Answer:
1- Presence of phenotypic variation
2- some phenotypic variation due to genetic variation
3- the given trait has an impact on fitness
Explanation:
The evolutionary theory by natural selection proposed by Darwin in his publication “On the origin of species” (1859) is based on a series of assumptions that enable to understand the amazing biodiversity on the Earth. First, individuals are not identical among them, i.e., there exists variation in the traits among the members of a given population, species, etc. Second, phenotypic variation leads to differential survival and reproduction of the organisms that are best fitted to the environment (i.e., competence among the members of the population). Finally, phenotypic traits are passed from generation to generation (i.e., phenotypic variation is inheritable), thereby favoring offspring from parents more adapted to the environment.
The answer to this question is histidine. Histidine i<span>s an </span>α-amino acid<span> involved in the biosynthesis of </span>proteins. The structure of histidine includes<span> an </span>α-amino acid<span>, a </span>carboxylic acid group<span>, and an </span>imidazole<span> side chain. Histidine was initially thought to be </span>essential<span> only for infants; however, it has since been found to be essential for adults too.</span>
Answer : A : They live in extreme environmental conditions.
Endocrine glands secrete hornmones whereas
exocrine glands secrete enzymes....
here, Pituitary gland secrete stimulating and growth hormone and thyroid gland secrete thyroxine hormone whereas salivary gland produce enzyme called saliva
So,pituitary gland and thyroid gland are endocrine and salivary glands are exocrine...
HOPE THIS HELPS YOU!!!!!