Biology Meiosis Chapter Quiz

<p>6 (B)</p> Signup and view all the answers

<p>Mitosis results in daughter cells with the same number of chromosomes as the parent cell, while meiosis results in daughter cells with half the number of chromosomes. (C)</p> Signup and view all the answers

<p>One daughter cell would have an extra copy of chromosome 21 (trisomy 21), and the other would be missing a copy (monosomy 21). (D)</p> Signup and view all the answers

<p>The condensation of chromatin to form visible chromosomes. (D)</p> Signup and view all the answers

<p>Human somatic cell: 46 chromosomes (2n) (D)</p> Signup and view all the answers

<p>The chromosome number is halved. (D)</p> Signup and view all the answers

<p>12 (D)</p> Signup and view all the answers

<p>Initiating the pre-replication complex to allow one round of DNA replication and preventing further rounds. (D)</p> Signup and view all the answers

<p>By activating proteins in the nuclear envelope, leading to its disintegration, and promoting chromosome condensation. (D)</p> Signup and view all the answers

<p>The breakdown of the nuclear envelope. (D)</p> Signup and view all the answers

<p>The removal of phosphate groups by Cdc25 phosphatase. (C)</p> Signup and view all the answers

<p>By indirectly activating more MPF complexes, creating a positive-feedback loop. (C)</p> Signup and view all the answers

<p>Cyclin is targeted for degradation by the proteasome. (B)</p> Signup and view all the answers

<p>It promotes transcription of the p21 gene, which inhibits G1/S-Cdk and S-Cdk complexes. (C)</p> Signup and view all the answers

<p>It cleaves cohesins, allowing sister chromatids to separate. (B)</p> Signup and view all the answers

<p>Release of active separase. (A)</p> Signup and view all the answers

<p>The degradation of the MPF complex by ubiquitination via the APC/C. (D)</p> Signup and view all the answers

<p>By binding to and inhibiting the activity of Cdk4 and Cdk6 complexes. (D)</p> Signup and view all the answers

<p>It determines whether a cell enters a new cycle or goes into a resting phase, by binding to E-Cdk2 and A-Cdk2 complexes. (C)</p> Signup and view all the answers

<p>When it is damaged, infected, or laden with mutations, to maintain tissue homeostasis. (D)</p> Signup and view all the answers

<p>Necrosis is a passive process induced by external factors, often leading to inflammation, while apoptosis is an active, programmed process. (A)</p> Signup and view all the answers

<p>Swelling of the cell and leakage of its contents into the extracellular space, triggering an inflammatory response. (A)</p> Signup and view all the answers

<p>Chiasmata shift toward the ends of the chromosomes. (D)</p> Signup and view all the answers

<p>The separation of homologous chromosomes. (B)</p> Signup and view all the answers

<p>It facilitates gene expression and cellular activity. (D)</p> Signup and view all the answers

<p>Meiosis II starts with haploid cells, whereas mitosis starts with diploid or haploid cells. (C)</p> Signup and view all the answers

<p>Each sister chromatid is attached to spindle fibers from opposite poles. (A)</p> Signup and view all the answers

<p>Sister chromatids are separated and become daughter chromosomes. (B)</p> Signup and view all the answers

<p>To ensure the correct sequence of cell cycle events and prevent errors. (C)</p> Signup and view all the answers

<p>Integrity of replicated DNA and presence of replication forks. (D)</p> Signup and view all the answers

<p>By cyclically activating and inhibiting proteins and protein complexes. (A)</p> Signup and view all the answers

<p>The S checkpoint will halt the cell cycle to allow for DNA repair. (C)</p> Signup and view all the answers

Stage in Prophase I where chromatin condenses into chromosomes; each has two sister chromatids.

Stage in Prophase I where homologous chromosomes pair to form bivalents/tetrads and the synaptonemal complex forms.

Stage in Prophase I where chromosomes condense further and crossing-over occurs at chiasmata between non-sister chromatids.

Process where homologous recombination occurs, exchanging DNA segments between non-sister chromatids during Pachytene.

Stage in Prophase I where crossing-over finishes and homologous chromosomes begin to separate, connected by chiasma.

Cells containing a double set of chromosomes, denoted as 2n.

Cells containing a single set of chromosomes, denoted as 1n.

A type of cell division where daughter cells receive the same number of chromosomes as the parent.

A type of cell division where daughter cells receive half the number of chromosomes.

A series of processes in eukaryotic cells that lead to cell division.

A complex that activates DNA replication at the end of G1 phase and transitions to S phase.

The phase where DNA is replicated once, allowing transition to G2 phase.

The phase where cyclin A binds Cdk1 to prepare the cell for M phase, and cyclin B is inactive.

The cyclin B-Cdk1 complex that controls mitosis and activates key mitotic processes.

Activated MPF stimulates more MPF activation, enhancing the process.

Anaphase-promoting complex/cyclosome triggers sister chromatid separation and MPF degradation.

A proteolytic enzyme that destroys cohesins, allowing sister chromatids to separate during anaphase.

Proteins that hold sister chromatids together until separated by active separase.

A protein that regulates the cell cycle and can induce arrest or apoptosis in response to DNA damage.

A cyclin-dependent kinase inhibitor produced by activated p53 to halt the cell cycle in G1 phase.

Proteins that regulate cell cycle progression by inhibiting cyclin-CDK complexes.

A subclass of CDKI that inhibit Cdk1, Cdk2, Cdk4, and Cdk6; includes p21, p27, and p57.

A subclass of CDKI that specifically inhibits Cdk4 and Cdk6; examples include p15, p16, p18, and p19.

Process of programmed cell death that is energy-dependent and gene-activated, removing damaged cells.

A passive form of cell death affecting groups of cells, often due to external damage, resulting in inflammation.

Final stage of prophase I in meiosis where chromosomes condense and become visible.

Bivalents align at the equatorial plane, with spindle fibers attaching to one chromatid.

Homologous chromosomes separate and move toward cell poles.

Two daughter cells are formed with a haploid set of chromosomes; cell division occurs.

Follows meiosis I without an S phase, resulting in four haploid gametes from two daughter cells.

Chromatin condenses, nuclear envelope disappears and spindle re-forms in two daughter cells.

Sister chromatids separate and move to opposite poles, becoming daughter chromosomes.

Four haploid daughter nuclei form; cytokinesis follows.

Stages that ensure conditions are right for cell division; decision points for continuing the cycle.

Checks DNA for damage and verifies replication forks during S phase.