D) new plant species competing with native plants
Answer;
both positive and negative
Explanation;
-The elephant are keystone species, playing an important role in maintaining the biodiversity of the ecosystems in which they live. They may have both negative and positive interactions to the environment. For example, during the dry season, elephants use their tusks to dig for water, which has a positive impact to the surrounding.
-They clear large amounts of vegetation, which removes habitats for some organisms but makes the area inviting for other organisms. This has both positive and negative impact to the ecosystem.
Answer: C) ciliates.
Explanation: Ciliates possess two different nuclei a diploid micronucleus which carry the germline of the cell. It also has a large, polyploid macronucleus which can be termed the vegetative nucleus, it takes care of general cell regulation, it expresses the phenotype of the organism. The macronucleus is generated from the micronucleus. The micronucleus passes the genetic material to offspring, but it does not express its genes. The macronucleus provides the small nuclear RNA for vegetative growth.
<span>hybridization can be used to produce plants giving a high yield by breeding an indigenous variety of the plant having disease and pest resistant qualities and also a greater adaptability to the particular environment with a high yielding exotic variety to get an offspring having the desired qualities of both and also promoting hybrid </span>
