The branch of biology that deals with the relations of organisms to one another and to their physical surroundings.
D. The macronucleus does not disintegrate during conjugation.
The macronucleus contains the working copies of genes needed to support an enormous cell. It is formed by a division of the fused diploid nucleus after conjugation followed by multiple rounds of internal gene replication which does not occurs in the micronucleus.
B. They decrease. As more we use the sources of nature, the less is left.
