the answer would be D. Presence of cell membranes.
A. He should add shells that are different colors, but the same size and type, to the tank and observe which shells the hermit crabs choose.
Durning an experiment you need to keep everything the same but only change the certain things based on your theory.
Such as how the student wanted to see if the color attracted the crab. If he had changed the size and type of the shell then the crab would have chosen the bigger one as they tend to grow into larger shells.
Next, Mendel took the F1 progeny and allowed them to self-fertilize. In the resulting F2 generation, 3/4 showed the dominant phenotype, and 1/4 showed the recessive phenotype. ... 1 out of 3 round pea plants from the F2 generation were true-breeding and produced only offspring with round peas.
Answer:
Skeletal system
Explanation:
the bones of the skeleton protect the internal organs and reduce the risk of injury on impact. For example, the cranium protects the brain, the ribs offer protection to the heart and lungs, the vertebrae protect the spinal cord and the pelvis offers protection to the sensitive reproductive organs.
