Some Bio quests.?

Question

1) A human cell may have more or less than 46 chromosomes as a result of nondisjuncion, a process in which
a. chromosomes fail to separate during cell division.
b. a fragment of a chromosome breaks off and is lost.
c. homologous chromosomes pair up and exchange segments of DNA.
d. genes are combined in new ways.

2)How does cell division differ between animal and plant cells?
a. Plant cells don't have centrioles; animal cells do.
b. Animal cells form a cell plate during cytokinesis.
c. Animal cells are always haploid.
d. Plant cells are pinched in half by a belt of protein threads.

3)Meiosis results in new cells with the _____ number of chromosomes of parent cell. When the _____ from a mother and a father fuse in the process of fertilization, the normal chromosome number is restored.

4) Before mitosis takes place, a chromosome is copied, resulting in two unseparated copies called _____.

Could you help me with these questions? Thanks.

If I knew the answer, I wouldn't be asking for help.

Answer 1

No problem, we all need a little help sometimes :)

1. A ( sometimes we get extra chromosomes if they break or less if they don't separate)

2. A (centrioles attach to the chromosomes to help them separate equally if not they would float around the cell and each cell may get uneven # of chromosomes.)

3. half (meiosis divides the 2n-diploid cell into a 1n haploid cell), gametes

4. chromatids

Good Luck!

Answer 2

1) A

2) i think its A

3) haploid, zygotes ? the idea is that meiosis is the division of a parent cell into 2 daughter cells, each with only half of the original number of chromosomes.

4) bi-smting? argh i cant remember sorry!!!

Answer 3

read your book kid. dont be lazy..

i believe its all in the book.