Answer:
via hydrogen bonds; there are two between adenine and thymine and three between cytosine and guanine
Answer: A. A blockage in the aorta
Explanation:
A heart attack happens when one or more aorta or coronary arteries get blocked. With the passage of time, the coronary artery becomes narrow that is because of the deposition of various substances such as fat, cholesterol and other reserves. This restricts the smooth circulation of blood hence results in heart attack or heart stroke.
I will answer the question accordingly so that it help you under stand it better.
Question A.
During an extreme heat wave, plants with white flowers survive better.
What mechanism is in work here?
Answer: Mechanism of Natural Selection
will work here. This is called survival of the fittest which means the best color which fits in harsh conditions will dominate over others and will survive for longer time.
What is the effect on the gene pool?
Answer: The Frequency of white allele will increases
because white color is the best fit to extreme heat wave.
Question B.
A person uproots the five closest plants, which all happen to have white flowers.
What mechanism is in work here?
Answer: The mechanism of gene flow will work here as color of flower represents genotype of flower.
What is the effect on the gene pool?
Answer: The Frequency of white allele will increases because genotype of white flowers is increased.
