Answer:
A. Calcium would be transported to the sarcoplasmic reticulum therefore contractions would cease.
Explanation:
A muscle fibre will stop contraction immediately ATP is used up. Also, muscle contraction will end as soon as the information from the motor neuron stops. This repolarizes the sarcolemma and T-tubules, thereby closing the voltage-gated calcium channels in the sarcoplasmic reticulum. Calcium ions are then pumped back into the sarcoplasmic reticulum, in order for tropomyosin to cover the binding sites on the actin strands again.
Answer:
The humans use this limb to grab things, body language, and sign language.
The dogs use this limb for all kinds of weight-bearing activities like walking, jumping, running et cetera.
Birds use this to fly and whales use it as flapper.
The limbs of all these four animals are the example of homologous organs that is, they all are similar in structure but adapted to perform different functions during the course of evolution.
For example, in all four organisms, the limb is made up of the same set of bones such as humerus, radius, ulna, carpals, metacarpals, and phalanges.
Homology in structure shows that they must have evolved from a common ancestor and diverge to perform different functions as an adaptation to the contrasting environment.
Answer:
Photoperiod signifies towards the time that an animal or a plant gets exposed to light in a twenty-four-hour duration. Different types of plants need different durations of light exposure to follow their respective life cycles.
On the basis of getting exposed to light differently, the plants are differentiated into short-day plants, long-day plants, day-neutral plants, and intermediate-day plants. The day-neutral plants will undergo flowering at any length of the day, given that there is the availability of minimum amount of light, which is essential for usual growth. For example, beans, tropical plants, cotton, and others.
On the other hand, the intermediate-day plants will not flower if the days are too long or too short, like different varieties of grasses.
<span>Higher amounts of nitrogenous compounds will increase algal blooms, leading to less available oxygen in the water, and decrease biodiversity.
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Let's take a look at each option and consider them in light of our knowledge.
1. These compounds will combine into larger molecules as they interact in the nitrogen cycle and become food for fish and other animals, increasing biodiversity.
* This has some problems. Yes, the fertilizers will cause an increase in the food supply, but that doesn't spontaneously cause an increase in biodiversity. The only way to increase the biodiversity is to introduce new organisms. And this isn't such a mechanism. I won't pick this choice.
2. The water cycle will remove excess fertilizer naturally through evaporation, with no impact on biodiversity.
* There's some issues here as well. Think about how much fertilizer runoff is considered a pollution issue. If this option were true, then we wouldn't be seeing so many news articles complaining about fertilizer running causing pollution problems. So this answer isn't any good either.
3. Nitrogenous compounds will be recycled into carbon compounds to create new organisms and increase biodiversity.
* Still running into the "spontaneous increase in biodiversity" issue here. How would more carbon compounds suddenly increase the biodiversity? This answer isn't any good either.
4. Higher amounts of nitrogenous compounds will increase algal blooms, leading to less available oxygen in the water, and decrease biodiversity.
* This is a real problem. Some might think that "Algae is a plant. Plants produce oxygen. Why would more algae cause the oxygen supply to decrease?" Well, the answer is pretty simple. Individual algae cells don't live very long. So you have a log of algae being produced. Releasing oxygen to the air, and then dying. And the dead algae then proceeds to decay, which does consume dissolved oxygen in the water. Which does cause the death of fish and other animals that are dependent upon that dissolved oxygen. And that does reduce the biodiversity in the area. So this is a reasonable and correct answer.</span>
