A. Geographical Isolation
Explanation - Geographical Isolation alludes to the physical obstructions that exist that shield two species from mating. For instance, a types of monkey that is situated on an island can't breed with another types of monkey on the terrain.
The water separates the two species by keeping them secluded from each other and make it unthinkable for them to breed. In this case, fishes of different ponds cannot breed because they are separated from one pond to another.
Linkage refers to the tendency of inhertance of the DNA sequences that are close together on a chromosome during the meiosis of sexual reproduction. It can be measured by the recombination frequency.
Recombination frequency describes the proportion of recombinant offsrpring produced in a genetic cross between two organisms. It is the frequency with which a single chromosomal cross over takesplace between two genes during the process of meiosis. Recombination frequency (RF) is given by
RF= Recombinants /total offspring x 100.
In the above example, the number of recombinant offspring is 20 and the total offspring is 400. By substituting these values,
RF= 20/400 x100
= 5.
The recombination frequency for the above cross is 5.
The correct option is this: TWO DRAGONFLY SPECIES REGULARLY MATE BUT THEIR GAMETES ARE INCOMPATIBLE.
In biology, there are different types of reproductive barriers, one of these is prezygotic barrier. A prezygotic barrier is a kind of mechanism that prevent reproduction from occurring by blocking fertilization. In this case, the concerned species will be mating together, but their gametes will not be compatible and thus, zygote will not be formed.
A postzygotic barrier on the other hand is said to occur when the reproduction process is blocked after the formation of zygote or after fertilization has taken place. A good example of this is an hybrid mule that is sterile and can not reproduce.
Answer:
3. The equator receives more direct sunlight than the North Pole.
Explanation:
<h2>The equator is the longest latitude at 0°.</h2><h2>The equator isn't influenced any change when the earth revolves around the sun cause winter and summer. </h2><h2>That's why equator is warmer than north and south pole.</h2>
<h2>I hope you understood</h2>
The type of competition that exist between the two species is INTERSPECIFIC COMPETITION.
There are basically two types of competition in any given ecosystem, these are intraspecific and interspecific competition. Intraspecific competition occurs among organisms of the same species while interspecific competition occurs among organisms of different species.<span />
