There have been five mass extinction events throughout Earth's history:
The first great mass extinction event took place at the end of the Ordovician, when according to the fossil record, 60% of all genera of both terrestrial and marine life worldwide were exterminated.
360 million years ago in the Late Devonian period, the environment that had clearly nurtured reefs for at least 13 million years turned hostile and the world plunged into the second mass extinction event.
The fossil record of the end Permian mass extinction reveals a staggering loss of life: perhaps 80–95% of all marine species went extinct. Reefs didn't reappear for about 10 million years, the greatest hiatus in reef building in all of Earth history.
The end Triassic mass extinction is estimated to have claimed about half of all marine invertebrates. Around 80% of all land quadrupeds also went extinct.
The end Cretaceous mass extinction 65 million years ago is famously associated with the demise of the dinosaurs. Virtually no large land animals survived. Plants were also greatly affected while tropical marine life was decimated. Global temperature was 6 to 14°C warmer than present with sea levels over 300 metres higher than current levels. At this time, the oceans flooded up to 40% of the continents.
According to a source, the answer is <u>A. M phase–Cell growth before DNA replication.</u><span>
Mitosis is the cell division that happens in all cells in the human body except sperm and egg cells. They produce diploid cells. Meiosis on the other hand is responsible for the cell division of the gametes, spermatogenesis (sperm cells) and oogenesis (egg cells), such haploid cells. Take for instance your integumentary system, layer of the skin in which your stratum basale always produces new epithelial cells (via mitosis) to take over until the outer layer, called stratum corneum (a continous replaced dead cells in this layer). </span>
Answer:
B
Explanation:
An alkylating agent adds an alkyl group to the DNA strand of a specific cell group highly prone to being cancerous. This action is exactly what Cisplatin does by disrupting DNA replication (mitosis) for cancerous cells by inserting itself into a DNA strand.
