Unit 8: Meiosis and Genetics Flashcards
What is Meiosis?
A type of cell division where 1 body cell divides to make 4 sex cells.
How many cycles of cell division are in meiosis?
2
What are sex cells?
Egg and sperm cells
What are sex cells also called?
Gametes
Where are egg cells made?
Ovaries of a woman
Where are sperm cells made
Testes of a man
What type of cells are body cells?
Diploid cells
What is a diploid cells?
A cell with 2 of each type of chromosome (46)
What type of cells are sex cells?
Haploid cells
What is a haploid cells?
A cell with one of each type of chromosome (23)
If an earthworm haploid number is 18. What is its diploid number of chromosomes?
36
An onions diploid number (2N) is 16 what is its haploid number?
8
What is it called when and egg cell and a sperm cell combine?
Zygote (Fertilized egg cell)
Why do gametes have 1/2 the number of chromosomes?
Because when they combine they will have 46 chromosomes.
What are Homologous chromosomes?
Pairs of chromosomes (1 from mom, 1 from dad)
Do each pair of homologous chromosomes have similar genes?
Yes
What is a Karyotype
Number and appearance of chromosome (shows 23 pairs of homologous chromosomes.
In meiosis how 1 diploid cells turns into how many haploid cells?
4
What happens in interphase of meiosis?
Chromosomes duplicated (double) and becomes visible
What happens in Prophase 1 in meiosis?
Homologous chromosomes pair up they form a tetrad
What is a tetrad?
2 homologous chromosomes (4 sister chromatids)
What happens during crossover?
Homologous chromosomes break apart and exchange genes
Why is crossing over an important proccess?
-It allows you to get some genes from mom and some from dad
-It allows for genetic variation a new combination of genes
