Answer: color, cleavage, clarity, durability, and crystal system
Explanation: color - distinctly green color that ranges between bluish green and slightly yellowish green.
cleavage - one direction of imperfect cleavage
clarity - almost every natural emerald has eye-visible characteristics that can be inclusions, surface-reaching fractures, or healed fractures. Treatments to fill the fractures with oils, waxes, polymers, flux and other materials to reduce their visibility has been common practice for hundreds of years.
durability - emerald is very hard, but almost all specimens have inclusions and surface-reaching fractures that compromise their durability
crystal system - hexagonal
Answer:
The correct answer would be Y-chromosome analysis.
Y-chromosome analysis is technique used to search the parental line of a boy on his father's side.
Gender of a person is determined by 
chromosome in humans. XX is present in females and XY is present in males.
Mother always passes X chromosome to her progeny but father passes both X and Y chromosomes. If X is passed from the father then the offspring will be a girl and if Y is passed from the father then the offspring will be the son.
The sons (F₂) of this son (F₁) will also bear the same Y chromosome as that of grand father (P).
Thus, Y chromosome always passes from father to son and hence, Y-chromosome analysis can help in identification of father of this young boy.
Answer: James Watson, Francis Crick, and Rosalind Franklin (these are just 3)
Explanation:
In 1952, Watson and Crick took the first X-ray picture of DNA. Created by Rosalind Franklin, she used a technique called X-ray Crystallography, that is how they discovered the helical structure of DNA
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.
