MEIOSIS Flashcards
What does sexual reproduction produce?
Genetic Variety
what two key processes does sexual reproduction need?
•formation of haploid sex cells called gametes
•fertilization, when the sex cells join to form a zygote
, what are the reproductive organs that make the sex cells? list what they make
-Testes(They make sperm)
-ovaries (make eggs called ova)
ova= more than 1 egg
ovum =1 egg
what does sexual reproduction depend on?
Meiosis
explain meiosis
two-stage cell division where the daughter cells have half the number of chromosomes of the parent cell
-results in formation of gametes or spores
how many chromosomes does a healthy human have?
46
human cells with 46 chromosomes that undergo meiosis will make gametes that each have how many chromosomes?
23
What are humans haploid and diploid number?
haploid number is 23 chromosomes
diploid number is 46 chromosomes
how does fertilization occur?
when haploid sperm cell unites with a haploid egg cell to form a diploid zygote
What is a somatic cell?
every other cell except sex cell
what does haploid mean?
A cell with one set of chromosomes (n). Gametes like sperm and egg cells are haploid
what does diploid mean?
A cell with two sets of chromosomes (2n)
(somatic cells are diploid)
What are homologous chromosomes
Homologous chromosomes carry information for the same genes, we get 1 chromosome from each parent
which homologous chromosomes aren’t similar in size and shape?
the Sex genes (X and Y chromosomes)
How many stages does meiosis involve and how many haploid cells does it make?
it involves 2 stages that make 4 haploid cells
