The sac that regulates the temperature of the testes is the ___________.
Scrotum
Answer:
A signal molecule must bind to its receptor to initiate a response. Receptors are proteins that bind to their signal molecule either externally (cell-surface receptors) or internally (nuclear receptors) within the cytoplasm or nucleus. ... Once a ligand binds to its receptor, a series of reactions are initiated.
Explanation:
When talking about evolution, a good example is bacterial resistance to antibiotics.
We start with a bacteria colony, and in contact with antibiotics, most of them die.
Some of them in the colony do not die and took that antibiotic to create a mutation of its DNA to be resistance to that.
They evolved survive that antibiotic.
Answer:
natural selection
Explanation:
According to the evolutionary theory, natural selection can be understood as the process of differential survival and reproduction of individuals due to phenotypic differences, which may be associated with different colors, sizes, behaviors, etc. The only prerequisite is that these phenotypic differential traits must be heritable, which means that they must be passed by genes from one generation to the next. For example, in the white-throated sparrow, it has been discovered two morphs that differ in behavior due to a chromosomal inversion in sex chromosomes.
