1) Which of the following activities would employ isometric contractions? a) Flexing the elbow
b) Chewing food
c) Maintaining an upright posture
d) Running
e) Writing

c. Maintaining an upright posture

Explanation:

"Isometric contraction" is all about increasing the tension in the muscles without shortening or lengthening the length of the muscles. There's also no movement.

Among the choices above, it is only "Maintaining an upright posture" that doesn't have movement; therefore, this employs the isometric contraction. This kind of contraction increases a person's strength. Another example of this contraction is holding a weight overhead.

answer; i believe that the correct answer is (light);

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.