Question

Neoteny refers to
A. Development of gonads
B. Moulting
C. Metamorphosis
D. Retention of larval traits in the adult body

Answer 1

Neoteny is defined as a type of paedomorphosis or retention of ancestral juvenile features in descendant adults of a lineage. It is one of the key kinds of heterochrony that has helped researchers to find out about how shifts in development result in macro-evolutionary change.

Complete answer:
The concept of neoteny may be a valuable tool in developmental biology and comparative studies. However, it doesn't explain the potential function of continuous radial growth, it rather suggests that this growth is without biological significance, although it doesn't exclude the likelihood that individuals who have larger bones may benefit in a way from this characteristic.
Neoteny in humans is the slowing down of the body's development. The neotenic changes are sometimes caused by sexual selection in human evolution. Some evolutionary theorists have proposed that neoteny was a key feature in human evolution.
A large number of insects exhibit pedogenesis, and reach sexual maturity during the larval stage but don’t metamorphose into adult form.
Neoteny is additionally observed in domesticated animals like dogs because there are more resources available, less competition for those resources that permits an animal to use less energy in obtaining those resources which further allows them to mature and reproduce more quickly than their non-domesticated counterparts. Another explanation for neoteny in domesticated animals is behavioral characteristics. Behavior is linked to genetics which means when a behavioral trait is chosen for, a physical trait may additionally be selected for mechanisms like linkage disequilibrium. Often, juvenile behaviors are selected for so as to more easily domesticate a species; aggressiveness in certain species comes with adulthood when there's a desire to compete for resources. If there's no need for competition, then there's no need for aggression. Selecting for juvenile behavioral characteristics can result in neoteny in physical characteristics.
Neoteny has been observed in several other species still. Neoteny is subdivided into partial and full neoteny. Partial neoteny is the retention of larval form beyond the standard age of maturation with the likelihood of the event of sexual organs progenesis, but eventually the organism still matures into the adult form. Full neoteny is seen in ambystomatid which remains in its larval stage for the duration of their life.

Therefore, the correct option is D, retention of larval traits in the adult body.

Note:
Sometimes neoteny is also observed in cell organelles. It was observed that subcellular neoteny may help in explaining why sperm cells have atypical centrioles. One among the two sperm centrioles of dipterous insects exhibits the retention of “juvenile” centriole structure, which may be described as centriolar “neoteny”. Typical centrioles form via a step by step process during which a cartwheel forms, then develops to become a procentriole, and further matures into a centriole. The neotenic centriole of pomace fly resembles an early procentriole.