What makes a cell membrane waterproof

Potentially, using the genetic code as it exists, nature could have used 63 amino acids. Why do you think it only uses 20?

Assume a molecule must cross the plasma membrane into a cell. The molecule is a very large protein. How will it be transported into the cell? Explain your answer

The cells provide a means of acquiring nutrients in the brain. a. Astrocyte b. Microglia c. Ependymal d. Oligodendrocyte

Dylan drew a diagram showing that certain organisms eat other organisms. The diagram included a caption stating that the amount of available energy decreases with each organism that is eaten.

Which statement is true about crossing over of genes? a. crossing over does not occur between genes that are far apart from each other on a chromosome b. frequency of crossing over is related to the distance between linked genes. c.

How and why do scientists think humans have evolved?

In operant conditioning, many complex behaviors are learned through shaping. T/F

Which is an example of a community? A. one wild turkey B. one group of American robins C. groups of American crows, blue jays, and red oak trees D.

How did Hershey and Chase ""label"" viral DNA and viral protein so that they could be distinguished? Explain why they chose each radioactive tag in light of the chemical composition of DNA and protein.

What can be define Axon term?