H Biology Cell Division Flashcards
Chromosomes
“Package” of DNA within the nucleus of a cell
Asexual Reproduction
Genetically identical offspring from a single parent, Mitotic Division
Clone
Clones contain identical DNA
Sexual Reproduction
Combination of DNA from two individuals of opposite sex, produces a genetically different offspring, Meiosis
Binary Fission
The process of asexual reproduction by separation of one body into two new bodies (simple cell division)
Chromatin
The complex of the DNA and histone proteins that make up chromosomes (chromosome = histone + DNA)
Sister Chromatids
Identical copies of a chromosome, attached together by a centromere
Centromere
Connects a pair of sister chromatids, Region of a chromosome where a spindle fiber is attached
Mitosis
One cell divides into two daughter cells, essential for growth, repair, and asexual reproduction
Cell Cycle
The series of events that take place during cellular division. Refers to to process of mitosis
Cytokinesis
The division of the cytoplasm, at the end of both mitosis and meiosis
Spindle fibers
Filaments that form during prophase of cell division, which function to separate sister chromatids into daughter cells
Centrosomes
A structure in the cytoplasm of a cell from which microtubules (spindle fibers) originate from
Cleavage Furrow
A valley formed between two separating daughter cells during cell division
Cell Plate
A divider formed between two separating cells, forms In plants.
Somatic Cell
All bodily cells other than sperm and egg cells
Homologous Chromosomes
Chromosomes that are the same size, their loci are in the same location but can very in allele (type of gene- Ex: curly hair vs straight hair)
Locus
The location of a gene on a chromosome
Autosomes
Any chromosome that is not a sex chromosome
Sex Chromosomes
Chromosomes that determine sex (X & Y)
Diploid Cell
A cell that contains two copies of each chromosome (Ex- two long two short)
Haploid Cell
A cell that contains one of each chromosome (Ex- one long one short)
Gametes
Sex/Reproductive Cells, eggs in women and sperm in men (haploid)
Fertilization
The process of combining male and female gametes, the product is a zygote
Zygote
A diploid cell formed by fertilization
Meiosis
Sexual cell division in which a single cell divides twice and forms four daughter cells
Crossing Over
The exchange of DNA between two homologous chromosomes, resulting in the formation of genetically unique DNA
Chiasmata
The process that physically links homologous chromosomes during meiosis, forms by crossover recombination
Recombinant chromosomes
The rearrangement of DNA by breakage and joining of chromosomes, this process forms new alleles
Nondisjunction
When two sister chromatids fails to separate, can occur during metaphase 1/2 and anaphase 1/2
Karyotype
A complete set of an organisms chromosomes
Aneuploidy
An abnormality in the number of someones chromosomes, a result of either a loss or a duplication of a chromosome
Life Cycle
2 pivotal points, meiosis (cuts a cell in half) and fertilization (brings it back)
Germ Cells
Cells in testis of men and ovaries of women, undergo meiosis to produce sperm and egg (one germ cell produces 4 sperm/egg cells)
