Answer:
The water molecules move by active transport into the cell from low water concentration to high water concentration
39
Reproductive cells are haploid (have 1/2 the chromosomes), whereas somatic/body cells are diploid (have the full set of chromosomes)
This makes sense if you think about it. Using the example from the question, every dog has 78 chromosomes. This includes two of each (there are two chromosome 1's, two chromosome 2's, etc. This is visible in the karyotype attached). One set of these chromosomes were inherited from the mother, and one set from the father. Each parent contributed 39 chromosomes (one chromosome 1, one chromosome 2, etc.). If the dog in the question were to have 78 chromosomes in its sperm cells, it would contribute two sets to its offspring. When combined with the chromosomes in the egg cell, the offspring would end up with extra chromosomes. Therefore, both the sperm and the egg cells will have 39 chromosomes, one of each. When combined, they will produce offspring with 78 chromosomes, the proper number.
Answer:
The voltage-gated potassium channels associated with an action potential provide an example of what type of membrane transport?
A. Simple diffusion.
B.<u> Facilitated diffusion.
</u>
C. Coupled transport.
D. Active transport.
You are studying the entry of a small molecule into red blood cells. You determine the rate of movement across the membrane under a variety of conditions and make the following observations:
i. The molecules can move across the membrane in either direction.
ii. The molecules always move down their concentration gradient.
iii. No energy source is required for the molecules to move across the membrane.
iv. As the difference in concentration across the membrane increases, the rate of transport reaches a maximum.
The mechanism used to get this molecule across the membrane is most likely:
A. simple diffusion.
<u>B. facilitated diffusion.
</u>
C. active transport.
D. There is not enough information to determine a mechanism.
Carrier proteins - exist in two conformations, altered by high affinity binding of the transported molecule. Moves material in either direction, down concentration gradient (facilitated diffusion). EXAMPLE: GluT1 erythrocyte glucose transporter.
Channel proteins - primarily for ion transport. Form an aqueous pore through the lipid bilayer. May be gated. Moves material in either direction, down concentration gradient (facilitated diffusion). EXAMPLES: Voltage-gated sodium channel, erytrhocyte bicarbonate exchange protein.
This might be helpful... because I don't know anything about facilitated diffusion.
Answer:
B
Explanation:
I learned this 2 years ago
