Because there are millions in our body
Answer:
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.
Answer:
except natural killer cells.
Explanation:
The Helper T cells produce cytotoxic T cells and help B cells, but not natural killer cells
Answer:
nitrogenous bases from the cytoplasm link up with an exposed complementary base
Answer:
GAR and AICAR transformylase
Explanation:
Tetrahydrofolate is essential for purine and pyrimidine synthesis, its deficiency can lead to inhibition of nucleic acid such as DNA and RNA and protein synthesis, which are important for the growth and survival of both normal cells and cancer cells. N-10-formyltetrahydrofolate acts as a donor of carbon atoms to the actively growing bases. It contribution is mediated by the action of the Glycinamide Ribonucleotide (GAR) transformylase and the N-5-aminoimidazole-4-carboxamide ribonucleotide (AICAR) transformylase.