Genes is found in the DNA. It decides a specific characteristic. Genes can transform and take two or more option structures and these structures are called Alleles. Presently allele happens in an altered spot in a chromosome and in people we have two arrangements of chromosomes.
There are 46 chromosomes in the human. 23 from the dad, 23 from the mother = 46 chromosomes.
Yes, Organisms compete for the resources they need to survive like food, air, water, space. In areas where these are sufficient, organisms live in comfortable co-existence, and in areas where resources are abundant, the ecosystem boasts high species richness (diversity).
Pepsinogen, an inactive zymogen, is secreted into gastric juice from both mucous cells and chief cells. Once secreted, pepsinogen is activated by stomach acid into the active protease pepsin, which is largely responsible for the stomach's ability to initiate digestion of proteins.
The proteins(particularly enzymes) of the membrane help chemical reactions.
An example would be enzymes involved in electron transport chain.