Spines primarily have a protective function in plants. The spines can be sharp, and form a physical barrier against herbivores which may want to feed on the plant. Spines however also have other benefits. The spines on a jumping cactus allow segments of the cactus to stick to passing large animals or humans, thereby allowing the cactus to spread to other areas through asexual propagation. Spines are modified leaves, and spines have a much lower surface area than leaves, and therefore can reduce transpirative loss of water by the plant during harsh droughts. Some trees in alpine regions, such as pine trees, have developed spine-like leaves to prevent the accumulation of snow in the branches.
100% of the offspring would have the genotype Bb, and the phenotype of the blue color.
mutation, gene flow and sexual reproduction
If an organism has a mutation, that helps it survive, it will breed and this mutation will keep in the gene pool. Out of all listed choices, the only mutation that will help an organism survive is c). The better a rabbit can hide from predators, the longer it will survive and the more will breed
I would say that the brain stem would automatically send a message to the muscular rib cage & your diagphragm to make them work harder.
Hope this helps :))