Meiosis Flashcards
Meiosis
Cell division in which haploid cells are produced from diploid cells
Haploid
2n
Diploid
n
What does meiosis produce?
eggs and sperm(gametes) cells
Meiosis is the primary mechanism that helps produce and maintain…
genetic variability
What does meiosis result in?
4 daughter cells
Genetic diversity can help a population…
survive an environmental challenge
What phase does replication occur in?
s phase
Homologous chromosomes
2 copies of each chromosome
Alleles
alternate forms of a gene
How many divisions does meiosis have?
2= meiosis 1 and meiosis 2
Meiosis 1=
the reduction division
- reduces # of chromosomes from 46 to 23
- produces 2 cells
Meiosis 2=
the equational division
- produces 4 cells from the two produced in meiosis 1
Each division consists of these phases:
Prophase, metaphase, anaphase and telophase
Mendel’s Law of Segregation(begin meiosis 1)
At the end of meiosis each gamete carries one copy of each allele
Crossing over
Synapsed chromosomes separate but remain attached at a few points
Crossing over helps create…
genetic diversity- new combinations of genes are formed
When does crossing over happen?
Metaphase 1
Mendel’s second law: Independent Assortment
Homologous pairs are separated into daughter cells during meiosis (Look at pictures drawn from SI/ PowerPoint)
What causes independent assortment?
Random alignment of chromosomes
Is independent assortment 2n or n?
2n
Meiosis 2 result…
4 haploid cells
Know Meiosis drawing
in slides or notes
Spermatogenesis
production and development of mature sperm cells
