Answer:
A. Nitrogen is the most abundant
.
B. Oxygen is the most plentiful gas about 21% by volume.
Explanation:
Nitrogen is the most abundant gas present in the atmosphere about 78 % by volume while the second most abundant gas is oxygen which is about 21 % in the atmosphere which is used by the living organism for breathing and energy production. Nitrogen is used by the plants for the production of amino acids and enzymes formation. Carbon-dioxide is present in a very low amount about 0.03 % in the atmosphere which is used by the plants during photosynthesis process.
The organism that you described is most likely a star fish. All its limbs go from the middle and if one is damaged or removed, a new one will grow from the center to replace it.
Answer:
Option A, hydrophilic/hydrophobic forces
Explanation:
The cytoplasmic membrane consists of phospholipids which have both the hydrophilic and hydrophobic regions and hence are amphipathic in nature. Due to this structural complexity, phospholipids produces barrier both at the interior and exterior of cell and hence form a membrane bilayer under suitable conditions. For instance when it is in water, it arrange itself in a way that their hydrophobic tails lie at the inner side and hydrophilic heads face outer side.
Hence, option A is correct
(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:
You need to know the conditions required for natural selection to occur. These include: overproduction of offspring, inherited variation, and the struggle to survive, which result in differential reproductive success. You need to understand genetic drift and gene flow
Explanation:
