Ans.
Sickle-cell disorder shows defected red blood cells, due to mutation in gene that code for hemoglobin. The mutated genes for sickle-cell disease are found in higher percentage of sub-Saharan African population as it provides protection against malaria as compared to population of United States.
Malaria is common in sub-Saharan Africa region and there, natural selection favored gene for sickle cells, because it might be beneficial to people having sickle cell disease that makes them able to survive in such condition and transmit their genes to offspring.
On the other hand, in those Africans, who moved to United States, where malaria is uncommon or absent, natural selection favored normal, wild type genes, resulting in fewer people with defected sickle cell.
Thus, the evolutionary process behind this is 'natural selection.'
Answer:
47 chromosomes
Explanation:
Meiosis is a kind of division that reduces the chromosome number of the daughter cells by half i.e. 2n - n. It occurs only in reproductive cells to produce sex cells or gametes. In humans, meiosis occurs to produce gametes (egg and sperm) that have 23 haploid chromosomes.
N.B: Somatic human cells have 46 chromosomes
According to this question, a meiotic error occurred during gamete formation, resulting in an egg that has 24 chromosomes. If that egg is fertilized by a normal sperm i.e. sperm with 23 chromosomes. A zygote that posseses (23 + 24) = 47 chromosomes will be produced.
Answer:
1. diploid, haploid
2. sister chromatids, diploid
3. diploid
4. homologous chromosomes
5. diploid
6. homologous chromosomes
I haven't learnt this yet but I did my best.
hope this helps<3
1. Flowers must rely on vectors to move pollen. These vectors can include wind, water, birds, insects, butterflies, bats, and other animals that visit flowers. We call animals or insects that transfer pollen from plant to plant “pollinators”.
2. Germination:When a seed falls on the ground, it needs warmth and water in order to germinate; some seeds also need light. Dicots have seed coats that soften with moisture. After being planted in the soil for a few days, the seed absorbs water and swells until the seed coat splits.
