The structure of a dna molecule resembles the shape of a twisted ladder. in this model, which part of the ladder is made of sugars and phosphates?

Plzz hurry im being timed during times of vigorous physical activity, muscles require a constant supply of oxygen. how does the body respond to these needs? a. breathing rate and heart rate both decrease. b. breathing rate and heart rate both increase. c. heart rate decreases, but breathing rate remains stable. d. breathing rate increases, but heart rate remains stable.

This is the main structural axis of the plant that supports leaves, flowers and fruits; transports fluids; stores nutrients and produces new tissue.

Sequence how oxygen accumulated in the atmosphere and the effect it had on life by completing the flowchart