Answer: crossing over allows for genetic variation
Explanation:
crossing over is the exchange of genes between two chromosomes which ends up resulting in non-identical chromatids that comprise the genetic material of gametes (sperm and eggs).
Basically crossing over makes the chromatids that are held together by a centromere, no longer identical to eachother which creates genetic variation.
Answer:
C & D
Explanation:
C - The Sun has an 11 year solar cycle. When the solar cycle is at a <em>minimum</em>, active regions of the sun are rare and not many solar flares are detected. They dramatically increase as the Sun approaches the <em>maximum</em> part of its cycle.
D - It's the Sun. It's moody. Solar flares are pretty sporadic, they're sudden and often unpredictable.
True, pulmonary arteries carry the blood from the heart, while pulmonary veins return the blood to the heart.