a mature egg is fertilized when it is joined with a sperm cell
the answer is B
Answer:
The correct answer is -
Parent 1: RW, Parent 2: RR
Explanation:
In the given punnet square there are four offspring and it is a monohybrid cross between parent 1 and parent 2. The four offspring produced in this cross have RR, RR, RW, and RW alleles. By the genotype of the offsprings, it is clear that there are 50 percent pure or true-bred and 50 percent are heterozygous.
Each parent contribute two alleles and these alleles are independently assort in the zygote to form offspring so there must be R, R, R and W allele present in the parent
Parent 2 → R R
Parent 1 ↓ R RR RR (one allele (R) come from each parent in zygote)
W RW RW (one allele (R and W) come from each parent)
The genotypes that indicates a homozygous dominant trait is : B. TT
Homozygous : both alleles must be the same, so it eliminate option A.
Dominant trait : One of the allele must be written in Capital letter, so it eliminate option C.
this leaves option B, as the answer
hope this helps
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.
