Question

Shell coiling in Limnaea is an example of
A. Maternal Inheritance
B. Biparental Inheritance
C. Predetermination
D. Dauer- modification

Answer 1

Hint: There are some factors or traits inherited from a source other than the nucleus. They are known as cytoplasmic factors and also known as ‘Extra nuclear’ or ‘extra chromosomal’ inheritance or also as ‘maternal inheritance’. Cytoplasmic DNA exists along with functions as information carrying genetic material.

Complete answer:
> Option A- Some of the factors or traits are inherited by the offspring which can be solely attributed to the genetic material transmitted that is by the mother to her baby. It occurs during the union of gametes the ovum retains its mitochondria.

> Option B - Normal mendelian inheritance that is the progeny inherits a maternal along with a paternal allele of a gene is known as Biparental inheritance. It is the type of extranuclear inheritance, in which both parents contribute traits to their offspring.

> Option C - Predeterminism term can be used to define a pre-established causal determinism, in this case it is categorised as a specific type of determinism.

> Option D- Dauer modification is an acquired character transmitted through the cytoplasm to further succeeding generations but it is not incorporated into any permanent heredity of the strain.

Hence, the correct answer is option (A).

Note: Maternal influences are detected from the point of reciprocal cross in a species. For instance: Coiling in snails. Water snail Limnaea – are species where shell coils to right that is dextral) as well as some other where shell coils to left that are sinistral. Few of them show both, where the mothers control it.