Answer:
C. At least five mass-extinction events have occurred during the last 500 million years.
Explanation:
- The history of mass extinct is related to the five mass extinctions that are caused over by the 350 million years n which many species have disappeared in there short geologic time.
- A massive extinction is caused in the Permian Triassic extinction event i.e about 250 mn years ago which on an estimate has killed 90% of the species.
- The Cretaceous–Paleogene extinction event that occurred over 66 million years ago is known to have wiped out the dinosaurs and many other species.
Answer:
D. the tendency of a cell to maintain a stable internal environment
Explanation:
Meiosis only occurs in reproductive cells, as the goal is to create haploid gametes that will be used in fertilization. Meiosis is important to, but not the same as, sexual reproduction. Meiosis is necessary for sexual reproduction to occur, as it results in the formation of gametes sperm and eggs.
Cellular respiration and photosynthesis are essential to the carbon cycle because cellular respiration involves the intake of oxygen o2 and the exhale of carbon-dioxide co2 into the atmosphere. Where photosynthesis uses the carbon dioxide and water to create oxygen and sugars through energy to repeat the cycle. Respiration in general is a process where carbohydrates are turned into dihydrogen monoxide or water and co2(carbon dioxide). Living organisms together throughout the biosphere and atmosphere work together to continue this because carbon itself is an organic substance.
