?????????????? I am just elementary why are you asking me I took my parents email anyway
Answer:
The answer is double helix.
Explanation:
In its natural state, each DNA molecule is actually composed of two single strands held together along their length with hydrogen bonds between the bases. Watson and Crick proposed that the DNA is made up of two strands that are twisted around each other to form a right-handed helix, called a double helix.
Hope this helps!! ;)
Respiratory- You breath faster to help supply the muscles with more oxygen.
Integumentary (skin) - Sweat helps cool down the body.
Answer:
its either A or D I think that it's a but im not 100%sure