Chapter 13 - Meiosis Flashcards
Differences between members of the same species
Variation
Transmission of traits from one generation to the next
Heredity
Scientific study of heredity and hereditary variation
Genetics
Discrete unit of hereditary information consisting of a specific nucleotide sequence in DNA
Genes
A haploid reproductive cell such as an egg or a sperm. They unite during sexual reproduction to produce a diploid zygote
Gametes
Any cell in a multicellular organism except a sperm or an egg or their precursor
Somatic cell
A specific place along the length of a chromosome where a given gene is located
Locus
The generation of offspring from a single parent that occurs without the fusion of gametes. In most cases, offspring are genetically identical to the parent
Asexual reproduction
Reproduction in which two parents give rise to offspring that have unique combinations of genes inherited from the gametes of the parents
Sexual reproduction
A group of genetically identical individuals
Clone
Generation-to-generation sequence of stages in the reproductive history of an organism
Life cycle
A display of chromosome pairs of a cell arranged by size and shape
Karotype
A pair of chromosomes of the same length, centromere position, and staining pattern that possess genes for the same characters at corresponding loci. One of the chromosomes is inherited from the mother and one from the father.
Homologous chromosomes
Chromosome responsible for determining the sex of an individual
Sex chromosomes
Chromosome not involved in sex determination
Autosomes
Cell containing two sets of chromosomes (2n) one from each parent
Diploid cells
Cell with one set of chromosomes (n)
Haploid cells
Union of gametes culminating in fusion of their nuclei
Fertilization
Diploid product of the union of haploid gametes during fertilization; a fertilized egg
Zygote
A modified type of cell division in sexually reproducing organisms consisting of two rounds of cell division but only one round of DNA replication. It results in cells with half the number of chromosome sets as the original cell
Meiosis
A life cycle in which there is both a multicellular diploid form, the sporophyte, and a multicellular haploid form, the gametophyte; characteristic of plants and some algae
Alternation of generations
Homologous chromosomes separate
Meiosis 1
Sister chromatids separate
Meiosis 2
The reciprocal exchange of genetic material between non-sister chromatids during prophase 1 of meiosis
Crossing over
X-shaped, microscopic region where homologous non-sister chromatids have exchanged genetic material through crossing over during meiosis, the two homologous chromosomes remaining associated due to sister chromatid cohesion
Chiasmata (chiasma)
Zipper-like structure that physically connects homologous chromosomes during prophase 1
Synaptonemal complex
Pairing and physical connection of duplicated homologous chromosomes during prophase 1 of meiosis
Synopsis
A chromosome created when crossing over combines DNA from two parents into a single chromosome
Recombinant chromosomes
