Genetics Chapters 1 and 2 Vocabulary Flashcards

Vocabulary flashcards covering key terms and concepts from Chapters 1 and 2, including cellular organization, cell cycle stages, mitosis, meiosis, cohesin dynamics, and animal and plant gametogenesis.

Bioreactor / Fermentation vessel

A stainless-steel tank used to grow microorganisms (such as bacteria or yeast) or mammalian cells under carefully controlled conditions.

Prokaryote

A unicellular organism lacking membrane-bound organelles and a nucleus, with DNA that does not exist in a highly ordered and packed arrangement.

Eukaryote

A unicellular or multicellular organism containing membrane-bound organelles and genetic material enclosed within a nuclear envelope to form a nucleus.

Virus

A structure that is neither prokaryotic nor eukaryotic, consisting of an outer protein coat surrounding a piece of nucleic acid.

Diploid

Refers to cells carrying two sets of genetic information ($2n$).

Haploid

Refers to cells carrying a single set of genetic information ($1n$).

Centromere

The constricted region of a chromosome where kinetochores form and spindle microtubules attach.

Telomeres

The stable ends or tips of a linear chromosome.

Origin of replication

The specific site on a chromosome where DNA synthesis begins.

Interphase

An extended period between cell divisions in the cell cycle during which cell growth, DNA synthesis, and chromosome replication take place.

G0 phase

A stable, nondividing state of variable length that cells may enter from the $G_1$ phase.

G1 phase

The stage of interphase in which the cell grows and synthesizes proteins necessary for cell division before passing the $G_1/S$ checkpoint.

S phase

The stage of interphase during which DNA synthesis and chromosome duplication occur.

G2 phase

The stage of interphase involving biochemical preparation for cell division before passing the $G_2/M$ checkpoint.

Mitosis

The nuclear division process in M phase that separates sister chromatids to produce two genetically identical daughter cells.

Cytokinesis

The process during M phase in which the cytoplasm divides to separate a cell into two newly formed cells.

Prophase

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

Prometaphase

The stage of mitosis in which the nuclear membrane disintegrates and spindle microtubules attach to chromatids.

Metaphase

The stage of mitosis where individual chromosomes align along the metaphase plate.

Anaphase

The stage of mitosis in which sister chromatids separate and migrate toward opposite spindle poles as daughter chromosomes.

Telophase

The stage of mitosis where chromosomes arrive at spindle poles, the nuclear membrane re-forms, and condensed chromosomes relax.

Meiosis

The division process that produces haploid gametes through two rounds of division (reduction division followed by equational division).

Synapsis

The close pairing of homologous chromosomes that takes place during prophase I of meiosis.

Tetrad

A structure consisting of four closely associated sister chromatids belonging to a pair of synapsed homologous chromosomes.

Crossing over

The exchange of genetic material between nonsister chromatids during prophase I, generating genetic variation in newly formed gametes.

Interkinesis

The period between meiosis I and meiosis II where the nuclear membrane re-forms and chromosomes relax in some cells, without DNA synthesis taking place.

Cohesin

A protein that holds sister chromatids together and plays a critical role in chromosome behavior during mitosis and meiosis.

Shugoshin

A protein that protects cohesin at the centromeres during anaphase I of meiosis, preventing sister chromatids from separating until anaphase II.

Spermatogenesis

Male gamete production in animals that produces four haploid spermatids from each primary spermatocyte.

Oogenesis

Female gamete production in animals that results in a single large haploid ovum and polar bodies from a primary oocyte.

Microsporogenesis

Meiosis in the stamens of plants that produces four haploid microspores from a diploid microsporocyte.

Megasporogenesis

Meiosis in the ovaries of plants that produces haploid megaspores from a diploid megasporocyte.

Sporophyte

The multicellular diploid ($2n$) plant structure that produces haploid spores through meiosis.

Gametophyte

The multicellular haploid ($1n$) plant structure that produces haploid gametes through mitosis.

Double fertilization

A plant fertilization mechanism where one sperm cell fertilizes the egg cell to form a diploid ($2n$) zygote, and another sperm cell fuses with two polar nuclei to form triploid ($3n$) endosperm.