Answer:
The extinction of a large number of species within a relatively short period of geological time.
Answer:
Four innovations are central nervous system, eyes, bilateral and hermaphrodites.
Explanation:
Innovations found in an ancient flatworm were the presence of central nervous system means head and a brain. The head had eyes which is the first in the animal world. Their body is bilateral means equally divided into two parts. They are also hermaphrodites means having male and female on a single organism which was not present at that time of animals.
Answer:
Growth factors
Explanation:
Growth factors, unlike hormone, have an influence on most cells on the body. They promote cell division and differentiation. Therefore, they are significant in promoting the cell cycle. Therefore, they should be able to be recognized by checkpoint proteins that regulate the cell cycle by either promoting progression or arresting the cell cycle.
Natural selection is the differential survival and reproduction of individuals due to differences in phenotype. It is a key mechanism of evolution, the change in the heritable traits characteristic of a population over generations.
The cells show characteristics of tumors.
Tumor cells have the ability to grow and proliferate in absence of adhesion or anchoring. This is particularly helpful during metastasis when a cancer cell travels through the bloodstream to another location.
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A cancerous cell has a number of mutations that regulate cell division. In addition, they exhibit impairment in DNA repair system. Therefore, cancer cell divided fast. Since the DNA repair system is nonfictional, the cells do not pause division to repair the mutation.</span>
