Cell Division and Gametogenesis LAB

Flashcards covering key vocabulary related to oogenesis, spermatogenesis, meiosis, mitosis, and general cell division processes in mammals and plants.

Oogenesis

The process that produces one large nutrient-rich egg per cycle in the ovaries.

Primary oocyte

An oogonium that has begun meiosis but stopped before metaphase I, remaining paused until puberty.

Secondary oocyte

The cell produced after Meiosis I in oogenesis, along with a first polar body. It can be fertilized.

Polar body

Small, discarded cells formed during oogenesis due to unequal cytokinesis.

Follicle (primary, mature)

Capsules in the ovary that contain and protect oocytes during development.

Ovulation

The process where a mature follicle ruptures and releases the secondary oocyte from the ovary.

Corpus luteum

The ruptured follicle that remains in the ovary after ovulation, changing into a hormone factory supporting early pregnancy.

Spermatogenesis

The process that produces many small, functional sperm in the testes.

Seminiferous tubules

Tiny coiled tubes inside the testes where spermatogenesis occurs and sperm is produced.

Spermatogonia

Cells in the outermost layer of the germinal epithelium of the testes that give rise to more spermatogonia and primary spermatocytes.

Primary spermatocyte

Large, round cells that begin meiosis in spermatogenesis.

Spermatid

Small cells produced by Meiosis II in spermatogenesis, which mature into spermatozoa.

Spermatozoa

Mature sperm cells with long, tail-like flagella.

Sertoli (nurse) cells

Cells that nourish spermatids as they mature into spermatozoa.

Gametogenesis

The entire process from a 2n cell to a gamete.

Ovum

A mature female gamete (egg).

Zygote

A cell formed when an ovum is fertilized by a spermatozoan.

Meiosis

A specialized cell division that produces haploid (n) cells, such as gametes, from diploid (2n) cells.

Gamet

A haploid cell (n) that fuses with another gamete during sexual reproduction to form a new diploid cell.

Diploid (2n)

A cell or organism having two sets of chromosomes, one from each parent.

Haploid (n)

A cell or organism having a single set of unpaired chromosomes.

Meiosis I

The first division in meiosis, where homologous chromosomes separate, resulting in two haploid cells with duplicated chromosomes.

Meiosis II

The second division in meiosis, where sister chromatids separate, resulting in four haploid cells.

Homologous chromosomes

Pairs of chromosomes that condense next to each other during prophase I of meiosis, where crossing over occurs.

Crossing over

The exchange of segments of DNA between homologous chromosomes during prophase I of meiosis, increasing genetic variation.

Mitotic cell division

The process in eukaryotic cells that produces two daughter cells nearly identical to the parent cell, responsible for reproduction in unicellular eukaryotes and for growth and tissue repair in multicellular eukaryotes.

Cell cycle

The continuous process that actively dividing eukaryotic cells go through, including interphase and the mitotic phase.

Interphase

The period during which a mitotically active cell spends most of its time, preparing for cell division.

G1 (Gap 1)

The first period of interphase, during which the cell builds proteins and grows larger.

S (Synthesis of DNA)

The period of interphase during which the cell continues to grow and copies its nuclear DNA.

G2 (Gap 2)

The last period of interphase, during which the cell continues to grow as final preparations are made for cell division.

Mitosis

The process of nuclear division within the mitotic phase, ensuring daughter cells receive complete genetic information.

Cytokinesis

The division of the entire cell, which typically overlaps with mitosis.

Chromosome

Condensed chromatin, consisting of a double-stranded DNA molecule with associated proteins, appearing 'X' shaped when duplicated.

Chromatid

One of the two identical copies of DNA that make up a duplicated chromosome, joined at the centromere.

Centromere

The point of attachment between two sister chromatids on a duplicated chromosome.

Prophase (Mitosis)

Phase where chromosomes condense and become visible, the nucleolus disappears, and the spindle starts to form.

Prometaphase (Mitosis)

Phase where the nuclear envelope breaks up, and the spindle attaches to centromeres.

Metaphase (Mitosis)

Phase where chromosomes line up along the middle of the cell (metaphase plate) due to spindle pulling.

Anaphase (Mitosis)

Phase where chromatids break free of each other (now considered chromosomes) and are pulled to opposite ends of the cell.

Telophase (Mitosis)

Phase where the spindle disappears, chromosomes disperse, nucleoli and nuclear envelopes reform, and the cell begins to divide.

Cleavage furrow

The pinching in of an animal cell during telophase and cytokinesis.

Cell plate

A new cell wall that begins to form during telophase in plant mitosis.

Binary fission

A simple process of cell division in prokaryotes where a single cell splits into two nearly identical 'daughter' cells.