BIO 222 Chapter 2: Chromosomes and Reproduction

Bacteria and archaea are prokaryotes. They differ from eukaryotes in that they have no nucleus, a single circular chromosomal genome (usually), and a smaller amount of DNA.

False (B)

<p>Circular structure (C)</p> Signup and view all the answers

<p>To attach to spindle microtubules (D)</p> Signup and view all the answers

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

<p>G1/S checkpoint (A)</p> Signup and view all the answers

<p>Nuclear division and cell division (C)</p> Signup and view all the answers

<p>Anaphase (C)</p> Signup and view all the answers

<p>True (A)</p> Signup and view all the answers

<p>Reduction of the chromosome number by half (A)</p> Signup and view all the answers

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

<p>Contributes to genetic variation in gametes (A)</p> Signup and view all the answers

<p>Separation of sister chromatids (C)</p> Signup and view all the answers

<p>Meiosis produces four daughter cells from each original cell. However, the number of chromosomes in these daughter cells is reduced by half. The newly formed cells from meiosis are also genetically different from one another and from the parental cell.</p> Signup and view all the answers

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

<p>Spermatogenesis is the production of sperm cells in males, while oogenesis is the production of egg cells in females.</p> Signup and view all the answers

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

<p>During anaphase I, shugoshin protects cohesin at the centromeres from the action of separase, preventing the separation of sister chromatids. However, during anaphase II, shugoshin breaks down, and cohesin at the centomeres is cleaved by separase, allowing the sister chromatids to separate.</p> Signup and view all the answers

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

Unicellular organisms lacking membrane-bound organelles. Their DNA is not organized into tightly packed chromosomes. Examples include bacteria and archaea.

Organisms with membrane-bound organelles, including a nucleus containing DNA organized into chromosomes. They can be unicellular or multicellular.

Diploid cells contain two sets of chromosomes, one set from each parent.

Haploid cells contain one set of chromosomes.

The point on a chromosome where spindle microtubules attach during cell division.

The protective ends of linear chromosomes.

The specific locations on DNA where DNA replication begins.

The extended period between cell divisions in the cell cycle, where DNA synthesis and chromosome replication occur.

The phase of the cell cycle where the replicated chromosomes separate and the cytoplasm divides.

The first stage of mitosis where chromosomes condense and the mitotic spindle forms.

The stage of mitosis where the nuclear envelope breaks down and spindle microtubules attach to chromosomes.

The stage of mitosis where chromosomes align at the center of the cell.

The stage of mitosis where sister chromatids separate and move to opposite poles.

The final stage of mitosis where chromosomes reach the poles, the nuclear envelope reforms, and the cytoplasm divides.

The process of dividing the cytoplasm of a cell following mitosis or meiosis.

A cell cycle checkpoint that ensures all conditions are favorable for DNA synthesis.

A cell cycle checkpoint that ensures DNA replication is complete and undamaged before cell division.

The process of cell division that produces two daughter cells genetically identical to the parent cell.

The process of cell division that produces four haploid gametes (sex cells) from one diploid cell.

The fusion of two haploid gametes to form a diploid zygote.

The close pairing of homologous chromosomes during prophase I of meiosis.

The four chromatids of two homologous chromosomes that are closely associated during prophase I of meiosis.

The exchange of genetic information between non-sister chromatids of homologous chromosomes during prophase I of meiosis.

The random alignment of homologous chromosome pairs along the metaphase plate during metaphase I of meiosis.

The separation of homologous chromosome pairs during anaphase I of meiosis.

The process of producing male gametes (sperm cells).

The process of producing female gametes (egg cells).

The protein that holds sister chromatids together during mitosis and meiosis.

A protein that protects centromeric cohesin from degradation during meiosis I.

A diploid cell that undergoes meiosis to produce haploid microspores in plants.

A diploid cell that undergoes meiosis to produce haploid megaspores in plants.