Cancer and Cell Division

These flashcards cover key terms and definitions related to cancer, cell division, meiosis, and reproduction in both plants and animals.

Cancer

A term used for diseases in which abnormal cells divide without control and can invade nearby tissues.

Mitotic error

A mistake that occurs during cell division, which can lead to uncontrolled cell growth and cancer.

Cell division regulation

Processes that control how and when cells divide, which can become disrupted in cancer.

Zygote

The fertilized egg that results from the union of sperm and egg, which is diploid.

Diploid (2n)

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

Haploid (n)

A cell or organism that has one set of chromosomes, typical of gametes.

Sporophyte

The diploid phase in the life cycle of plants that produces spores.

Gametophyte

The haploid phase in the life cycle of plants that produces gametes.

Meiosis

A type of cell division that reduces the number of chromosomes in the parent cell by half and produces four haploid cells.

Prophase I

The first stage of meiosis where homologous chromosomes pair up and crossing over occurs.

Crossing over

The exchange of genetic material between homologous chromosomes during meiosis.

Chiasmata

The points at which homologous chromosomes exchange genetic material during crossing over.

Cohesin

A protein that holds sister chromatids together and plays a role in the dissolution of the synaptonemal complex.

Synaptonemal complex

A protein structure that forms between homologous chromosomes during prophase I of meiosis.

Bivalent

A pair of homologous chromosomes that are physically connected during meiosis.

Metaphase I

The stage of meiosis where pairs of homologous chromosomes line up at the metaphase plate.

Telophase II

The stage of meiosis II during which the chromatids reach the opposite poles, and the cell divides.

Gametes

Reproductive cells (sperm and egg) that are haploid and fuse during fertilization.

Spermatogenesis

The process of sperm cell development in male animals.

Oogenesis

The process of egg cell development in female animals.

Isogamous

A term describing species that produce morphologically similar gametes.

Heterogamous

A term describing species that produce morphologically different gametes.

Secondary oocyte

The larger haploid cell produced during oogenesis that is released during ovulation.

Polar body

A small haploid cell produced during oogenesis that typically does not develop into an egg.

Ovulation

The release of a mature oocyte from the ovary.

Fertilization

The process where a sperm cell fuses with an egg cell, forming a zygote.

Sporogenesis

The process of producing spores through meiosis in plants.

Life cycle of plants

The alternating generation of diploid sporophytes and haploid gametophytes.

Microspore

A haploid spore that develops into a male gametophyte in plants.

Megaspore

A haploid spore that develops into a female gametophyte in plants.

Acrosome

A cap-like structure on the head of a sperm cell that contains enzymes to help penetrate the egg.

Gametogenesis

The process of forming gametes (sperm and egg) in organisms.

Diploid cell

A cell that contains two complete sets of chromosomes.

Reduced chromosome number

The decrease in chromosome number as a result of meiosis, producing haploid cells.

Genetic variation

Differences in DNA sequences among individuals, often increased through crossing over and independent assortment during meiosis.

Monads

A single chromosome in a haploid cell after meiosis.

Homologous chromosomes

Chromosome pairs, one from each parent, that are similar in shape, size, and genetic content.

Mitosis endpoint

The process results in two genetically identical diploid daughter cells.

Meiosis endpoint

The process that produces four genetically diverse haploid cells.

Gamete fusion

The union of male and female gametes during fertilization.

Equational division

The term that describes the second meiotic division, akin to mitosis, where sister chromatids are separated.

Sister chromatids

Identical copies of a chromosome that are connected by a centromere.

Genetic material exchange

The process of crossing over that leads to genetic diversity among gametes.

Mitosis vs. Meiosis

Mitosis creates identical diploid cells, while meiosis produces unique haploid cells.

Nutrient storage in gametes

Egg cells often store more nutrients compared to sperm cells, which are small and mobile.

Gametophyte complexity

The multicellular structure arising from spores in plants, which leads to gamete production.

Plant vs. Animal Reproduction

Animals produce gametes directly, while plants produce spores that develop into multicellular gametophytes.

Zygotic meiosis

The phase in some organisms where meiosis occurs after fertilization of the zygote.

Haploid (n) number of chromosomes

The number of chromosomes in a gamete after meiosis.