21 terms

CHAPTER 4 science test pt 1

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what two kinds of cells do organisms that reproduce sexually form?
body cells and sex cells
why are the chromosomes in organisms that reproduce sexually not identical to either parent?
you get 23 chromosomes from each parent
if both genes for fur color for a kitten are at the same place on homologous chromosomes, why might some kittens be orange and some gray?
one chromosome comes from mom and one from dad
if human cells are diploid, what are the number of pairs?
23
an organism's chromosomes can be matched as pairs of chromosomes that have _____ for the same ______.
genes; traits
why is it important for an organism to have the correct number of chromosomes?
genetic mutations like down syndrome or trisomy 18 can occur if you don't
what cells in an organism that reproduces sexually are diploid and which are haploid?
diploid = body
haploid = sex
meiosis
two divisions of the nucleus and cytoplasm
result of meiosis
4 haploid sex cells
main difference between the final product of meiosis I and the final product of mitosis
meiosis I-but sisters are not split.

mitosis- sisters are split.
the main difference between the final product of meiosis II and the final product of mitosis
mitosis- the 2 new cells are identical to each other and the parents

meiosis II- 4 cells only has half of the genetic information the parent has
what does meiosis ensure about future generations?
chromosome number of a species stays the same from generation to generation
meiosis forms ___ cells with the correct haploid number of ___________.
sex; chromosomes
how is the diploid number maintained?
each parent gives half of their diploid cells
how does meiosis create genetic variation?
from haploid sex cells
what happens to a body cell and its nucleus during mitosis and what is the result?
it divides once & produces two identical diploid cells
what happens to a reproductive cells and its nucleus during meiosis and what is the result?
it divides twice & produces four cells two pairs of identical haploid cells
what is the main advantage of sexual reproduction?
genetic variation
what four plants is wild mustard the common ancestor?
how did this happen?
broccoli, kale, cabbage, kohlrabi; selective breeding
selective breeding
to selectively develop particular traits
why can sexual reproduction be a disadvantage?
1. it takes time
2. energy
3. grow
4. develop
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