How long ago do we think cells with nuclei developed on earth?

The skeletal system performs a variety of functions that are crucial to maintaining life processes. what function is performed in the bone marrow, but not in the ossified bones of the skeleton? a oxygen transportation c mineral storage b. muscle attachment d red blood cell production

92 sathe best for the question 11. most animals and plants reproduce sexually. this means that dna is passed down to new organisms from two parental organisms. which of the following is a key advantage of sexual reproduction?

What evidence supports the law of conservation of energy? a) mechanical energy is converted to chemical energy during photosynthesis. b) oxygen is made from the breakdown of carbon dioxide during photosynthesis. c)energy is absorbed by chlorophyll and becomes chemical energy during photosynthesis. d)the sun gives off light energy that is absorbed by plants.