Answer:
The initial step in the formation of an aminoacyl-tRNA is activation of the amino acid by reaction with ATP
Explanation:
In protein synthesis, the first step involves the formation of an aminoacyl-tRNA. This reaction is catalyzed by the the Mg²⁺-dependent enzymes known as aminoacyl t-RNA synthetases and occurs in two steps.
The first step of the reaction of the formation of an aminoacyl-tRNA is the activation of the amino acid by the attachment of an AMP molecule formed from the hydrolysis of ATP to AMP and pyrophosphate. The aminoacyl adenylate intermediate is bound to the enzyme in this initial step. Subsequently, in the second step of the activation of the amino acid, the aminoacyl adenylate intermediate is then transferred to its specific tRNA. The pyrophosphate formed in the first step is hydrolyzed to 2 phosphate molecules by a pyrophosphatase.
The overall reaction step is illustrated below:
Amino acid + tRNA + ATP -----> aminoacyl-tRNA +AMP + 2Pi
Some _club____ fungi can be eaten, but there are also some that are harmful to plant life, like wheat rust. club sac zygote-forming chytrid imperfect
Answer:
The correct answer is: Yes, this is an example of Reproductive Isolation.
Explanation:
- Reproductive Isolation can be defined as the mechanism adopted by different species during the course of their evolution, due to which the individuals belonging to different species are incapable of mating with each other and producing viable offspring.
- The given question is an example of Mechanical, Pre-zygotic Reproductive Isolation.
- Prezygotic Isolation refers to the mechanism adopted by individuals of different species during the course of evolution such that successful fertilisation of gametes from individuals of different species never occur, hence a viable zygote is never formed.
- Mechanical Isolation refers to the mechanism adopted by individuals of different species during the course of evolution such that their reproductive organs or the organs that assist in the process of reproduction are incompatible to each other. Hence, the gametes of each species are unable to come in vicinity of each other.
- Here, the pollen grain from the flower of one species of juniper is unable to form the pollen tube when its sits on the stigma of the flower of another species of juniper. This is an example of Mechanical Isolation.
