Chapter 11: Meiosis and Sexual Reproduction

These flashcards cover the key vocabulary and concepts related to mitosis and meiosis, essential for understanding cell division and reproduction.

Mitosis

A type of cell division responsible for asexual reproduction and tissue growth, resulting in two genetically identical daughter cells.

Meiosis

A specialized type of cell division that reduces the chromosome number by half, producing four genetically diverse haploid cells known as gametes.

Somatic Cells

Body cells that are diploid and undergo mitosis for growth and repair.

Germ Cells

Cells that are diploid and undergo meiosis to produce haploid gametes for sexual reproduction.

Diploid

A cell containing two complete sets of chromosomes, one from each parent, denoted as 2n.

Haploid

A cell containing one complete set of chromosomes, denoted as n.

Gametes

Haploid reproductive cells, such as sperm and egg cells, produced through meiosis.

Crossing Over

The process during meiosis where homologous chromosomes exchange segments, increasing genetic variation.

Independent Assortment

The random distribution of homologous chromosome pairs during meiosis, contributing to genetic diversity.

Prophase

The first stage of cell division where chromosomes condense and become visible.

Metaphase

The stage where chromosomes line up along the cell's equatorial plane before they are separated.

Anaphase

The stage where sister chromatids or homologous chromosomes are pulled apart to opposite ends of the cell.

Telophase

The final stage of cell division where chromosomes de-condense and two new nuclei form.

Interphase

The phase of the cell cycle where the cell prepares for division, involving DNA replication and cell growth.

Cytokinesis

The process that follows telophase, where the cytoplasm divides, resulting in two separate cells.

Synaptonemal Complex

A protein structure that forms between homologous chromosomes during meiosis, facilitating crossing over.

Tetrad

A structure formed during meiosis consisting of a pair of homologous chromosomes, each consisting of two sister chromatids.

Chiasmata

The points of contact between non-sister chromatids of homologous chromosomes during meiosis where crossing over occurs.

Recombinant Chromatids

Sister chromatids that have undergone crossing over, resulting in a new combination of genetic material.

Non-Recombinant Chromatids

Sister chromatids that have not undergone crossing over and remain unchanged.

Reduction Division

A type of cell division, such as meiosis, that reduces the chromosome number by half.

Fertilization

The fusion of haploid gametes to restore the diploid state in a zygote.

Diploid Dominant Life Cycle

A life cycle in which the diploid stage is the prominent form, as seen in most animals.

Haploid Dominant Life Cycle

A life cycle where the haploid stage is the dominant form, as observed in fungi and algae.

Alternation of Generations

A reproductive cycle where an organism alternates between haploid and diploid multicellular stages.

Asexual Reproduction

Reproduction that does not involve the fusion of gametes, often producing clones of the parent organism.

Sexual Reproduction

Reproduction that involves the fusion of gametes, resulting in genetic variation among offspring.

Genetic Variation

The diversity in gene frequencies within a population, often resulting from recombination and independent assortment.

S Phase

The phase of interphase during which DNA is replicated to produce sister chromatids.

Kinetochore

A protein structure on the centromere where spindle fibers attach during cell division.

Sporophyte

The diploid phase in plants and certain algae that produces haploid spores through meiosis.

Gametophyte

The haploid phase in plants that produces gametes through mitosis.

Mycelium

The vegetative part of a fungus, consisting of a mass of branching, thread-like hyphae.

Hyphae

The long, thread-like structures that make up the body of a fungus.

G1 Phase

The first gap phase of interphase where the cell grows and prepares for DNA replication.