Answer:
Which of the following groups of animals has suffered the largest percentage of known extinctions in the last 400 years? Mammals
Explanation:
Changes to habitats and poor reproductive trends are among the factors that can make a species’ death rate higher than its birth rate for long enough have eventually lead to the extinction of mammals in the world.
<span>Cells control cell division in order to maintain normal cell function. If something happens to the control of the cell division, the healthy cells will divide uncontrollably. These new cells are cancer cells. </span>
The mutations in three genes are responsible for development of cancers:
1. Mutation in proto-oncogenes. Proto-oncogenes normally signal cells to grow and differentiate. Proto-oncogenes can become oncogenes due to mutations which result in the uncontrollable division of the cells.
2. Mutation in tumor suppressor genes. In normal cells, tumor suppressor genes suppress genes essential for cell cycle and that way they prevent uncontrollable cell division. However, after a mutation in these genes, suppression is lost and the cell may progress to cancer.
3. Mutation in stability genes. In normal cells, they have no role either in cell death or growth, but they control mutation rate. Mutation in stability genes results in situation where all genes, including proto-oncogenes and tumor suppression genes, are more frequently mutated.
Answer:
It can be characterized by the extreme heat or too much rainfall. Deforestation also degrades soil quality and is a major cause of the world's rapid desertification. Such weather patterns and environmental changes contribute to the plummeting of the agricultural production.
Explanation:
Answer:
A. Species that remained after the extinction were able to radiate, new adaptations arose, and these adaptations produced the diversity seen today.
Explanation:
When species went extinct they also left niches that could be occupied by "new" species; new places to live, places to be filled in the food web and different relationships to be formed. The wide availability of resources made organisms to radiate leading to a "new" diversity of shapes, sizes, and lifestyles.
B. Species that have gone extinct were able to re-evolve from the ancestors that survived the extinction. If you are extinct you are gone forever.
C. Species that remained after the extinction were unable to speciate. Therefore, the number of species on Earth today is lower than the number of species present just before either extinction. The fossil record proves that species have changed over time and the diversity has changed over the history of Earth.
D. Species that remained after the extinction represented all of the lineages that were present before the extinction event. Therefore, extinction did not change the diversity of lineages. Again, the fossil record is evidence that lineages have changed over the history of the Earth.
1. Nothing he is a lie
2. B.
3. Nothing is an advantae.
4. c
5.d
