Atom is the basic element of all living things because it's small. It is the smallest constituent unit of matter which has the properties of a chemical element. They are very small. Sizes are about 100 or 100, 000 fm. They are unstable. They are composed of a nucleus and electrons.
Answer:
The correct answer is D. How closely related the two species are to each other
Explanation:
Genome maps of every individual is unique. Genome map is the order of sequence of nucleotide which is present in an organism. Comparison of genome map allow the scientist to know how much closely related two organisms are.
The map of two individuals of the same species is almost the same. Similarly, the two same species have a more similar genome map than two distantly related species because they share most recent common ancestor.
For example, humans and chimpanzees are more similar than other apes so 96% of the genome are identical between them. So the right answer is D.
Answer:
This is correct. The remaining portion:
Sympatric species that form interrelationships undergo coevolution.
Allopatric species in different environments can undergo convergent evolution.
Allopatric species in small populations and under intense environmental conditions can undergo genetic drift.
Explanation:
On the basis of geographical distance, speciation is of two major types:
- Sympatric
- Allopatric
Sympatric Speciation:
Sympatric speciation is the formation of new species with no gergraphical separation from the ancestor. The new and parent species both exist in the same environment but do not interbreed due to mechanisms of reproductive isolation. These involves both prezygotic and post zygotic barriers to reproduction such as timing of mating, sensitivity to pheromones, choice of mating sites or infertility and mismatched gametes. Species formed through sympatric speciation can form interrelationships and undergo coevolution i.e. the evolution of ones species is dependent on the other.
Allopatric Speciation:
It involves the geographical separation of the parent and new species. These species could be geographically separated by a river, mountain range or land mass.
Although, allopatric species evolve independently, they may develop similar characteristics that serve different functions. Allopatric species in radically different environments undergo convergent evolution i.e. species evolve similar characteristics without any ancestral homology.
Allopatric species that reside in small populations and are under harsh environmental pressures undergo a rapid genetic revolution i.e. genetic drift. This includes the Founder's and bottleneck effect that involve the continuation of a species from very few individuals after a drastic, sudden environmental change.
