Answer:
The correct answer is A
Explanation:
Eukaryotic cells have a nucleus containing their DNA, whereas prokaryotic cells do not have a nucleus.
Answer:
True
Explanation:
During contraction of skeletal muscle fibers, the thin filaments slide inward toward the A band's center as a result of cycles of crossbridge binding and bending.
The answer is ‘behavioral isolation’. It is a form of
sympatric speciation - which occurs even when
species live in the same habitat. In this case,
the individuals in the population are isolated by differences in mating and probably different mating rituals.
The correct answer is all of them:
<span>A.is only found in eukaryotes
B.is found in the nucleus of prokaryotes
C.controls the physical traits of an organism
D.determines the sequence of amino acids in proteins
E.can control certain organism behavior
F.is a long, single chain of paired nucleotides</span>
Answer:
c. Pyridostigmine binds to the acetylcholinesterase active site and prevents sarin from binding to and modifying the enzyme active site.
Explanation:
Sarin is a toxic compound which inhibits acetylcholinesterase enzyme. This enzyme degrades the neurotransmitter acetylcholine after the required muscle cell stimulation. In absence of its activity, acetylcholine is not degraded and the muscle cells are stimulated uncontrollably. The muscles are not able to relax which ultimately proves fatal for the victim.
Pyridostigmine is also an acetylcholinesterase inhibitor like Sarin. However its period of inhibition is short compared to organophosphorus inhibitors like sarin. It competes with sarin and replaces it in the active site of acetylcholinesterase. The enzyme is still inhibited but for a shorter time as compared to inhibition by Sarin. Hence after sometime, it becomes functional again and resumes its normal activity. Acetycholine starts getting degraded relaxing the muscles.
