Directional selection is where one phenotype is favored, so an example would be "a population of madagascar hissing cockroaches suffers heavy predation from lizards. Because their heads are small, the lizards are unable to eat the very largest adult cockroaches, and instead prey upon small and medium sized adults, so as a result the large cockroaches are favored and live".
Meanwhile, disruptive selection is where both extreme phenotypes are favored, an example would be "a population of rabbits can have black fur, white fur or grey fur. This population of rabbits lives in an area of white rocks. When a local volcano erupts, black volcanic rock now dots the landscape amongst the white rocks. Now the black and white rabbits live longer because the black and white spots on the landscape camoflauge them. The two extreme phenotypes are being favored."
Answer:
Trans-membrane proteins.
Explanation:
Membrane proteins are proteins that are found in the cell membranes of living organisms.
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Answer:
Xylem carries water and minerals from the roots to the leaves. Whereas, phloem carries the food prepared by the leaves to different parts of the plant.
Explanation:
Answer:
Water vapor is a greenhouse gas, which absorbs the heat radiated from the earth's surface. It allows less heat to escape back to space by trapping the heat energy in the lower atmosphere and keeps the atmosphere warm.
Explanation:
Water vapor is formed through a process called evaporation. In this process, water from the ocean, rivers, and lakes evaporates to become water vapor using the energy from the sun. Water vapor also moves into the atmosphere by transpiration (plants) and sublimation (snow and ice).
The water vapor cools down and transforms into water droplets by a process called condensation, as it rises high in the atmosphere where the air is cooler. This water droplets that formed by condensation make up clouds.
When the earth’s surface get heated by the sunlight, some of the heat radiates back into the atmosphere and most of this heat is absorbed by gases in the atmosphere called green house gases. This process is called greenhouse effect, which keeps the earth warm. The green house gases mainly consists of carbon dioxide and water vapor. Water vapor absorbs the heat radiated from the earth's surface. It allows less heat to escape back to space by trapping the heat energy in the lower atmosphere and keeps the atmosphere warm.
The amount of water vapor in the atmosphere is directly proportional to the temperature. When addition of the other greenhouse gases causes a temperature increase (such as extra CO2 from fossil fuels), more water evaporates and this leads to an increase in water vapor which further increases the atmospheric temperature since water vapor is a greenhouse gas. So, water vapor is part of a positive feedback system.
