Viruses can only reproduce by infecting living cells
Answer:
Excretion
Explanation:
The excretory system removes cellular wastes and helps maintain the salt-water balance in an organism. When cells break down proteins, they produce nitrogenous wastes, like urea. The excretory system serves to remove these nitrogenous waste products, as well as excess salts and water, from the body.
It was developed by scientists throughout history of mankind
Answer:
C
Explanation:
They all live in the water
Answer:
The yellow leaf was not exposed to the sun so it can't produce sugar.
Explanation:
The yellow region of the leaf didn't produce sugar because it wasn't exposed to sunlight. Part of the leaf was exposed to the sun, thus this leaf produced sugar, while the yellow part of the leaf did not because it was not exposed to the sunlight.
