12.4 Flashcards
The offspring of two parents obtains a single copy of every gene
from each parent.
True
gamete
an organism’s reproductive cells
gametes must have
one complete set of genes
Genes are located at specific positions on…
Chromosomes
Homologous
A pair of corresponding chromosomes is homozygous
One member of each homologous chromosome pair comes from
each…
gene
A cell that contains both sets of homologous chromosomes is
diploid=2
The gametes of sexually reproducing organisms are
haploid=1/2
Mitosis
first
prophase 1
homologous chromosomes pair up and exchange fragments (crossing over)
metaphase 1
homologues pairs line up at metaphase plate
anaphase 1
homologous separate to opposite ends of the cell (sister chromatids stay together)
telophase 1
newly formed cells are haploid (because they split into 1/2)
CHROMOSOMES HAVE NON-IDENTICAL SISTER CHROMATIDS
miosis (mitosis 2)
second
prophase 2
chromosomes condense
metaphase 2
chromosomes line up at metaphase plate
anaphase 2
sister chromatids separate to opposite ends of the cells
telophase 2
newly form gametes are haploids (each chromosome has just one chromatid)
cross over
exchange of two homoeologous
when doss cross over happen
prophase 1
what happens after cross over
genetic diversity
chromosome number doesn’t change in
mitosis
chromosome number is split in half in
miosis
linked genes??
from sharing chromosomes (genes sharing spaces clump together to form traits that go with one another the closer they are the more likely this will happen)
