Question

Shell coiling in limnaea is an example of
A. Maternal inheritance
B. Biparental inheritance
C. Predetermination
D. Dauermodification

Answer 1

Hint: Shell coiling in limnaea is an example of extranuclear inheritance. Extranuclear inheritance is the transfer of genes that occur outside the nucleus. It is found in most eukaryotes and is known to be found by cytoplasmic organelles such as mitochondria and chloroplasts, viruses or bacteria.

Complete answer:
Let’s first study all the points one by one for answering the question.
Maternal inheritance-Because extranuclear DNA is expressed in the egg during fertilization, offspring traits are a form of inheritance that comes from the mother. This is because the eggs retain their mitochondria. Example-Shell coiling in limnaea. Offspring that indirectly depend on nuclear genes and do not include hereditary cytoplasmic units are known to be described as a maternal effect. Such cases of maternal effect can be distinguished from cases in which hereditary units of extra chromosomal or cytoplasm are present and function independently of each other or in cooperation with the nuclear genetic system.
Biparental inheritance-This type of Inheritance occurs in extranuclear genes when both parents donate organelle DNA to their offspring. It may be less common than allogeneic extra-nuclear inheritance and usually only occurs in an acceptable form for a short time. An example of the inheritance of adoptive parents in mitochondria is the yeast Saccharomyces cerevisiae.
Predetermination-The original definition is the effect of the maternal gene on inheritance through the cytoplasm of the egg without including the plasma gene.
Dauer Modification-Permanent transformation is a phenotypic change caused by chemicals and other environmental factors that persists for several generations and travels through the cytoplasm of the egg.
So, the correct answer is “Option A”.

Note:
The Limnaea peregra also known as water snail has two types of spiral shells: right or dextral which is controlled by the dominant D allele) and the second is sinistral which is controlled by the double recessive d allele). However, the shell of the offspring is packaged according to its effect on the mother's cytoplasm. For example, the intersection of DD (father) and dd (mother) gives Dd but has a left winding.