Answer:
A. insects fly around a bright lamp at night
Explanation:
insects are naturally attracted to light due to presence of positive phototaxis. Insects revolve around the light in the same way as electrons do around the nucleus.
A single base-pair deletion would cause a frameshift mutation, disrupting every codon sequence read after it. A single base-pair change, however, only affects one codon. It is therefore less likely to cause harm.
D marks the structure formed from the zygote.
