The stigma of the flower must be elevated (by the style) away from the ovary to avoid self pollination or contamination. The stigma is covered with sticky substances so that pollen can easily attached themselves to it.
It's called a nutrient.
Nutrients are well, something that all humans need to survive. A certain amount of nutrients keep humans alive and healthy, yet a lack of nutrients will cause them to become sick and slowly die.
Thus, making it so nutrients is a chemical substance that organisms require to live.
Hope this helps!
Answer:
The correct answer is option A. "Advantageous alleles do not arise on demand".
Explanation:
One of the most common misconceptions of how evolution occurs is that an organism is able to develop advantageous traits on demand. Believing that, for instance, a giraffe was able to develop a large neck because it wanted to reach large trees. This is wrong, evolution is the product of nature selecting random mutations that are advantageous to a species.
The benefit that small spaces provide in the formation of organic molecules is that it creates an additional surface area on which reactions can take place. A larger surface area allows biochemical reactions to take place more frequently, thus increasing the rate of the biochemical reaction.