Ch.11.4 Meiosis Flashcards
Polar body
The small cell created when eggs are being formed
“Specialness” about the formation of eggs
The cell splits unevenly so one cell is big and healthy and that one becomes the fertilized egg
Heredity
The transition of traits from one generation to another
How many chromosomes in a normal cell
46
Locus
The specific location of a gene
Asexual reproduction
An individual passes along copies of all its genes to its offspring
Sexual reproduction
The fusion of two separate parent cells. In sexual reproduction, offspring are produced by the fusion of special reproductive cells formed by each of two parents. Offspring produced by sexual reproduction inherit some of their genetic information from each parent.
Somatic cell
Body cells
Karyotype
A picture of the chromosomes
Homologous chromosomes
The same/marching chromosomes from each parent
They carry the same genes
Sex chromosomes
Th X and Y that determine sex
Autosomes
The chromosomes that aren’t the sex chromosomed
Gamates
The sperm and egg cells
Haploid
A cell with only one set on genes
Zygote
Fertilized egg
Diploid
Cells with 2 sets of DNA
How are gametes produced?
Meiosis
What happens before meiosis
DNA replucation
Prophase 1 / synapsis
The father and mother chromosomes (homologous pairs) come together to form the tetrad
(Kinetachores attach to one side of each chromosome so the whole chromosome is pulled to one side)
Tetrad
The 2 homologous pairs of chromosomes that come together
Chiasmata
Where crossing over takes place
Crossing over
The 2 chromosomes in the tetrad get so close that genes can switch between the two
Recombinant chromosomes
Chromosomes that contain both parents DNA becaus elf crossing over
How is variation among offspring possible?
- crossing over
- independent assortment
- random fertilization
