The elodea is getting the carbon dioxide from its environment like when underwater animals breathe out carbon dioxide the plants will use that carbon dioxide. The plants can also get the carbon dioxide from the atmosphere which can "dissolve" in water.
Answer:
Each year, earthworms move deep into soil during fall and winter and return toward spring and summer. The likely stimulis for this behavioral response are relative humidity & temperature. Since the nematode breathes via the skin, the mucus coating may become dry & the organism would die if exposed to extreme cold & dryness.
Explanation:
Answer:
Option A, a compound that contains carbon atoms bound to other elements
Explanation:
An organic compound is one which has at least one carbon atom that is bonded to several other atoms (may be metallic or non metallic) by a single or double bond is termed as organic compound . The most common atoms with which carbon forms bond are hydrogen, nitrogen,and oxygen.
Some common examples are -
Methane - 
Methanol - 
Hence, option A is correct
A cell membrane protects a cell from it's surroundings. The cell membrane controls the movement of substances from the outside and inside of cells and organelles.
