, they break down and fragment into small vesicles to allow the genetic material to be distributed to the daughter cells. Therefore, the disappearing of nuclear envelopes is NOT happening in this stage.
10.
What stage is represented by this diagram?
Correct Answer
B. PropHase II
Explanation
The diagram represents Prophase II. In Prophase II, the nuclear envelope breaks down, and the spindle fibers form. The chromosomes condense and become visible. This stage occurs during the second division of meiosis, where the chromosomes do not replicate again before entering Prophase II.
11.
Which stage is best represented in this diagram?
Correct Answer
B. MetapHase II
Explanation
The diagram represents a stage where the chromosomes are aligned along the equatorial plane of the cell. This is characteristic of metaphase, specifically metaphase II, as the presence of two cells suggests that the process of meiosis has already occurred once. In metaphase II, the chromosomes align at the equator in each of the two daughter cells, preparing for their separation in the subsequent stages of meiosis.
12.
In this stage, the spindle microtubules are pulling apart...
Correct Answer
A. Sister chromatids
Explanation
During this stage, known as anaphase, the spindle microtubules are responsible for separating the sister chromatids. Sister chromatids are two identical copies of a single chromosome that are held together by a structure called the centromere. The spindle microtubules attach to the centromeres and pull the sister chromatids towards opposite poles of the cell, ensuring that each new cell receives a complete set of chromosomes. This process is crucial for the accurate distribution of genetic material during cell division.
13.
When this cell division is complete, how many chromosomes will be in each gamete?
Correct Answer
C. Haploid number
Explanation
When this cell division is complete, each gamete will have the haploid number of chromosomes. This means that the number of chromosomes in each gamete will be half of the original number of chromosomes in the cells.
14.
The chromosomes appear to be...
Correct Answer
A. Unwinding back into chromatin fiber
Explanation
The correct answer is unwinding back into chromatin fiber. This is indicated by the use of the phrase "appear to be," suggesting that the chromosomes were previously in a condensed state and are now returning to a more relaxed and unwound form known as chromatin fiber.
15.
One difference between prophase of mitosis and prophase of meiosis is proteins cause homologous chromosomes to stick together to form tetrads in meiosis.
Correct Answer
A. TRUE
Explanation
During prophase of meiosis, proteins, specifically synaptonemal complexes, facilitate the pairing of homologous chromosomes, resulting in the formation of tetrads. This process is known as synapsis and is unique to meiosis. In contrast, during prophase of mitosis, homologous chromosomes do not pair up and form tetrads. Therefore, the statement that proteins cause homologous chromosomes to stick together to form tetrads in meiosis is true.
16.
Meiosis results in:
Correct Answer
D. 4 daughter cells with half the number of chromosomes as parent cells
Explanation
Meiosis is a type of cell division that occurs in sexually reproducing organisms. It involves two rounds of division, resulting in the formation of four daughter cells. These daughter cells are genetically different from each other and from the parent cell. Additionally, meiosis reduces the number of chromosomes in each daughter cell by half, ensuring that when these cells combine during fertilization, the resulting offspring will have the correct number of chromosomes. Therefore, the correct answer is "4 daughter cells with half the number of chromosomes as parent cells."
17.
Separation of tetrads is to prophase I as ________________ is to Prophase II.
Correct Answer
B. Separation of sister chromatids
Explanation
During prophase I of meiosis, tetrads are formed when homologous chromosomes pair up. The separation of tetrads refers to the separation of these paired homologous chromosomes. Similarly, during prophase II of meiosis, sister chromatids, which are the replicated copies of each chromosome, become visible. The separation of sister chromatids occurs during anaphase II, where the chromatids are pulled apart to opposite poles of the cell. Therefore, the separation of sister chromatids is the equivalent process to the separation of tetrads in prophase I.
18.
Meiosis results in...
Correct Answer(s)
A. Haploid cells
B. Gametes
C. 4 daughter cells
D. Cell division
Explanation
Meiosis is a type of cell division that occurs in sexually reproducing organisms. It involves two rounds of division, resulting in the formation of four daughter cells. These daughter cells are haploid, meaning they contain half the number of chromosomes compared to the parent cell. The purpose of meiosis is to produce gametes, which are specialized cells involved in sexual reproduction. Therefore, the correct answer includes all the options mentioned: haploid cells, gametes, 4 daughter cells, and cell division.
19.
Diploid is to mitosis as _____________________ is to ______________________
Correct Answer
B. Haploid: Meiosis
Explanation
In mitosis, diploid cells divide to produce two identical diploid daughter cells. Similarly, in meiosis, haploid cells divide to produce four non-identical haploid daughter cells. Therefore, the relationship between diploid and mitosis is the same as the relationship between haploid and meiosis.
20.
Nuclear envelopes do not reappear before Prophase II.
Correct Answer
B. FALSE
Explanation
The statement is false because nuclear envelopes do reappear before Prophase II. In Prophase II of meiosis, the nuclear envelope breaks down just like in Prophase I. However, in Telophase I, the nuclear envelope reassembles around the separated chromosomes before they enter Prophase II. Therefore, the correct answer is false.