<span>it's colder the higher you go, a big body can retain heat better</span>
The answer is; E
This shows that these organelles were once free-living organisms with their own mechanisms for reproduction which they have retained even after years of symbiotic relationship with the higher organisms. During their duplication, they also replicate their own DNA. Their DNA does not have histones (as opposed to the DNA in the nucleus of their host eukaryotic cell) similar to that of simple organisms such as bacteria.
Answer:
The correct answer is myofibrils
Explanation:
The fundamental part of the muscle cytoskeleton is made up of myofibrils that are the contractile elements of skeletal muscle cells.Muscle fibers are made up of myofibrils, membranes, and cytoskeletal networks that anchor contractile fibrils to the sarcolemma. Myofibrils are composed of repeating contractile units known as sarcomeres and are perhaps the most ordered macromolecular structures in eukaryotic cells. Myofibrils are made up of actin and myosin filaments that are large polymerized protein molecules responsible for actual muscle contraction.
White blood cells produce antibodies which fight off the pathogens
