Answer:
- A star’s final stages of life depend on its mass
- Stars die when they run out of fuel
Explanation:
Stars die differently when their core can no longer fuse atoms, depending on their solar masses. The very big stars are able to burn helium into carbon and some able to fuse even carbon. The big stars die to form neutron stars and supernovas. Stars of low solar masses die out by forming white dwarfs.
Answer: A virus lack the metabolic machinery common to other microorganisms
Explanation:
A virus is an ultramicroscopic particle capable of causing disease. It differs from other disease-causing organisms like bacteria, nematodes etc, because it has no metabolic system of its own but relies on its host system for survival and replication.
Hence, it is difficult for antibiotics to target and destroy viruses without harming patients, rather antiviral drug are prescribed against viruses
(1) The varying number of muscle fibers that contract
<span>In most muscles, the number of muscle fibers in different motor units ranges from a few to hundreds. The nervous system can thus regulate the strength of contraction in a muscle by determining how many motor units are activated at a given instant and by selecting large or small motor unties to activate. </span>
some muscles are almost always partially contracted. In such muscles, the nervous system my alternate activation among the motor units, reducing the length of time any one set of fibers is contracted. Prolonged contraction can result in muscle fatigue due to the depletion of ATP and dissipation of ion gradients required for normal electrical signals.ing.
<span>(2) varying the rate at which muscle fibers are stimulated </span>
<span>single action potential produces a twitch lasting about 100 msec or less. If a second action potential arrives before the muscle fiber has completely relaxed, the two twitches add together, resulting in greater tension. Further summation occurs as the rate of stimulation increases. When the rate is so high that the muscle fiber cannot relax at all between stimuli, the twitches fuse into one smooth, sustained contraction called tetanus.</span>
Answer:
Yes it can, the one parents genes can be stronger than the other
Answer:
4. The cell has chloroplasts to turn sunlight into food
