Answer:
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Explanation:
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Answer:
There is 46 pairs of chromosomes.
Tin, because it has five energy levels with four electrons in the fifth level
.
Explanation:
Tin has an electronic configuration as
1s2,2s2,2p6,3s2,...........4d10, 5s2,5p2
They have four valence electrons in their outer shell
Among the four diagrams given Tin is least reactive because the atomic radius of tin is largest among all four options. Due to large atomic radius electronegativity decreases and hence Tin is the least reactive element among Neon, Chlorine, gallium and tin.
The electronegativity of an element is its tendency to complete its octet by attracting electrons towards itself. Also tin is at the lowest place in the periodic table among all the four mentioned elements, its ionization energy is also low hence less electronegative and least reactive.
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.