IS 4A Sexual Reproduction/Chromosomes, Meiosis, and Mutations Study Notes

Reproduction Types

Comparison between sexual and asexual reproduction and their contributions to genetic diversity.

Zygote

The initial cell formed when two gametes merge during fertilization.

Gamete

Reproductive cells (sperm and egg) involved in sexual reproduction.

Chromosome Structure

Anatomy includes the centromere, sister chromatids, and replicated chromosomes.

Ploidy

Refers to the number of sets of chromosomes in a cell, e.g., haploid (n) or diploid (2n).

Meiosis

A type of cell division that reduces the chromosome number by half, producing gametes.

Crossing Over

The exchange of genetic material between homologous chromosomes during meiosis that increases genetic variability.

Nondisjunction

A failure of chromosomes to separate properly during cell division, leading to chromosomal mutations.

Karyotype

A laboratory technique that produces an image of an individual's chromosomes, used to detect chromosomal abnormalities.

Trisomy

A genetic condition in which an individual has three copies of a chromosome instead of the usual two, e.g., Down syndrome.

Sexual Reproduction

A reproductive process that involves the combination of genetic material from two parents, contributing to genetic diversity.

Asexual Reproduction

A reproductive process that involves a single organism producing offspring genetically identical to itself.

Zygote

The fertilized egg formed by the union of a sperm cell and an egg cell.

Gamete

A reproductive cell (sperm or egg) that carries genetic information to the next generation.

Chromosome

A structure composed of DNA and proteins that carries genetic information.

Ploidy

The number of sets of chromosomes in a cell, typically referred to as haploid (n) or diploid (2n).

Meiosis

A type of cell division that produces gametes with half the number of chromosome sets, creating genetic variation.

Mitosis

A type of cell division that results in two genetically identical daughter cells, used for growth and repair.

Nondisjunction

The failure of homologous chromosomes or sister chromatids to separate properly during cell division, leading to chromosomal mutations.

Karyotype

A laboratory technique that produces an image of an individual's chromosomes, often used to detect chromosomal aberrations.

Trisomy

A genetic disorder caused by the presence of an extra chromosome, such as Down syndrome.

Monosomy

A genetic condition where a chromosome is missing from a normal diploid set, such as Turner's syndrome.

Reproduction Types

Comparison between sexual and asexual reproduction and their contributions to genetic diversity.

Zygote

A fertilized egg that results from the union of gametes.

Gamete

A reproductive cell that contains half the genetic material of an organism, such as sperm or egg.

Chromosome Anatomy

The structure of a chromosome, including the centromere, sister chromatids, and replicated chromosomes.

Ploidy

The number of sets of chromosomes in a cell, including haploid (n) and diploid (2n) states.

Meiosis

A type of cell division that reduces the chromosome number by half, producing four haploid cells.

Genetic Variation

Diversity in gene frequencies, caused by mechanisms like crossing over and independent assortment during meiosis.

Mutational Classes

Various types of mutations including Duplicate, Translocation, and Inversion.

Nondisjunction

The failure of homologous chromosomes to separate properly during cell division, leading to chromosomal mutations.

Karyotype

A visual representation of an individual's chromosomes, used to detect chromosomal disorders and gender.

Trisomy

A genetic condition where an individual has three copies of a particular chromosome, such as in Down syndrome.

Monosomy

A genetic condition involving the presence of only one copy of a chromosome instead of the usual two, as seen in Turner's syndrome.