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Example Questions
Example Question #51 : Cellular Division
Human somatic cells have 46 chromosomes. How many chromosomes are present in a human cell during metaphase of mitosis?
A chromosome carries the genetic material for a certain segment of the genome. A chromosome can consist of either one or two chromatids.
During metaphase, there are 46 chromosomes composed of two sister chromatids each that align at the metaphase plate. Then, during anaphase, these chromatids are separated and pulled to opposite poles of the cell. This separation results in 92 separate chromatids in the cell, which are considered 92 chromosomes.
Only germ cells will have 23 chromosomes. These haploid cells result from meiosis, rather than mitosis.
Example Question #52 : Cellular Division
In which stage of mitosis does the nuclear envelope form?
Metaphase
Telophase
Anaphase
Prophase
Telophase
During telophase the chromosomes have been sufficiently separated, and new nuclei can be formed. Telophase functions to prepare the cell for cytokinesis be sealing the chromosomes off from the cytoplasm in a new nuclear envelope.
The nuclear envelope first dissolves during prophase, allowing the chromosomes to migrate into the cytoplasm. They align at the center of the cell during metaphase. Sister chromatids are separated during anaphase, and the cell prepares for the final stages of division during telophase.
Example Question #53 : Cellular Division
Which of the following processes occurs during anaphase of mitosis?
Centrioles separate
Chromosomes condense
DNA is synthesized
Chromosomes decondense
The cell briefly contains 92 chromosomes
The cell briefly contains 92 chromosomes
During metaphase, chromosomes line up along the center of the cell. At this point, each chromosome contains two sister chromatids.
During anaphase, sister chromatids are separated but remain within the same cell cytoplasm.
A chromosome can consist of either one or two chromatid. A single chromatid is considered a chromosome once it has been separated from its pair. During anaphase, each of the cell's 46 chromosomes is split into singular chromatids, and each chromatid is considered a separate chromosome structure for a total of 92 chromosomes. Once the cell completes division, these chromatids are sequestered into separate nuclei and the cell returns to its normal diploid state.
Example Question #51 : Cellular Division
Which of the following occurs during meiosis, but does not occur during mitosis?
Segregation of homologous chromosomes
Chromosome condensation
Separation of sister chromatids
Cytokinesis
Segregation of homologous chromosomes
During mitosis we do not see separation of the homologous chromosomes. This is the reason that meiosis results in a reduction of ploidy and that mitosis does not. Separation of homologous chromosomes occurs after the formation of tetrads, during anaphase I of meiosis.
All of the other answers are processes that occur during both meiosis and mitosis. Both divisions require the condensation of chromosomes and eventual cytokinesis to produce daughter cells. Sister chromatids are separated during anaphase of mitosis, and during anaphase II of meiosis.
Example Question #55 : Cellular Division
Which of the following does not happen during anaphase of mitosis?
Sister chromatid separation
Migration of chromosomes towards opposite ends of the spindle
Chromosome condensation
Degradation of securin
Chromosome condensation
Anaphase is primarily characterized by the separation of the sister chromatids. This process occurs by degrading the protein securin, which binds the chromatids together. By degrading this protein, anaphase physically allows the sister chromatids to separate. Immediately after separation, the sister chromatids begin to migrate towards opposite ends of the spindle. Chromosome condensation occurs during prophase, not anaphase.
Example Question #56 : Cellular Division
In which stage of mitosis do the chromosomes line up along the equatorial plate?
Telophase
Prophase
Anaphase
Metaphase
Metaphase
Metaphase is the stage of mitosis when chromosomes line up along the equatorial plate, so that they may be accurately segregated into two unique cells. Metaphase is the second phase of mitosis, following prophase.
During prophase, chromosomes condense and exit the nuclear envelope to align during metaphase. Anaphase follows metaphase, and is characterized by the separation of sister chromatids. Telophase is the final mitotic stage, during which the cell prepares for cytokinesis.
Example Question #57 : Cellular Division
In animal cells, the process of cytokinesis occurs due to which of the following factors?
The movement of spindle fibers
The sliding of microtubules around the circumference of the cell
The sliding of microtubules near the center of the cell
The fusion of vesicles near the center of the cell
Actin filaments contracting around the circumference of the cell
Actin filaments contracting around the circumference of the cell
Cytokinesis begins shortly after anaphase, when a contractile ring assembles near the equator of the cell. A cleavage furrow is formed and eventually, cytokinesis is completed. Actin filaments are capable of contraction, while tubulin polymers (microtubules) are generally used for cell structure. Microtubules form the spindle fibers used to separate sister chromatids during anaphase, but do not play a significant role in cytokinesis.
Example Question #58 : Cellular Division
In chemotherapy, it is common to use drugs that can stabilize or depolymerize microtubules. Of the following statements, which is correct about these drugs?
The drugs disrupt tumor movement
The drugs disrupt the condensation of chromosomes
The drugs stimulate an immune response
The drugs disrupt mitosis
The drugs disrupt endocytotic processes
The drugs disrupt mitosis
Microtubules are polymers of tubulin, and are components of the cytoskeleton. They are involved in mitosis, during which they are involved in the formation of the mitotic spindles. The drugs in chemotherapy are used in the disruption of mitotic processes. By disrupting microtubules, spindle fibers will be unable to form and the cell will be unable to complete anaphase.
Microtubules are not significantly involved in endocytosis, chromosome condensation, or the immune response. Microtubules are involved in cell motility, but movement of tumors is not a typical symptom of cancer. When tumors spread, it is generally due to cancerous cells being carried by the blood to other regions of the body, and is not directly linked to cell motility or microtubules.
Example Question #351 : Ap Biology
Which of the following is not involved in mitosis?
Crossing over
Nuclear membrane disintegrates
Nucleolus disappears
Chromosome condensation
Sister chromatids separate
Crossing over
Crossing over is the only answer choice that does not occur during mitosis. Crossing over occurs during prophase I of meiosis and involves swapping of genetic information between homologous chromosomes. This require the formation of tetrads, which does not occur during mitosis.
During prophase of mitosis chromatin condenses to form chromosomes and the nucleolus disappears. During prometaphase the nuclear membrane disintegrates. During anaphase of mitosis the sister chromatids separate.
Example Question #21 : Understanding Mitosis
Which of the following is the total number of chromosomes in somatic cells and gametes, respectively?
Somatic cells have 20 chromosomes and gametes have 30
Somatic cells have 23 chromosomes and gametes have 46
Somatic cells have 23 chromosomes and gametes have 23
Somatic cells have 46 chromosomes and gametes have 23
Somatic cells have 46 chromosomes and gametes have 46
Somatic cells have 46 chromosomes and gametes have 23
Somatic cells refer to all cells in the body, with the exception of the reproductive cells. Gametes are the reproductive cells, namely the sperm and egg cells.
Somatic cells each have 46 chromosomes in total, with 23 chromosomes from each parent. Each somatic cell contains 23 homologous pairs and is considered diploid. Gametes have 23 chromosomes in total, one copy from each homologous pair, and are considered haploid. When two gametes fuse to form a zygote, each gamete contributes one copy of each chromosome. This results in a diploid zygote with 46 chromosomes.
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