A movement in response to gravity is called tropism.
Answer:
D) Some kind of exoskeleton, or hard outer covering
Explanation:
Ecdysozoa is a clade of animals that gathers arthropods, nematodes and seven other phyla. These organisms have a type of exoskeleton, or hard outer lining that limits the growth of these animals. At some point in the life of these animals, the "exoskeleton" becomes tight and forces these animals to form a new exoskeleton in order to grow. The process of moving from one exoskeleton to another is called ecdysis and also happens in insects.
Answer:
C - It allows the cell to absorb more water.
Explanation:
Specialized cells often have unique structures that allow them to carry out a function. For example, a root hair increases the surface area of a root epidermal cell, allowing the cell to absorb more water.
Answer:
The codon length would not change.
Explanation:
Codons have 3 bases and normally the DNA has 4, each codon counts for a single amino acid. There are 64 possible codon variations which can be calculated by 
.
If there were 6 bases in the DNA than there would be 
codon variation that correspond to the same 20 amino acids but the codon lengths would still be the same.
I hope this answer helps.
