<span>Melanin helps protect the skin against effects of the sun such as skin cancers and premature aging. In African American skin, melanin provides a sun protection factor (SPF) equivalent to 13.4 compared to 3.4 in white skin and thus the former have lower incidences of skin disorders associated with exposure to the sun.</span>
Answer:
d) do all jobs for survival
Explanation:
A single cell perform all its activity on its own.
Answer:
Winter has the least amount of day light because the Northern Hemisphere leans away from the sun.
Answer:
Step one: After pollen has landed on the stigma, it grows a pollen tube down through the style to the ovary. Step two: The nucleus of the pollen grain travels down the pollen tube and fertilises the nucleus in the ovule. Step three: The fertilised ovule develops into a seed.
hope it helps.
The right answer is cellulose
Cellulose is a carbohydrate consisting of a linear chain of D-glucose molecules (between 15 and 15,000). This biopolymer is the main constituent of the plant cell wall, including wood (which is also characterized by a high lignin content).
Pectin is also the structure of plant cells, but they are heteropolysaccharides.