The fossil record of Antarctica shows the presence of tropical plants, such as one particular species related to the present day breadfruit. Most plants cannot survive in prolonged temperatures of less than 6 degrees Celsius. Antarctica is freezing all year round and could only have supported tropical and sub tropical plants if it was once much closer to the equator.
The presence of fresh water species also suggest that the continent was closer to the equator. Antarctica is frozen solid with a thick ice sheet.....rivers would be frozen solid all year round or would be limited to water movement under glaciers that melt as a result of pressure and friction. This environment is not suitable to support large fresh water organisms.
Answer: adjective. Botany (of an ovary) having two carpells.
Answer:
The sun's solar radiation and the wind's movements.
Explanation:
The heat from the sun and air movement is responsible for the weather on Earth. All-weather takes place in the lowest layer of the Earth's atmosphere, which is a gaseous layer that surrounds the planet. The heat of the sun causes the air in this layer to warm to various temperatures in different regions.
Answer: An area with lots of different kinds of plants and animals.
Explanation:
ANSWER:
Most types of cancer are believed to begin with a random genetic mutation. This is followed by mutations, which endow the cancer cells with properties allowing them to grow without normal controls to become a tumor.
Mutation is any change in the DNA sequence of a cell. Mutations may be caused by mistakes during cell division, or they may be caused by exposure to DNA-damaging agents in the environment.
Genetic Mutations that lead to cancer cell formation can occur in two forms:
1. GROWTH-PROMOTING GENES are commonly mutated in cancer cells, becoming SUPER-ACTIVE and producing cells that are too strongly stimulated by growth receptors.
2. Mutations can INACTIVATE the genes that suppress cell proliferation or those that signal the need for apoptosis. These genes are known as TUMOR SUPPRESSOR GENES.
