Cell Reproduction Terms Part 1 Flashcards
Condensed chromatin structure formed when cells replicate.
Chromosomes
One half of a chromosome. Two sister chromatids are joined by a centromere to form a chromosome.
Chromatid
The long strands that form chromosomes and contain DNA, RNA and various proteins. Found in the nucleus of cells.
Chromatin
One of two chromosomes that are genetically identical and held together at the centromere.
Sister chromatids
One of the different forms of the same gene
Alleles
Governs expression of a trait
Gene
X or Y chromosome; determines genetic sex (Female = XX; Male = XY)
Sex chromosomes
Chromosomes with the same gene sequence
Homologous chromosomes
Cells with two pairs of homologous chromosomes. The ——— number in humans is 46, or 23 pairs.
Diploid cell
Cell with half the number of chromosomes as diploid. Human gametes, or reproductive cells (egg and sperm cells), are ———. (The ——— number of chromosomes in a species is designated as n. In humans, n = 23, and a diploid cell has 2n chromosomes (2n = 46).)
Haploid cell
An individuals complete set of chromosomes.
Karyotype
The cell grows quickly during this phase, making new cell molecules (except DNA).
G1 phase
The DNA in the chromatin replicates to create an identical copy of DNA. These two identical chromosomes, called sister chromatids are joined at the centromere.
S phase
This second growth stage lets the cell rebuild its reserves of energy to prepare for division. As well, the cell manufactures proteins and other molecules to make structures required for division of the nucleus and cell.
G2 phase
Refers to a body cell
Somatic cell
Sex cell (egg or sperm)
Germ cell
Growth phase; includes G1, S phase, and G2
Interphase
It is a continuous process that involves two stages: mitosis and cytokinesis
Division Stage
Division of the cell’s nucleus where the daughter cells receive the exact number of chromosomes and genetic makeup as the parent cell.
Mitosis