Unit 6 Lecture Flashcards
(201 cards)
Define mitosis
For growth and repair, turning a diploid cell into two identical diploid cells
How many pairs of chromosomes do we have
23
Define meiosis
Production of gametes, one diploid cell produces 4 diploid s at a time
Where does meiosis occur?
Happen in the ovaries or testes
Define dimorphic
Meaning two sexes
What do male and female gonads produce?
Male gonads = testes = sperm
Female gonads = ovaries = eggs
What causes the production of gametes?
Hormones
Where does sex cell production occur?
In útero
How many chromosomes do diploid cell have?
46 chromosomes
How many chromosomes did haploid cells have?
23 chromosomes
What are oogonia
Germ cells for females
What are spermatogonia
Germ cells for males
Get unit two notes for mitosis
What is happening during prophase 1?
The chromosomes from mom and dad get close and perform a cross over to increase genetic diversity
What is primary gamete
Duplicated Diploid cells with 46 chromosomes
What is secondary gamete
Haploid cells with 23 chromosomes and need of one more round of duplication
What is final stage gamete?
A Haploid cell with 23 chromosomes that have a single copy of each chromosome(chromatids
How many sperm are produced from a spermatocyte
1 spermatocyte = 4 sperm
What is the timing for males gametogenesis
Before birth immature lots of speratogonia are produced through mitosis . At birth production of sperm is quiescent
At puberty spermatogenesis begins again
What is the timing for gametogeneis for females?
Before birth they complete mitotic divisions to create all primary procures (~ 500,000 at birth)
Primary procures go quiescent after duplicating chromosomes
At puberty 1 primary procure is chosen for maturation and go through meiosis 1.
Produces a secondary oocyte and first polar body
At 2 nd neurotic division begins where the secondary oocyte stops at the fallopian tube and wait for sperm.
Ovulation occurs
If fertilization occurs one set of chromatids combine with a sperm genome and other is casta away as the 2nd polar bodyv
Define monozygotic twins
Aka identical twins have identical DNA , fertilized by one egg.
Where the zygote splits into two
Define dizygotic twins
Like leia and Luke Aka fraternal twins have different DNA , two separate eggs produced during one ovarian cycle and ultimately fertilized by genetically different sperm
Define nondisjunction
When a gamete end with more or less than 23 chromosomes
What is klinefelters syndrome
Chromosomes in male are XXY causing problems with small testicles, ⬇️ fertility