Question

Shell coiling in Limaea (shell) is an example of
A. Maternal inheritance
B. Biparental inheritance
C. Daueromodification
D. None of the above

Answer 1

In numerous univalve and bivalve mollusks (Mollusca), the shells are coiled. The condition is generally observable among gastropods (Gastropoda) and cephalopods (Cephalopoda), where the shell is an empty cone, coiled up to a more prominent or lesser degree. These moved up cones develop at the apertural end just and structure a logarithmic winding. Since the shell is an empty cone, coiling about a vertical pivot and developing at the aperture end.

Complete answer:
-The female gamete contributes cytoplasm to the creating incipient organism. Hence, the characteristics constrained by qualities present in cytoplasm follow maternal inheritance. So, option A is correct.
-A biparental inheritance incorporates Mendelian inheritance where the posterity acquires a maternal and a fatherly allele of a quality. So, option B is incorrect.
-Dauermodification alludes to a procured character that is communicated through the cytoplasm to posterity yet is certainly not a lasting heredity characteristic. So, option C is incorrect.
-Shell coiling in snail is constrained by D (dextral) and d (sinistral) alleles. The genotype of offspring relies upon the genotype of the mother. If the mother is "DD", the Dd posterity is dextral however the "Dd" offspring of the "dd" mother has sinistral coiling.
Hence, the correct answer is option A.

Note: Inheritance relying on implication upon atomic qualities and including no referred to cytoplasmic here­ditary units is portrayed as maternal impacts. Such instances of maternal impacts can be recognized from those, where extra-chromosomal or cyto­plasmic innate units are available. The inheritance of characters constrained by the qualities is identified with the chromo­somes of the core. These qualities, which ear­lier assigned as variables by Mendel, follow an unmistakable example of inheritance as articulated in Mendel's laws.