The germinal period ends approximately two weeks after conception. <span> This </span>stage<span> occurs during the first 2 weeks of development (or the 2nd - 4th weeks of pregnancy). The union of the sperm and egg cell forms a single cell called a zygote. </span>
Carbon dioxide—\text {CO}_2CO
2
start text, C, O, end text, start subscript, 2, end subscript—from the atmosphere is taken up by photosynthetic organisms and used to make organic molecules, which travel through food chains. In the end, the carbon atoms are released as \text {CO}_2CO
2
start text, C, O, end text, start subscript, 2, end subscript in respiration.
Slow geological processes, including the formation of sedimentary rock and fossil fuels, contribute to the carbon cycle over long timescales.
Some human activities, such as burning of fossil fuels and deforestation, increase atmospheric \text{CO}_2CO
2
start text, C, O, end text, start subscript, 2, end subscript and affect Earth's climate and oceans.
It is no charge so it is D
Answer:
b
Explanation:
lava is hot and needs to flow
Carbon dioxide and oxygen are two molecules that undergo this simple diffusion through the membrane.
