Answer:
30
Explanation:
The seed of an angiosperm is formed as a result of fertilization (fusion of sperm in pollens and the ova from ovary). According to the question, the cells of the seed which will grow into the plant contains 20 chromosomes. Seeds of angiosperms contain a tissue called ENDOSPERM that forms as a result of the unique DOUBLE FERTILIZATION in angiosperms. It occurs when one haploid sperm cell fuses with two haploid polar nuclei to form a triploid endospermic structure that serves as food for the growing embryo in the seed.
Now based on the above explanation, the diploid plant cell with 20 chromosomes will have 10 chromosomes (half as much) in its gametes as a result of meiosis. This 10 chromosomes in each gamete (sperm and ovum) fuses to form a diploid zygote with 20 chromosomes, while one haploid sperm cell (10 chromosomes) also fuses with two haploid polar nuclei (10 chromosomes each) to form a triploid endosperm with 30 chromosomes i.e. 10+10+10.
How does changing the type of exercise effect heart rate in bpm?
Or
How does changing the amount of reps of [insert exercise here] affect heart rate in bpm?
Explanation:
reduction takes place.......
Answer:
1) A, C and D
2) D
Explanation:
The normal hemoglobin is made up of heme and globin. The protein, globin is in turn made up of four polypeptide chains which include two alpha and two beta chains.
The gene gene responsible for the creation of the beta globin chain is located on the short arm of chromosome eleven. It is called the HBB gene. Many mutations occur on the HBB gene and a mutation on this gene produces abnormal hemoglobin like HBS, hbc, and hbe. HBs causes sickle cell anemia.
In sickle cell anemia, there is an alteration of the genetic code, leading to the substitution of a single amino acid where glutamic acid is replaced by valine in the sixth position of the beta chain.
In the mRNA, the change converts a glutamic acid codon(GAG or GAA) to a valine codon(GUA, GUC, GUU or GUG).
Sickle cell anemia is caused by a transversion that leads to a missense mutation.
