Biology 2020: Chapter 10 Cell Reproduction Flashcards

Flashcards covering cell division, the eukaryotic cell cycle, the stages of mitosis, DNA compaction, and the basics of sexual reproduction and gametogenesis.

Cell division

The process by which a cell divides to form new cells.

Asexual reproduction

A type of cell division that produces 2 genetically identical cells.

Sexual reproduction

A type of cell division that produces 4 cells containing $\frac{1}{2}$ of the genetic material to make an organism.

Cell cycle

The ordered series of events in the life of a cell that lead to cell division.

G1 phase

The first gap phase of the cell cycle characterized by cell growth where the cell is biochemically active despite no evident change.

S phase

The stage of interphase where DNA synthesis occurs and identical copies of DNA molecules called sister chromatids are joined at the centromere.

G2 phase

The second gap phase where energy is replenished, organelles reproduce, and the cytoskeleton breaks down to prepare for the mitotic phase.

M phase

The phase of the cell cycle consisting of nuclear division (karyokinesis) and cytokinesis.

Mitosis

A form of nuclear division that produces 2 genetically identical nuclei.

Meiosis

A form of nuclear division that produces 4 nuclei containing $\frac{1}{2}$ of the genetic material.

Cytokinesis

The division of the cell into new cells through the physical separation of cytoplasmic components into 2 daughter cells.

Diploid

A cell ($2n$) that contains two complete copies of the entire genome.

Homologues

The name for two versions of the same chromosome, typically one from each biological parent.

Sister chromatids

Two identical copies of one homologue within a cell joined at the centromere prior to division.

Chromosomes

Structures consisting of a single DNA molecule with proteins.

Chromatin

The condensed form of a chromosome found in eukaryotes, composed of DNA and proteins.

Histones

Proteins that group together to help compact DNA.

Nucleosome

The structure formed when DNA is wrapped around histones.

Euchromatin

More loosely compacted chromatin that is considered "active" and more likely to be transcribed.

Heterochromatin

Highly compacted chromatin that is considered "inactive" and typically not transcribed.

Centrosomes

Structures that produce the mitotic spindles required to move chromosomes during cell division.

Centrioles

Structures associated with centrosomes in animal cells that help organize cell division.

Karyokinesis

Also called mitosis, this is the first step of the mitotic phase involving nuclear division.

Prophase

The first stage of mitosis where the nuclear envelope breaks down, organelles migrate to the edges, microtubule spindles form, and sister chromatids coil tighter.

Prometaphase

The mitotic stage where sister chromatids develop kinetochore proteins in the centromere and centrosomes migrate to the poles.

Kinetochore

Proteins developed in the centromere regions that attach sister chromatids to spindle fibers.

Metaphase

The mitotic stage where chromosomes align at the metaphase plate.

Anaphase

The stage of mitosis where chromatids separate and move in opposite directions as the cell elongates.

Telophase

The final stage of mitosis where chromosomes reach opposite poles and decondense, nuclear envelopes form, and spindles disappear.

G1 checkpoint

A control point that checks for genomic damage and ensures energy and cell size reserves are sufficient to enter S phase.

G2 checkpoint

A control point that blocks M phase if protein reserves are low, chromosomes are not fully replicated, or DNA damage is present.

M checkpoint

Also called the spindle checkpoint, this occurs near the end of metaphase to determine if all sister chromatids are correctly attached to spindles.

Haploid

A cell ($1n$) that has only 1 version of its genome.

Gametes

Haploid cells, such as egg and sperm, required for sexual reproduction.

Fertilization

The process of two haploid gametes joining together to form a diploid product.

Zygote

The diploid cell produced by the fertilization of two gametes.