I'm pretty sure it is the left ventricle.
Answer:
Postzygotic isolating mechanism
Explanation:
Reproductive isolation can occur due to prezygotic or postzygotic isolating mechanism. Prezygotic mechanism prevents fertilization of gametes and can occur due to different mating behavior, different mating time period etc. Postzygotic mechanism occurs after the formation of zygote i.e. the organisms are able to mate and fertilization also occurs. However the resultant zygote may not survive. It might not survive immediately or might die before reaching the reproductive maturity. Such a situation would still come under reproductive isolation because the resultant offspring is not viable and not able to pass on the genes to the next generation.
Answer:
Enzymes
Explanation:
The regulation of gene expression is the central dogma of life. It is a series or set of mechanisms in which genetic information in the DNA expresses in the form of RNA or protein. Cells give gene expression b different mechanisms as transcription, maturation of mRNA, and translation.
During these mechanisms, different gene-regulatory proteins are influenced. For example, a set of RNA polymerases that are proteins transcribe the DNA molecule during transcription. Transcription factors are also proteins that control the synthesis of proteins in the cell. These proteins are an enzyme that catalyse the gene regulation in the human cells.
Answer:
The nitrogen cycle could not exist without first nitrogen. The cycle is about this specific element which goes to show that if this element is not present then, there will not be any nitrogen cycle. Also, an important factor for the cycle is the presence of the bacteria and other microorganism which are needed for the fixation.