<span>B is the correct answer. Multicellular organisms, as with almost all organisms, begin life as a single cell. The increase in the number of cells can be as a result of cell division or cells combining together. </span>
Answer:
50%
Explanation:
According to the given information, the allele for the red-green colorblindness is inherited in an X linked recessive manner. Let's assume that the allele X^c is responsible for red-green colorblindness. The woman is normal but had a colorblind father (X^cY). Fathers give their X chromosomes to the daughters while their Y chromosome is transmitted to their sons. The sons get their X chromosomes from the mother.
The colorblind father has transmitted the X-linked allele for the red-green colorblindness to his daughter. Therefore, the genotype of the woman is X^cX. The woman would produce two types of eggs: 50 % with X^C and 50% with X. Therefore, 50% of sons of this woman would get X linked allele for the red-green colorblindness and would be affected by the disorder while the rest 50% of her sons will be normal.
Explanation:
Answer:
For the complete encyclopedic entry with media resources, visit: http://www.nationalgeographic.org/encyclopedia/weathering/
Weathering describes the breaking down or dissolving of rocks and minerals on the surface of the Earth. Water, ice, acids, salts, plants, animals, and changes in temperature are all agents of weathering.
Once a rock has been broken down, a process called erosion transports the bits of rock and mineral away. No rock on Earth is hard enough to resist the forces of weathering and erosion. Together, these processes carved landmarks such as the Grand Canyon, in the U.S. state of Arizona. This massive canyon is 446 kilometers (277 miles) long, as much as 29 kilometers (18 miles) wide, and 1,600 meters (1 mile) deep.
Weathering and erosion constantly change the rocky landscape of Earth. Weathering wears away exposed surfaces over time. The length of exposure often contributes to how vulnerable a rock is to weathering. Rocks, such as lavas, that are quickly buried beneath other rocks are less vulnerable to weathering and erosion than rocks that are exposed to agents such as wind and water.
For example, certain kinds of air pollution increase the rate of weathering. Burning coal, natural gas, and petroleum releases chemicals such as nitrogen oxide and sulfur dioxide into the atmosphere. When these chemicals combine with sunlight and moisture, they change into acids. They then fall back to Earth as acid rain.
The exoskeleton is made of <span>chitin</span>
Answer:
The correct answer is option b. "by their dominant processes that formed them".
Explanation:
Mountains are classified in four different types according to the dominant processes that formed them. The four different types of mountains are: upwarped mountains, fault-block mountains, folded mountains and volcanic mountains. Upwarped mountains are produced by a differential of pressure from inside the Earth that pushed the crust upwards. Fault-block mountains were formed by tectonic plate movement, folded mountain when two plates move together, while volcanic mountains are formed by a crack in the Earth known as volcanic vent.
