The correct answer to this question is this one: they lacked oxygen. The earliest organisms were completely heterotrophic in nature because of the reason that they lacked oxygen. <span>A heterotroph is an organism that cannot fix carbon and uses organic carbon for growth. </span>
Answer:
Geography affects the weather in many ways. ... Topographical features like mountains affect the weather mostly in the way that they direct air currents. For example, air is forced to rise over mountains. Moist air will cool as it rises, and then the clouds release the water, causing precipitation like rain or snow.
Explanation:
base on research.. hope it helps
Answer: centrioles and centrosomes
Explanation:
Centrioles are small granules found near the nucleus of ONLY animal cells from which flagella and cilia arise. Its functions include
- helping in cell division
- serving as basal body
Centrosomes also is located near the nucleus of animal cells and arranges microtubules. Its function is mainly giving protection to cell.
The answer is; the melanin in darkly pigmented skin protects DNA from UV radiation, and UV radiation can cause skin cancer
In Africa, due to its equatorial latitude location, receives direct sunlight at more or less 90 degrees most of the year. These highly concentrated rays increase the UV radiation exposure that can cause damage to cell DNA. Selection pressure, therefore, favored individuals with high melanin concentrations that protect against UV. Therefore population evolved towards high melanin densities in the skin.
It's G, since plants need carbon dioxide to perform photosynthesis
