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.
One of the challenges that scientists face when classifying a new fossil is that any tiny detail is all that separates one species from another. Further exploration is required to identify another set of characteristics that may help in deciding which organism belongs or create a new class.
Answer:
<em>The correct option is d) an ecotone</em>
Explanation:
An ecotone can be described as an area of transition between two different biomes. An estuary can be described as an ecotone where the river water meets the seawater. The freshwater biome mixes with the seawater biome in an estuary. Unique plants and animals are grown in an estuary which are adapted to live in such an environment. The water present in an estuary is termed as brackish water. Hence, the correct option is d.
Index fossils (also known as guide
fossils, indicator fossils or zone
fossils) are fossils used to define
and identify geologic periods (or
faunal stages).
