The molecular clock is a scientific technique which presents a means of estimating evolutionary rates and timescales using genetic data. It uses mutation rate of biomolecules when two or more life forms diverged to estimate the time. Answer is B.
Diffraction occurs when a wave moves through an opening in a barrier. This causes the wave to change direction and spread out.
Waves can behave in three different ways depending on the obstacles they encounter. They can reflect, refract or diffract. In diffraction, waves such as sound, light or water either bend around small objects that obstruct their passage or spread out as they travel through a gap in the barrier.
The degree of diffraction forms a direct relationship with wavelength. It generally increases as wavelength increases. Conversely, the amount of bending lessens as wavelength decreases. However, if the opening of the barrier is smaller than the wavelength, the effect of diffraction is not easily observed. Hope this helps.
Answer: number 1
Explanation: that is when we could first sustain life because that is when we gained atmosphere and when we could hold carbon and oxogen
<span>Fires can help eliminate the roots and shoots of invasive plants and stimulate growth of native species. Controlled fires can eliminate infected plants and enrich the soil. Controlled fires can also eliminate overcrowding of plants or trees. It can eliminate diseased or damaged plants as well.</span>
I think this is what you are referring to.
Hope this helps.