The assortment of homologous chromosomes during meiosis is random and generates genetic variation, the raw material for evolution.
During metaphase I of meiosis, homologous chromosomes are lined up at the equator plate of the cell in order to be separated (assorted) in anaphase I.
The separation of homologous chromosomes during meiosis I is random. Daughter cells receive unique gene combinations from an original parent cell.
Subsequently, haploid cells got from two successive meiotic divisions fuse during fecundation to form a diploid (2n) zygote.
During prophase I, non-sister chromatids interchange genetic material by a process known as recombination. This genetic process also increases genetic variation in daughter cells.
In conclusion, the assortment of homologous chromosomes during meiosis is random and generates genetic variation.
The temperature depends to the certain point
Answer:
100% or 1
Explanation:
This question involves a gene coding for fur color in bears. According to the question, black fur allele (B) is dominant over the brown fur allele (b). This means that a bear heterozygous for fur color (Bb) will be phenotypically black.
In this question, a black father bear (genotype BB) and a brown mother bear (genotype bb) were crossed, the baby bears will all have a genotype Bb (see punnet square in the attached image). Since all the offsprings of this cross have genotype Bb, this means that 100% will have black fur.
Answer:
here.
Explanation:
Due to the prevalence of malaria in Africa, the allele for sickle cell anemia (HbS) provides a selective advantage. That's why it remains in the population.
A normal African person (HbAHbA), with normal haemoglobin, will not die of anemia, but will die of malaria.
An African person with sickle cell anemia (HbSHbS), with abnormal haemoglobin, will die of anemia.
A heterozygous African person (HbAHbS), with half of his red blood cells (RBCs) being normal and the other half being sickle-shaped, will neither die from anemia, nor malaria since the plasmodium will be incapable of completing its life cycle in the abnormal RBCs.
Thus heterozygous African people will grow, reproduce and pass on the HbS allele to the next generations.
