asexual reproduction
one cell splits into two and no genetic material is exchanged
sexual reproduction
two cells come together and genetic material is exchanged
binary fission
division of a prokaryotic cell into two offspring cells
somatic cell
all body cells except the sex cells
somatic cell ex
skin cells
red blood cells
brain cels
white blood cells
gametes
the sex cell
--the game gamete-egg cell
the male gamete--the sperm cell
fertilization
nucleus of the two gamete cells come together
zygote
fertilized egg
diploid number (represented by 2n)
normal number of chromosomes
-diploid number in humans--46
halpoid number or n
half the normal number of chromosomes
-what cell has n--gametes
gametogenesis
process in which gametes form through meiosis
mitosis
simple cell division, occurs in somatic cells, used for growth and repair
meiosis
cell division in the sex cells
chromatin
mass of unorganized material that contains DNA in non dividing cells and will become chromosomes during cell division
chromosomes
composed of DNA and protein
-main protein on chromosomes-histones
histones
help maintain shape of chromosomes and keep DNA tightly packed
sex chromosomes
determine sex of offspring and may carry other genes for other traits
female sex chromosome
XX
male sex chromosome
XY
autosomes
all other chromosomes
in somatic cells how many autosomes?
44 autosomes and 2 sex chromosomes
in gamete cells how many autosomes
22 autosomes and 1 chromosome
homologus chromosomes
pair of chromosomes that are similar in size and shape and control the same traits
cancer
uncontrollable division of cells
karyotype
picture of chromosomes used to examine for genetic disorders and sex of the offspring