Answer:
Extrinsic regulatory mechanisms are external and depend on the firing of some factor outside the population itself. Among them are interspecific competition, food and space restrictions, very strong climatic variations, weathering and inharmonious relationships with other populations (parasitism and predatism).
Good examples of interspecific competition appear when rabbits, caves, rats compete for the same plant, or different fish and birds, such as the heron, vie for the same species of smaller fish. This is because these different species keep their populations in the same ecological niche. Competition is often so strong that some species eventually, as one example of an extrinsic homeostatic mechanism overriding an intrinsic homeostatic process is their disappearance or migration to other regions.
In this competition, the presence of adaptations among individuals in the population that promote better food search, speed, vision, and others can make the difference between elimination and survival.
Answer:
B
Explanation:
Warm because land gains heat faster than water when heated by the sun. The heated land then transfers the heat to the atmosphere. The air mass is dry becasue a continent is mainly land and very little water (unlike oceans). There is, therefore, very little moisture in the continental tropical air mass.
Answer:
Option C thymine is a pyrimidine base in DNA
Explanation:
1) The stage in which chromosomes are multiplied is interphase.
2) Nuclear division? It should be mitosis but since its not there I'm guessing Prophase
3) sorry.. i forgot :) hope i helped somewhat though
Answer: The following is a <u>postzygotic isolating barrier </u>:
- The hybrid offspring of two species of crocodiles can produce normal gametes but cannot obtain a mate.
Explanation:
<em><u>Reproductive isolation </u></em>occurs when <em>barriers prevent</em> two populations from interbreeding , <u>keeping their gene pools separate.</u>
We can find the Prezygotic isolation that occurs<u> before fertilization </u>can happen.
And the Postzygotic insolation barriers are the reproductive insulation processes that<u> act after the mating</u>. They are all that concern the viability of the individuals produced.
Prezygotic isolation barriers can be temporal, behavioural, geographic , ecological or mechanical; whereas postzygotic isolation barriers include the inviability, infertility or breakdown of hybrid organisms
