Answer:
a) Acetylcholine is degraded by acetylcholinesterase.
Explanation:
After it binds for its receptor on the plasma membrane of the postsynaptic cell, acetylcholine must be removed in order to prevent repeated stimulation. Acetylcholinesterase is enzyme for the inactivation of acetylcholine, present at all cholinergic synapses. This enzyme hydrolyses acetylcholine and breaks it to the acetate and choline. Choline can be reused for the synthesis of the new acetylcholine molecule so it is taken back into the presynaptic cell.
Answer:
variation
Explanation:
Genetic variation is what makes us all unique as a result of subtle changes in our DNA. The Theory of Evolution is a process in which organisms change over time as a result of adapting to their environment. Charles Darwin came up with the term Survival of the fittest, in any environment plants and animals from the same species show natural variation in their physical characteristics, like neck lengths in giraffes. Darwin suggested that the plants and animals best suited to the environment will survive and pass on their characteristics to their offspring. Over time, the characteristics of the surviving members of the species will become predominant.
Example: Peppered moth
In London in the 1800's, 98% of peppered moths had light colored bodies and only 2% were dark. The light moths were the same color as the trees so they could easily hide from hungry birds and not get eaten. The dark moths however were easy to see and were eaten. Then came the factories and smoke of the industrial evolution and many trees turned black with soot and suddenly the dark moths were able to survive better as they now looked like the trees and the light colored moths were easier to spot and eat. By 1895 the dark peppered moths made up 95% of the population and the light colored moths only 5%. This is an example of natural selection, because of the gene that makes the moths dark, it allowed them to flourish when the environment changed, they adapted, reproduced and survived.
The answer is:
For the farmers own needs
D. Lymph nodes are the filtering points throughout the body... found in the lymphatic system
Answer:
transcription of mRNA from DNA
small ribosomal subunit binds to mRNA
initiation complex formed with addition of large ribosomal subunit
translocation
codon recognition (non-initiating site)
peptide bond formation
ribosome reads a stop codon
polypeptide chain is released from the P site
ribosomal subunits dissociate
Explanation:
The above describes the process of translation in the ribosome. After transcription of DNA to mRNA, the mRNA is taken to the ribosome to undergo translation, here the mRNA binds to the small ribosomal subuits and to other initiation factors; binding at the mRNA binding site on the small ribosomal subunit then the Large ribosomal subunits joins in.
Translation begins (codon recognition; initiating site) at the initiation codon AUG on the mRNA with the tRNA bringing its amino acid (methionine in eukaryotes and formyl methionine in prokaryotes) forming complementary base pair between its anticodon and mRNA's AUG start codon. Then translocation occurs with the ribosome moving one codon over on the mRNA thus moving the start codon tRNA from the A site to the P site, then codon recognition occurs (non-initiating site again) which includes incoming tRNA with an anticodon that is complementary to the codon exposed in the A site binds to the mRNA.
Then peptide bond formation occurs between the amino acid carried by the tRNA in the p site and the A site. When the ribosome reads a stop codon, the process stops and the polypeptide chain produced is released and the ribosomal subunits dissociates.
