Honors Bio - Ms.Das's Cell Cycle/Division Test

Gametes

Sperm and egg that fuse to form a zygote.

Meiosis

A single cell divides twice to produce four haploid gametes.

Gametogenesis in males

Males produce four sperm.

Gametogenesis in females

Females produce one egg and three polar bodies.

Genetic variation mechanisms

Crossing-over, independent assortment, and random fertilization.

Haploid gametes

Needed so that after fertilization, the chromosome number remains constant.

Prophase I of meiosis vs prophase of mitosis

Homologous chromosomes pair up in meiosis but not in mitosis.

Independent assortment

Randomly distributes maternal chromosomes into different gametes.

Crossing-over

The exchange of genetic material between non-sister chromatids.

Human sperm

Are haploid.

Sister chromatids during meiosis I

Do not separate.

Cells produced after meiosis

Four cells are produced.

Metaphase I

Stage of meiosis where homologous chromosomes line up in the center.

Anaphase II

Stage where sister chromatids separate.

Anaphase I

Stage where homologous chromosomes separate.

DNA before cell division

Chromatin condenses into chromosomes.

Phases of mitosis

Prophase, metaphase, anaphase, telophase.

Cytokinesis in animal cells

The cytoplasm divides, forming two cells.

Mitosis vs cytokinesis

Mitosis divides the nucleus; cytokinesis divides the cytoplasm.

X-shaped chromosome

Represents a replicated chromosome before cell division.

Chromosome components

Centriole is NOT part of a chromosome.

Sister chromatids not separate

One daughter cell gets too many chromosomes.

Order of cell division steps

DNA replication → DNA condensation → chromosome alignment → chromatid separation → cytokinesis.

Nuclear envelope breakdown during mitosis

Allows spindle fibers to attach to chromosomes.

Spindle fibers

Fibers that attach to centromeres during mitosis.

Chromosomes during anaphase

Do not begin to uncoil.

Sister chromatids during cytokinesis

Do not line up along the equator.

Mitosis

Results in two daughter cells with identical DNA.

Eukaryotic cell cycle phases

Interphase and M phase.

Phases of interphase

G1, S, G2.

Cell cycle control

Through checkpoints and regulatory proteins.

Cancer and the cell cycle

Cancer cells ignore checkpoints and divide uncontrollably.

Complexity of eukaryotic cell division

Due to multiple chromosomes and a nucleus.

Major steps of eukaryotic cell division

Mitosis and cytokinesis.

Interphase duration

Cells spend most of their lives in interphase.

Phases with twice the normal DNA

S and G2 phases.

Damaged gene for cell cycle regulatory protein

The cell may lose control and divide uncontrollably.

Cell splitting during interphase

A cell does not fully split into two.

G1 checkpoint failure

Cells enter G0.

Cytokinesis in prokaryotes and eukaryotes

Occurs in both.

G2 phase

The interphase phase is where the cell prepares for division.