mitosis/meiosis Flashcards
- How is the chromosome number maintained constant from generation to generation in sexual reproducing animals?
BEFORE YOU COMBINE TWO GENETIC CODES IN SEX (FERTILIZATION) YOU MUST TAKE EACH OF THE TWO DIPLOID PARENTS AND SEPARATE THEIR TWO GENETIC CODES. THIS IS CALLED MEIOSIS. YOU PUT ONE OF THEIR GENETIC CODES INTO A GAMETE CELL AND THE OTHER ONE IN ANOTHER GAMETE CELL. THEREFORE WHEN YOU COMBINE THE 1N GAMETE CELL WITH ANOTHER 1N GAMETE CELL, YOU WILL GET A BABY WITH NORMAL DIPLOID CELLS. THIS WILL KEEP THE CHROMOSOME NUMBER ALWAYS 2N.
What is the advantage to a species when crossing-over occurs?
VARIATION! VARIATION IS THE KEY TO EVOLUTION CHANGE.
haploid
monoploid
interphase
DNA replicate
prophase
nuclear membran taken apart
spindle fibers form and attach to chromosome
metaphase
spindle fibers bring chromosome to center
anaphase
chromosome copies separated by spindle
telophase
cell finish cytokenisis with new nuclear membrane and 2 cells
mitosis
replication and separation of chromosomes
cytokinesis
separation of cytoplasm
Oogenesis
eggs
2N-> small and big
dead eggs
polar
each human gamete has
a. the monoploid chromosome number
b. 23 chromosomes
c. diploid chromosome number
a
gamete
sex cell
how many sex cells are produced by a gamete of a male/female
millions/1
zygote
2 cells joined
pre-fetus
the non zygotes are the
polar bodies
diploid chromosomes in meiosis are results of
fertilization
can egg cells produce gametes?
no
meiosis happens during
a. mitosis
b. oogenesis
c. replication
oogenesis
paramecium
unicellular
found in plant mitosis but not animal mitosis
cell plate
found in animals but not plant mitosis
centriols
centriols
the things that go to the opposing sides of the cell