gamete
reproductive cells, sperm or egg
binary fission
form of asexual reproduction, produces identical offspring
gene
a segment of DNA that codes for a protein or RNA molecule
chromosome
DNA and proteins associated with DNA
chromatid
two exact copies of DNA that make up chromosomes
centromere
the point that attaches two chromatids to form a chromosome
homologous chromosome
chromosomes that are similar
diploid
contains 2 sets of chromosomes
haploid
when a cell contains 1 set of chromosomes
zygote
a fertilized egg cell
autosome
chromosomes that are not directly involved in determining gender
sex chromosome
one of the 23 pairs of chromosomes that determine sex
karyotype
a photo of the chromosomes in a dividing cell that shows the chromosomes arranged by size
cell cycle
a repeating sequence of cellular growth and division during the life of an organism
interphase
G1, S, G2; cell grows rapidly; DNA is copied; preparations are made for nucleus to divide
mitosis
the process during cell division in which the nucleus of a cell is divided into two nuclei
cytokinesis
cytoplasm divides
cancer
cells divide uncontrollably
spindle
structures made up of centrioles and microtubules; moves chromosomes
prophase
chromosomes become visible; nuclear envelope dissolves; spindle forms
metaphase
chromosomes line up along equator
anaphase
centromeres divide; chromosomes move towards opposite poles
telophase
nuclear envelope forms at each pole; chromosomes uncoil; spindle dissolves; cytokinesis begins
meiosis
a form of cell division that halves the number of chromosomes when forming reproductive cells
crossing-over
portions of a chromatid on a homologous chromosome are broken and exchanged with another homologous chromosome
independent assortment
random distribution of homologous chromosomes during meiosis
spermatogenesis
sperm being produced in male animals
sperm
male gametes
oogenesis
gametes (egg) is produced
ovum
formed from oogenesis
asexual reproduction
a single parent passes copies of its genes
clone
an offspring produced from asexual reproduction
sexual reproduction
2 parents each form reproductive cells that have half the number of chromosomes
fertilization
results in a diploid zygote
sporophyte
diploid phase that produces spores
gametophyte
haploid phase that produces gametes by mitosis