Carcinomas <span>are </span>cancers<span> that line the entire surface of the body as well as the internal structures and cavities.</span>
bacteria dont need to mutate, thats why they evolve. bacteria doesnt need to develop resistance. this can also make bacteria very dangerous though, virus's can evolve and change after a cure is created that cannot be affected by treatment.
The genotype of heterozygous would be PpLl.
Formed gametes are PP Pl pL pl
Parents: PpLl x PpLl
<span>The correct answer is
B. 9:3:3:1 ratio (9 polka-dot tails and long eyelashes, 3 polka-dot tails and short eyelashes, 3 solid tails and long eyelashes, 1 solid tail and short eyelash)</span>
Polka-dot tails and long eyelashes: PPLL PPLl PpLL PpLl PPLl PpLl PpLL PpLl PpLl
<span>Polka-dot tails and short eyelashes: PPll Ppll Ppll</span>
<span>Solid tails and long eyelashes: ppLL ppLl pp Ll</span>
<span>Solid tail and short eyelash: ppll</span>
Answer:
The correct answer is: D) the pivoting of the myosin head, which causes actin and myosin to slide relative to each other.
Explanation:
<u>Muscle contraction</u><u> occurs when the sarcomere is shortened.</u> The sarcomere is a structure composed of filaments: the thick ones are composed of myosin, and the thin ones are composed of actin. These two proteins interact with one another to make the sarcomere shorten and produce the contraction of the muscle.
Muscle, in its natural state, is not contracted. This is because <u>the binding sites on actin for the myosin heads are covered</u> by the proteins troponin and tropomyosin.
When the signal for muscle contraction arrives at the muscle, calcium ions are released from the sarcoplasmic reticulum and reach the sarcomere to reconfigure the complex formed by troponin and tropomyosin so <u>the binding site on the actin filament becomes exposed and the myosin head can attach to it.</u>
When an ATP molecule appears and binds to the myosin head, the latter separates from the actin-binding site and moves toward the next actin-binding site with the energy provided by the hydrolysis of this ATP molecule. This is what is called power stroke.
This keeps on happening until muscle contraction is no longer needed and calcium ions are reabsorbed, which will make troponin and tropomyosin cover the actin-binding sites once again.
The four principles of natural selection are variation (organisms within a population have their own individual differences in their appearance, such as, markings and color), inheritance (traits passed down to the offspring), high rate of population growth (which leads to their local resources to be more of a challenge to find), and differential survival/ reproduction (organisms in the population with stronger traits are more likely to survive and reproduce, aka survival of the fittest). These four principles work together to respond to chance in the environment by making sure the strongest survive and over time that species will adapt to their environment because the organisms with the better suited traits will pass their traits to its offspring.
I hope that made sense, lol.