The right answer is 2.
A prothallus is a small thin blade of chlorophyllian cells when it is green but can also be colorless and saprotrophic. It is derived from the development of a protonema formed during the germination of a spore in pteridophytes (Pteridophyta, ferns and other closely related species). It is a structure formed by mitotic divisions of haploid cells.
<span>The correct answer is A. Carbon. That's why things like breads and other whole grain foods, including all types of pasta, are called carbohydrates. They are a great source of quick energy but one should not eat a lot of them because they can make you obese if you're not careful. Chocolate and other sweets are also great sources of carbohydrates. </span>
In the block to polyspermy, entry of the sperm's contents causes calcium ion levels in the oocyte's cytoplasm to rise, triggering the cortical reaction.
In biology, polyspermy describes the fertilization of an egg by more than one sperm. Diploid organisms normally contain two copies of each chromosome, one from each parent.
The cell resulting from polyspermy, on the other hand, contains three or more copies of each chromosome—one from the egg and one each from multiple sperm. Usually, the result is an unviable zygote. This may occur because sperm are too efficient at reaching and fertilizing eggs due to the selective pressures of sperm competition.
The cortical reaction is a calcium-dependent exocytotic process in which the content of secretory granules is released into the perivitellin space immediately after fertilization, which serves to prevent polyspermic fertilization.
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The moon is a satellite because it moves around Earth. Earth and the moon are called "natural" satellites. Satellites fly high in the sky, so they can see large areas of Earth at one time.
Earth is a satellite of the Sun and the Moon is a sub-satellite orbiting Earth.If the Moon somehow ended up outside Earth's Hill sphere, the Moon would orbit the Sun instead of the Earth just like all the other planets, asteroids, and comets.
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Answer:
A and B are the answers.
Explanation:
Believe me I took a test a while ago with this question