I believe <span>peptidoglycans (Murein) contain both d and I-amino acids.</span>
Answer:
C) Primary, tertiary and quaternary levels of protein structure
Explanation:
Primary structure; Covalent bond is present in form of peptide bond in the primary structuture of proteins. The amino acids are held together in the polypeptide chain by peptide bond.
Tertiary structure; Disulfide bonds are present between cysteine amino acids, that keeps the parts of polypeptide chain strongly attached to one another.
Quaternary structure; The Quaternary structure of protein is held together by hydrophobic interaction and disulfide bonds.
The angle of jaw and type of teeth in each jaw are the main big differences.
<span>the feeding veins (xylem and phloem) are at work</span>
Answer: Natural selection is selection due to environmental conditions from random genetic mutations in a population. Among the variants in a population, some will be slightly better adapted to conditions and will eventually out-compete the rest of the population. Survival of the fittest actually means survival of the best adapted, or fittest for purpose, i.e. to survive and thrive.
Explanation: This phrase has caused much miunderstanding of the evolutionary process. ‘Fittest’ has been equated with biggest, or strongest or fastest, but this was a description originating in the nineteenth century, when it was understood quite differently.
Natural selection arises from genetic variation in a population. Jaques Monod, an esteemed scientist, described evolution as where chance and opportunity meet. Chance lies in the genome of a species, random mutations, and the resulting genetic variation in the population.
Opportunity lies in the environment. Environmental change creates opportunities for some, extinction for others. Opportunities can also be from exploiting new environmental niches.
Natural selection is the process by which some random genetic variation gives some of a population a competitive advantage. competition eventually results in one population out-competing all others in its niche. The end-result of competition in nature is monopoly.
But this process continues and further random mutations can result in another population becoming better adapted. That is the actual meaning of survival of the fittest: in modern terms we might say ‘fittest for purpose’, that is, the species orvpopulation best adapted to survive and thrive in that environment.
