What is the shortening of a muscle cell called?

1.contraction
2.expansion
3.piling
4.none of the above

Which statements about a food chain are true? choose all answers that are correct. a.plants are the first living organisms in food chains on land. b. the plants in a food chain are called herbivores. c. all food chains on land begin with energy from the sun. d. carnivores in a food chain eat only plants.