Unit 5a- Meiosis and Sexual Life Cycles Flashcards
Genes
segments of DNA that code for basic units of heredity
What is the two types of Reproduction?
asexual and sexual
Asexual reproduction
produces clones (genetically identitcal)
single parent
little variation in populations - through mutations
fast and energy efficient
Sexual reproduction
meiosis produces gametes
2 parents
lots of variation/diversity
slower and energy consumptive
Mitosis
body cells
somatic
diploid
2n
Meiosis
sex cells
gametes
haploids
n
Homologous chromosomes
includes 1 chromosome from each parent, with the same allele
Autosomes
22 pairs of chromosomes that do not determine sex
Gametes
22 autosomes and 1 sex chromosomes
Karyotype
a picture of an organism’s complete set of chromosome
Fertilization and mieosis
alternate in sexual life cycle
Meiosis is
cell division that reduces the number of chromosomes , creates gametes of 23 chromosomes
Meiosis = Reduction Division
cell divide twice
result 4 daughter cells , each w/ half as many chromosomes as parent cell
Prophase I
crossing over at the chiasmata occurs
homologous chromosomes pair up
Synapsis
homologous chromosomes pair up