Answer ASAP:
What happens when a muscle contracts?

A.) Calcium combines with ATP to produce sarcomeres.
B.)Calcium produces contractions.
C.)Myosin heads attach to and pull on a series of actin-binding sites.
D.)Actin produces myosin and ATP.

Which of the following would be a body response when stepping outside without a coat on a snowy day? a. senaceous glands. secrete more senum b. more liquid is transported by the body to the skin fir insulation c. blood vessels in the skin narrow and contract d. blood vessels in the skin expand

3differences between bacteria and other 2 cells

What does the number 18.9984 represent in the image?