the are puppets that have human emotions
Answer:
The cells that make up the xylem are adapted to their function: They lose their end walls so the xylem forms a continuous, hollow tube. They become strengthened by a substance called lignin . Lignin gives strength and support to the plant.
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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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B cells produce antigen
t cell are helper,killer,memory cells
they hold memory of pathogens i the system
Answer:
Explanation:
Photosynthesis is the process plants use to convert energy from the sun into usable energy for their cells. Plants use the light energy of the sun, carbon dioxide, and water to make glucose (a sugar), and oxygen. The energy of the sun is captured and stored in the bonds between atoms in glucose molecules.