The answer is letter D. The macronucleus is not exchanged during conjugation. <span>It normally contains the working duplicates/copies of genes necessary to support an enormous cell. Macronucleus is formed by a direct division of the polyploid nucleus right after conjugation then followed by series of internal gene replication that is not oftenly occurring in micronucleuse.</span>
Answer: Water can hold an unlimited amount of oxygen.
Explanation:
Water cannot hold an unlimited amount of oxygen because it would get to a point where it is saturated as it needs to hold Hydrogen as well. Air on the other hand, has significantly more space for oxygen as it contains only 21% and can keep taking more.
Underwater organisms need oxygen for respiration and a small decrease in the oxygen available in water affects aquatic life because they rely on it to survive.
Answer:
a closed circulatory system.
Explanation:
an earthworm circulates blood exclusively through vessels.
Answer: Racial classification
Explanation: Racial classification can be defined as the way humans are classified based on their physical and social traits which they have such as how they look, their skin color, hair texture, the native languages they speak.
Scientists used racial classification to learn how unique and different humans are.
Answer: C- The atoms have different atomic numbers
Explanation: