<span>Extreme temperature and bedrocks
Tundra and desert both have shallow soil profiles because of the extreme temperatures and the bedrocks it has. In the case of tundra, it has extreme cold temperature and the soil were covered in ice in long periods of time. Because of this, the plants were unable to get water from the bedrocks resulting in plants dying. In the desert, however, it has extreme hot temperature making the plants unable to survuve due to lack of water in the environment and in the bedrocks. The plants that can only survive in this temperature are the plants that has the ability to store water in their system.</span>
The answer is Bantu.
They had already developed immunity to malaria due to exposure in their native environment.
As they migrated southwards to conquer more land, they met the pygmies and the Khoisan. The Bantus had carried with them the malaria vectors.
When the mosquitos infected the pygmies
and the Khoisan populations, who had no
immunity against malaria, the disease reduced their populations drastically hence
enabling the Bantus to conquer their
land.
1. Because they are unstable and can share electrons in their outer energy levels.
2. Polar molecules occur when there is an electronegativity difference between the bonded atoms. Nonpolar molecules occur when electrons are shared equal between atoms of a diatomic molecule or when polar bonds in a larger molecule cancel each other out.
U(uracil) and A(adenine); C(cytosine) and G(guanine)
Hope this helps:)
