Marco has experienced extreme fatigue (tiredness) lately. He eats three balanced meals each day and exercises 2-3 times per week on his Peloton bike. He gets 7-8 hours of sleep each night, but just can’t seem to stay awake during the day. Which organelle is most likely causing Marco’s problems?

6. in the dna double helix, how are the two strands of dna held together? a. chemical bonds between base pairs hold the two strands of dna together. b. hydrogen bonds between the base pairs hold the two strands of dna together. c. hydrogen bonds between sugar groups and phosphate groups hold the two strands of dna together. d. chemical bonds between sugar groups and phosphate groups hold the two strands of dna together.

Some birds look for food near cattle and other livestock. the movement of the cattle churns up the ground, making insects available to the birds. the cattle appear to be unaffected by the presence of the birds. what kind of relationship exists between the birds and the cattle? o a. parasitism o b. commensalism o c. predation o d. mutualism

Which environmental change would most likely result in bullfrog offspring that are able to store more water than bullfrogs in previous generations?