An endospore may survive a drought because it is protected by a
a. hollow bridge. b. thick wall. c. plasma membrane. d. plasmid replication.

b. thick wall.

Explanation:

Endospore is a structure formed by some bacteria, that help them survive unfavourable conditions (e.g. lack of nutrients). This survival strategy of some bacteria (usually Gram+ bacteria) help them stay dormant for a while, until stressful conditions stop. A thick wall composed of many layers (exosporium, spore coat, spore cortex, core wall) of the endospore is what provides resistance to different stressful chemical and physical factors such as UV radiation, temperature, chemical damage etc.

tsd is temerature dependent sex determination.

tsd: it is a type of environmental sex determination in which the temperature experienced during embryonic/ larval development (ambient temperature for development) determine the sex of the offspring.

crocodile displays the tsd where the ambient temperature of the developing egg determines the individual's sex. for example in the american alligator's eggs, incubation at 33 ºc produces mostly males, while incubation at 30 ºc produces mostly females. so if the american alligator's egg will get the ambient temperature (33 degree celcius)during embryonic development from egg, the offspring will be male and same for the female sex determination.