Cell division (meiosis) Flashcards
2 goals of meiosis
- Make cells for sexual reproduction
- Create genetic variation
What happens in fertilization
egg and sperm come together to make a zygote (a fertilized egg)
What are gametes
Sex cells, Sperm and eggs
Whats a zygote
a fertilized egg
How do you get genetic variation
mix up moms and dads genes
How many rounds of PMAT does meiosis go through
2
When are chromosomes duplicated (before or after meiosis)
Before
Whats meiosis l
homologs are seprated
Meiosis ll
Sister chromatids are separated
What is maternal chromosome
Moms chromosome in offspring
Whats paternal chromosome
Dads chromosome in offspring
Are body cells diploid or haploid
Diploid
Whats diploid
2 copies of each chromosome
How many pairs of homologous chromosomes do we have.
23
How many chromosomes do you get from mom vs dad
Each pair has 1 from each
What are gametes
sex cells
Ploidy is —-
the number of complete sets of chromosomes
How many different types of chromosomes do humans have
23
Sperm and egg are (diploid or haploid) cells
haploid
Whats haploid
there is only one of each type (not repeated)
Does more chromosomes mean smarter
No
Whats a Karyotype
used to detect chromosomal genetic disorders, which occur when a non- dis-junction occurs
What chromosome numbers are autosomes
1-22
What number chromsome is the sex chromosome
23
XX is
Female
XY is
male
Whats a non disjunction
chromosomes dont separate correctly in meiosis
Whats monosomy
only one copy of each chromosome
Trisomy
three copies of each chromosome
Whats crossing over
Homologous chromosomes switch genes during the first prophase This produces unique chromosomes.
Whats independent assortment
Chromosomes can line up in various ways during metaphase so an individual can produce many combinations of homologous chromosomes
Oogenesis
production of eggs or ova, makes 1 functional egg and 3 polar bodies (non-functional)
Spermatogenesis
production of sperm, creates 4 functional sperm
One advantage of meiosis
new gene combos and genetic variation which helps with natural selection
During the G1 phase of the cell cycle what happens
The cell grows
What is the name of the proteins that help chromatin coil up into chromosomes?
Histones
Somatic cells are also known as
Body cells
Due to nonfunction gametes could loose or gain genes/chromosomes?
Both
Independent assortment refers to
The way chromosomes line up in meiosis l
