Answer: B) proteins in the membrane act like gates to control entrance and exit of molecules.
Explanation: Plasma membrane is composed of phospholipids bilayer in which the hydrophobic regions of the phospholipids face each other to form the core of the bilayer. Proteins are embedded in the bilayer through an interaction between the amino acid side chains and the nonpolar acyl chains of the phospholipids. The embedded membrane proteins form channels for passage of ions and other molecules. Each membrane protein is selected for one or more ions or molecules that passes through it. The membrane is said to be semipermeable because it allows the passage of some molecules and excludes the passage of others.
A. arteries and veins.
Just as tubes within the stems and leaves of plants transport water, arteries and veins within animals transport blood with the required nutrients for our bodies.
(True) because i remember this question very well.
Answer:
here is your answer
Explanation:
In biology, a population is a number of all the organisms of the same group or species who live in a particular geographical area and are capable of interbreeding
Answer:
The frequency of the recessive allele which codes for grey pelt character will rise above 20%, while the that of the dominant allele that confers brown pelt character will decrease below 80%.
Explanation:
Since the population of foxes with brown pelts are being selectively hunted by humans, the population of foxes with brown pelts will keep reducing while the population of foxes with grey pelt will thrive in its place.
<em>Hence, the the frequency of the recessive allele which confers grey pelt attribute will rise above original 20% within the population, while the dominant allele will decrease below 80%.</em>