Chapter 7 Cell Cycle and Cell Division

Asexual Reproduction

Type of reproduction resulting in genetically identical daughter cells; variations arise from mutations.

Sexual Reproduction

Reproduction involving the fusion of gametes, leading to genetically diverse offspring.

Mitosis

A type of cell division resulting in two genetically identical daughter cells.

Meiosis

Cell division that reduces chromosome number by half, producing four genetically different haploid cells.

Diploid (2n)

A cell containing two complete sets of chromosomes, one from each parent.

Haploid (n)

A cell containing only one set of chromosomes; gametes are haploid.

Chromosome

A DNA molecule with part or all of the genetic material; organized in eukaryotic cells.

Nondisjunction

Failure of homologous chromosomes or sister chromatids to separate properly during cell division, leading to an abnormal number of chromosomes.

Aneuploidy

An abnormal number of chromosomes in a cell due to nondisjunction, resulting in conditions such as Down syndrome.

Cyclin-dependent kinases (CDKs)

Enzymes that regulate the cell cycle by phosphorylating target proteins when activated by binding to specific cyclins.

Apoptosis

Programmed cell death that occurs as a normal part of growth and development, involving systematic disassembly of cellular components.

Telomeres

The protective ends of chromosomes that shorten with each cell division, limiting the number of divisions a cell can undergo.

Cell Cycle Checkpoints

Control points in the cell cycle where signals regulate progression, ensuring that conditions are favorable for division.

Cytokinesis

The process of cytoplasmic division that separates the two daughter cells after mitosis or meiosis.

Binary Fission

A method of asexual reproduction in prokaryotes where the cell divides into two equal parts.

Gametes

Haploid reproductive cells that fuse during fertilization to form a diploid zygote.

Zygote

The diploid cell formed when two gametes fuse during fertilization.

Somatic Cells

Body cells that are not specialized for reproduction and contain diploid chromosomes.

Chiasmata

Points where homologous chromosomes exchange genetic material during prophase I of meiosis.

Cytokinesis in plant cells

Involves the formation of a cell plate to separate the daughter cells.

Cytokinesis in animal cells

Involves a contractile ring that pinches the cell membrane to separate the daughter cells.

Growth Factors

Signal proteins produced by cells that stimulate cell division and differentiation.

G1 Phase

The first phase of the cell cycle where cells carry out normal functions and growth.

S Phase

The phase of the cell cycle during which DNA is replicated.

G2 Phase

The second gap phase where cells prepare for mitosis.

M Phase

The phase of the cell cycle encompassing mitosis and cytokinesis.

Kinetochores

Protein structures on chromosome centromeres that attach to spindle fibers during cell division.

Centromere

The region of a chromosome where sister chromatids are joined and where kinetochores form.

RNA

Ribonucleic acid, plays various roles in coding, decoding, regulation, and expression of genes.