Any mutations in DNA are forever, since DNA is the master blueprint. All mutations will be passed onto new cells through DNA replication, and all RNA made from that DNA will also have the mutation. If the mutation occurs in sperm or egg cells, those mutations will also be passed on to the organism's offspring.
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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Answer:
D - vasodilation
Vasodilation is the widening of the blood vessels, it results from relaxation of smooth muscle cell within the vessel walls. It's not an example of negative feedback mechanism
Explanation:
What is homeostasis
It's a tendency of an organism or a cell to regulate it's internal environment and also maintain equilibrium using a system of feedback controls.
There are two types of feedback mechanism
We have both positive and negative feedback mechanism
The negative feedback mechanisms in living things regulate critical body processes.
Examples are : body sweating, body shivering, regulstion in sugar level.
Answer:
The atoms of each element have a characteristic number of electrons arranged in electron shells. The number of valence electrons determines what types of bonds or ions the atoms may form, so the chemical reactivity of an atom arises from its electron distribution. The properties of compounds emerge from the arrangement of their constituent atoms and of the bonds between them.
Thus, a wide variety of molecules with very different chemical properties can be made from the same basic atoms. Each molecule has a distinctive size, shape, and charge distribution, which determine its highly specific ability to interact with other molecules.
Compounds in chemical wastes may contaminate the environment if their atoms are combined in new arrangements that harm living organisms.
Explanation:
Answer:
A
Explanation:
These are the correct layers in order of increasing altitude.