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Agriculture · Q262

Agricultural Entomology

Graduate and Post Graduate · Agriculture · question 262

Q262

In collembolans, eggs are

A.
Isolecithal and holoblastic
Answer
B.
Isolecithal and heteroblastic
C.
Heterolecithal and holoblastic
D.
Heterolecithal and heteroblastic

Answer: Option A

Solution

Answer: Option A
Solution:
In collembolans, eggs are Isolecithal and holoblastic.
Springtails (Collembola) form the largest of the three lineages of modern hexapods that are no longer considered insects.
Collembolans are omnivorous, free-living organisms that prefer moist conditions. They do not directly engage in the decomposition of organic matter, but contribute to it indirectly through the fragmentation of organic matter and the control of soil microbial communities.
These eggs have sparse, equally spaced yolk and are thus isolecithal (“equal yolk”). In these species, cleavage is holoblastic (holos, “complete”), meaning that the cleavage furrow extends through the entire egg.