.Answer:
Option A, fix nitrogen inside nodules on the roots of legumes
Explanation:
Rizhobium bacteria live in symbiotic relationship with roots of leguminous plants such as pulses including alfalfa, soybean etc.
Rhizobium or Bradyrhizobium is a gram negative bacteria that satisfies the nitrogen starvation of host plant.
These bacteria get habitation and nutrition from these leguminous plants and in return they fix the nitrogen into the nodules of the roots. This is a kind of facultative association between soil bacteria rizhobium and legume plants.
Hence, option A is correct
Thus, option A is correct
Bacteria reproduces by cell division rather than meiosis.
1.
Anaphase. In <span>Anaphase the sister chromatids separate from each other to the opposite sides of the cells.
2. </span>
Chromosomes would not separate into two nuclei. <span>Mitosis is a process cell division, where one cell divides into two identical cells.
</span>
3.
Metaphase I. <span>Meiosis prophase I is the phase in which chromosomal crossing over occurs. The phase after prophase I is metaphase I.
4. </span>
Its body cells would have 36 chromosomes, and its gametes would have 18 chromosomes. <span>In the gametes, there are half of the number of chromosomes present in the body cell.
5. </span><span>
A species has to adjust rapidly to a changing environment. To adjust to the environment, crossing over is necessary, and it does not occur in mitosis, but meiosis.
6.
50 percent. Parents: Yy x yy
Offspring: Yy Yy yy yy
50 % is Yy and 50% is yy.
7. </span><span>
One parent had white eyes and the other was heterozygous for eye color. The ratio in the offspring is 50-50. The only possibility is the following:
Parents: Rr x rr
Offspring Rr Rr Rr Rr
8. </span><span>
Their fur will be a mixture of red and white hairs. The offspring will be heterozygous. They will have alleles for both red and white hairs and both will be expressed.
</span>
9. Not enough information.
10. <span>
Both of the parents' genotype must have been Pp. The genotype of the white plant is pp since it is recessive:
Parents: Pp x Pp
Offspring: PP Pp Pp pp
One of the four is white.</span>
<span>During nitrification, ammonia is changed back into nitrate.</span>
Nitrification is a three-step process of oxidation of ammonia. It is an aerobic process performed by small groups of autotrophic bacteria (<span>Nitrosomonas,
Nitrobacter</span>).
First step- ammonia to hydroxylamine,
Second step-hydroxylamine to nitrite,
Third step-nitrite to nitrate.
Nitrification together with ammonification is part of a nitrogen cycle.
Answer: a) substrate and cofactors b) covalent modification
Explanation:
Metabolic pathways involve all the chemical processes takes place in the enviornment or in an organisms.The metabolic pathways are controlled through the catalytic activities of enzymes.
The availability of enzyme is regulated by substrate and cofactors present in enzyme and enzyme activity is commonly regulated via covalent modification.
Enzymes are highly selective in nature and bind to a specific substarte only. The active site in enzyme binds with the substrate to form enzyme substrate complex. Coactors assist the enzyme activity, without cofactor enzyme can not perform its activity.
Hence enzyme availibility is regulated by substrate and cofactors regulates.
Covalent modifications regulates activity of enzyme as it involves addition and removal of chemical group to synthesis required protein. It can change the chemical properties of the site by targeting one or multiple amino acid.
Thus the correct answer is a) substrate and cofactors b) covalent modification
