A mammals need for oxygen effects their heart rate because there could be some cases where they're in lack of oxygen causing them to be literally ' out of breath ' . Like climbing a mountain. The higher you go the less oxygen.
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B) increases the genetic variability of the offspring because there are more genes presemt
Answer;
-Permitted the evolution of novel forms
Explanation;
-Hox proteins regulate other genes. Hox genes code for proteins that attach to molecular switches on DNA, turning other genes on and off. The DNA-binding piece of a Hox protein is called the homeodomain, and it's encoded by the homeobox.
-Hox genes are important as they help lay out the basic body forms of many animals, including humans, flies, and worms. They set up the head-to-tail organization.
Closed system because I used safari for 5 minutes!
