Answer:
The CNS
Explanation:
First, the entire CNS is enclosed in bone. The brain is protected by the skull, while the spinal cord is protected by the vertebra of the spinal column. The brain and spinal cord are both covered with a protective tissue known as meninges.
Answer:
The duplication of a cluster of four Hox genes is equally likely as the duplication of a single Hox gene.
Explanation:
This comes from the definition of the parsimony principle, which is the action of choosing the simplest scientific explanation fitting the given evidence, meaning that all other elements are equal when evaluating the hypothesis. In biology the best hypothesis is the one that requires the fewest evolutionary changes.
Since three independent duplications of an individual Hox gene is in evolutionary terms, more complex than a single duplication or a cluster, then that hypothesis would be the most parsimonious.
Population growth is the change in the number of INDIVIDUALS in a population over time.
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Answer:</h3>
Vertebrates have backbones, while invertebrates do not.
Humans, for example, are vertebrates because we have backbones.
