Match the following.

1 . the stage on the first meiotic division when the homologous chromosomes move to opposite poles but the sister chromatids remain together.
2 . the stage in the second meiotic division where sister chromatids migrate to opposite poles
3 . a structure on the chromosome that holds a pair of chromatids together during replication
4 . a double-stranded chromosome following replication attached by a centromere
5 . a condition where non-sister chromatid of homologous chromosomes exchange genes
6 . the stage in the first meiotic division where the homologous chromosomes line up as a pair
7 . the stage in the second meiotic division where the chromatid pair lines up at the equator of the cell

a. metaphase i
b. anaphase i
c. anaphase ii
d. chromatid
e. crossing over
f. centromere
g. metaphase ii

1 . The stage on the first meiotic division when the homologous chromosomes move to opposite poles but the sister chromatids remain together

: b. Anaphase I

2 . The stage in the second meiotic division where sister chromatids migrate to opposite poles

: c. Anaphase II

3 . A structure on the chromosome that holds a pair of chromatids together during replication

: f. centromere

4 . A double-stranded chromosome following replication attached by a centromere

: d. chromatid

5 . A condition where non-sister chromatid of homologous chromosomes exchange genes

: e. crossing over

6 . The stage in the first meiotic division where the homologous chromosomes line up as a pair

: a. Metaphase I

7 . The stage in the second meiotic division where the chromatid pair lines up at the equator of the cell: g. Metaphase II

Explanation:

DNA replication occurs during the S phase of the interphase of the cell cycle. The replicated DNA molecules are accommodated in two sister chromatids of a chromosome that are held together by a centromere.  

During prophase I, the chromatids of a homologous chromosome pair exchange a genetic segment. This process is called crossing over. It generates recombinant chromatids with new combinations of genes.

Metaphase I of meiosis I includes the alignment of homologous pairs of chromosomes at the cell's equator. This is followed by separation and movement of homologous chromosomes to the opposite poles of the cell during anaphase I.  

Metaphase II of meiosis II includes the alignment of individual chromosomes, each with two sister chromatids, on the cell's equator. During anaphase II, splitting centromere separates the sister chromatids which then move to the opposite poles of the cell.

step 1: initiation

initiation is the beginning of transcription. it occurs when the enzyme rna polymerase binds to a region of a gene called the promoter. this signals the dna to unwind so the enzyme can ‘‘read’’ the bases in one of the dna strands. the enzyme is now ready to make a strand of mrna with a complementary sequence of bases.

step 2: elongation

elongation is the addition of nucleotides to the mrna strand. rna polymerase reads the unwound dna strand and builds the mrna molecule, using complementary base pairs. there is a brief time during this process when the newly formed rna is bound to the unwound dna. during this process, an adenine (a) in the dna binds to an uracil (u) in the rna.

step 3: termination

termination is the ending of transcription, and occurs when rna polymerase crosses a stop (termination) sequence in the gene. the mrna strand is complete, and it detaches from dna.