Answer:
c. Leukocytes (white blood cells)
Explanation:
When they do, so-called daughter cells are generated that have receptors identical to those found on the original lymphocytes. The result is a family of lymphocytes, called a lymphocyte clone.
Amphibians usually have lungs but they can also absorb oxygen through their moist skin. Their body temperature also varies according to their surroundings. Amphibians also reproduce by external fertilisation and lag eggs.
Answer:
Earth's temperatures increased, causing widespread evaporation. Earth collided with a large object, forming the moon. Single-celled organisms released oxygen into the air when they photosynthesized.
Carbon dioxide is produced by the burning of fossil fuels. Carbon dioxide is produced by man-made machines. Carbon dioxide is produced by animal agriculture. Hope this helped or helped you get the right idea :p