Meiosis and Mitosis Lecture Notes Review

Comprehensive vocabulary flashcards covering the concepts of mitosis, meiosis, and sexual/asexual reproduction as described in the lecture notes.

Sexual reproduction

A process where genetic information from two parent cells is passed on to an offspring to increase genetic diversity.

Gametes

Specialized cells used for reproduction; female gametes are called eggs and male gametes are called sperm.

Fertilization

The process in which gametes from two parents combine to form a new cell.

Zygote

The first diploid body cell of a new organism formed during fertilization.

Embryo

The stage of development reached as a zygote undergoes repeated mitosis and cell division.

Diploid ($2n$)

A cell that has two sets or pairs of chromosomes; human body cells are diploid and contain $46$ chromosomes.

Haploid ($n$)

A cell that has only one set of chromosomes; human gametes are haploid and contain $23$ chromosomes.

Meiosis

The process of cell division that ensures each gamete is haploid, producing cells with half the number of chromosomes as body cells.

Homologous chromosomes

A pair of matching chromosomes, one from each parent, found in a diploid cell.

Meiosis I

The first division of meiosis which starts with one diploid cell and finishes with two haploid cells.

Meiosis II

The second division of meiosis which starts with two haploid cells and ends with four haploid cells.

Crossing over

An event in Prophase I where chromatids of homologous chromosome pairs exchange DNA segments to increase genetic variation.

Independent Assortment

The process where homologous pairs of chromosomes separate independently, creating many different combinations in the daughter cells.

Mitosis

A type of cell division resulting in two genetically identical daughter cells with the same number of chromosomes as the parent cell.

Interphase

The phase of the cell cycle where a cell spends most of its time performing activities, growing, and replicating DNA.

Chromatin

The uncoiled form of DNA found in the nucleus during interphase.

Prophase

The first stage of mitosis where the nuclear membrane breaks apart, chromatin condenses into chromosomes, and the spindle forms.

Chromatids

Two identical copies of a duplicated chromosome, often appearing in an X-shape.

Metaphase

The stage of mitosis where chromosomes line up in the middle of the cell along the equator and attach to spindle fibers.

Anaphase

The stage of mitosis where chromatids are pulled apart by the spindle and move to opposite sides of the cell.

Telophase

The final stage of mitosis where two nuclei are formed, chromosomes uncoil, and the nuclear membrane reappears.

Cytokinesis

The process of dividing the cytoplasm and organelles between two new daughter cells.

Binary fission

A form of asexual reproduction used by bacteria and amoeba where a parent cell splits into two identical individuals.

Budding

A form of asexual reproduction used by organisms like yeasts where a new individual grows from the parent.

Spores

A method used by molds for asexual reproduction.

$G_1$ phase

The first part of interphase where cellular contents, excluding the chromosomes, are duplicated.

$S$ phase

The portion of interphase where each of the $46$ chromosomes is duplicated by the cell.

$G_2$ phase

The part of interphase where the cell double-checks the duplicated chromosomes for errors and makes needed repairs.