Question

Which one is spindle-shaped, mobile with microtubules?
A. Sporont
B. Ookinete
C. Cryptozoite
D. Sporozoite

Answer 1

Hint: Microscopic hollow tubes which are made up of alpha and beta tubulin proteins that are part of a cell’s cytoskeleton are known as microtubules. A network of protein filaments which extends throughout the cell, gives the cell shape and keeps its organelles in place. In the cytoskeleton, Microtubules are the largest structures and are about \[24\] nanometers thick. Microtubules have an important role in cell movement, cell division, and transporting materials within the cells.

Complete answer:
Option A. Sporont: an encysted spore that has been developed from a zygote, which undergoes sporogony to form sporozoites is known as Sporont. These are not spindle shaped.
Hence option A is not correct.
Option B. Ookinete: The motile zygote which forms when microgamete fertilizes the macrogamete during sexual reproduction of certain protozoans such as the malaria causing Plasmodium are known as ookinete. They have a conserved left‐handed corkscrew shape.
Hence option B is also not correct.
Option C. Cryptozoite: These are malarial parasites at the developmental stage in which it inhabits bodily tissue before invading into the red blood cells. They are not spindle shaped.
Hence option C is also not correct.
Option D. Sporozoite: The sporozoites are spindle or sickle-shaped and uninucleate organisms that are capable of wriggling movement. Each of them has a covering composed of elastic pellicle containing longitudinal contractile microtubules.
Hence option D is the correct answer.

Hence, Option D. Sporozoite is the correct answer.

Note:
Sporozoites in Plasmodium are those cells which evolve in the salivary glands of mosquitoes. It leaves the mosquito whilst a blood meal and then proceeds towards the liver cells where they get reproduced. The cells which get infected by sporozoites eventually burst out and release merozoites into the bloodstream of the host. The sporozoites have the ability to move and their movement is brought about by gliding motion.