First nucleus in pollen grain divide to form generative nucleus and tube nucleus. the generative nucleus divide to form two sperm nuclei, while tube nucleus help in the development of pollen tube.
Elevated carbon dioxide levels may mitigate losses of biodiversity from nitrogen pollution. ... Rising levels of carbon dioxide may overheat the planet and cause other environmental problems, but fears that rising carbon dioxide levels could directly reduce plant biodiversity can be allayed, according to a new study.
Answer:
Because humans has not arrived until 20,000 years ago.
Explanation:
The genus homo has been taken to the emergence with the Homo habilis. Homo sapiens has been emerged around 300,000 to 200,000 years ago.
Holen and colleagues in 2017 discovered 130,000-year-old site in California that contain a a mastodon that had been butchered by humans. Some scientists express skepticism because it has been believed that only humans have occupied North America. The Homo sapiens has not arrived until 20,000 years ago.
Answer;
It is slowed down dramatically
Explanation;
-The myelin sheath can be described as an insulating layer that is composed of wrappings of the plasma membrane of glial cells that encloses the axons outside the brain and spinal cord. It is a fatty material that coats, protects, and insulates nerves, enabling them to quickly conduct impulses between the brain and different parts of the body.
-In multiple sclerosis the T cells either partially or completely strip the myelin off the fibers, leaving the nerves unprotected and uninsulated. These nerves are not as able to pass messages from the brain to the other body parts. The messages the nerves try to send are delayed or distorted and the messages the brain receives may be misinterpreted.
Answer:
ribosomes and cell membrane
Explanation:
Prokaryotes are not allow to have nucleus. They have free roaming DNA, so only ribosomes and cell membrane can be both.
