Answer:
A) they help transport some substances through the membrane.
Explanation:
The membrane proteins that span the bilayer of phospholipids help in the transport of polar, large and charged substances across the membrane. The nonpolar core of the membrane does not allow these charged and polar substances to pass through. Proteins serving as channels form pores to allow movement of the specific substances.
On the other hand, carrier transport proteins of the membrane bind to the substances present at one side of the membrane and deliver them to the opposite side.
The parts of the alimentary canal listed in order are the mouth, pharynx or throat, esophagus, stomach, small intestine and large intestine. The alimentary canal is the digestive system and includes the parts of the body with which food comes in contact from eating to waste elimination.
Carbon dioxide and water (and sunlight)
Answer:
The variation might occur in the population that leads to the evolution of the species. This variation may occur due to natural selection, mutation or recombination.
The variation might change the genotype and allelic frequency of the population and might also change the phenotype of the individual in the population. The breeding adults of the left mouthed in 1981, 1987 and 1990 shows variation and was equally opposite phenotype which is more common in the population.
Answer:
Explanation:
Oil sand is an unconventional source of oil. It requires specialized technology and great expertise to win oil from associated waste materials.
The reason why some companies bother about such oil source is explained below;
- Prevailing cost of oil in the world market makes it profitable to extract these oil from sands. A high cost of oil crude oil is a good cause to produce oil form oil sands.
- Development of new technology can catalyze interest in profitable exploration from unconventional sources.
- Economic policies can also favor the production of this source of oil.
- Demand for oil in the market can jack up production levels that can also be met by oil from oil sand.
