Answer: It is the indiscriminate dumping of nonuseful substances into water bodies
Explanation:
Water pollution occurs when non-useful substances like chemical, industrial, human wastes etc, are dumped into water bodies (oceans, rivers, lakes) as a means of disposing such wastes
For instance: water pollution occurs when unused battery is drop in the lake, sewage is dumped in the river etc
The correct answer is: A) The polarity of membrane phospholipids
Factors that affect membrane permeability are
1. Chemicals :
Some of the organic solvents such as chloroform and ethanol can dissolve the membrane and thus, destroy the selective permeability of the membrane.
2. Temperature :
Too high temperatures denature the protein that are in the structure of the membrane destroying its selective permeability. On the other hand, too low temperature slows down molecule movements and the permeability decreases.
3. Cholesterol:
Increases the permeability by reducing the barrier formed by phospholipids’ heads
4. The saturation of hydrocarbon tails in membrane phospholipids:
Saturated fatty acids decrease permeability of the membrane because they get very close together, which makes it harder for the molecules to pass through.
Plant cells have a cell wall but animal cells have a cell membrane
Answer:
Pylorus
Explanation:
The stomach is a J-shaped organ which is a part of the digestive system. The digestive system on one end is attached to the oesophagus and on the end to the small intestine.
The pylorus structure of the stomach is composed of thick muscles which help to mix or agitating the food in the stomach and controls the movement of the food to the duodenum which is the first part of the small intestine. The movement is controlled by the ring of muscles in the pylorus called pyloric sphincter.
Thus, Pylorus is the correct answer.
Ribosomes- Organelles that help in the synthesis of <span>proteins.</span>
