Sperm cells inside the pollen grain travel down the pollen tube and into the ovary which contains the ovules. Fertilization occurs when one of the sperm cells fuses with the egg inside of an ovule
Answer:
Oil shale is a form of sedimentary rock that contains kerogen, which is released as a petroleum-like liquid when the rock is heated. Tar sands are a combination of clay, sand, water and bitumen, which is a heavy hydrocarbon.
Additional info:
The term oil sands refers to a particular type of nonconventional oil deposit that is found throughout the world. Oil sands, sometimes referred to as tar sands, is a mixture of sand, clay, other minerals, water, and bitumen. The bitumen is a form of crude oil that can be separated out from the mixture.
The primary distinction between crude or conventional oil and shale oil is the way it collects. The oil in shale is typically found in smaller batches. As a result, shale oil often needs to be fractured so that the oil trapped within the shale can be recovered.
Both photosystems contain many pigments that help collect light energy, as well as a special pair of chlorophyll molecules in the heart (reaction center) of the photosystem. The special pair of photosystem I is called P700, while that of photosystem II is called P680.
Answer:
A
Explanation:
a theory is usually supported by evidence or another laws rules. it must have pretty strong evidence, but it can NOT become a law. a law is set in stone, and proved by math.
