Answer:
When the calcium level is high in the bloodstream, the thyroid gland releases calcitonin. Calcitonin slows down the activity of the osteoclasts found in bone. This decreases blood calcium levels. When calcium levels decrease, this stimulates the parathyroid gland to release parathyroid hormone.
The options for this question are:
- Requires genetic variation
- Results in descent with modification
- Involves differential reproductive success
- All of the above
Answer:
<u><em>The correct option is d) All of the above</em></u>
Explanation:
The theory of natural selection explains that genetic variations occur in organisms of a species. Those organisms which are better adapted to live in an environment are able to survive and pass on their characteristics to their offsprings, hence descent with modification. Through this phenomenon, evolution takes place with the passage of time. Natural selection favours survival of the fittest. Hence, all of the above statements are true.
Answer:
presence or absence of a protective covering over the ovule
Explanation:
In angiosperms, seeds develop from ovules and are enclosed in the ovary. So, their is the presence of protective covering making the seeds enclosed.
On the other hand, gymnosperms have seeds that are borne on cones, so they are naked due to the absence of any protective covering over the ovule.
Plants and animals could not live without nitrogen<span>. It is an </span>important<span> part of many cells and processes such as amino acids, proteins, and even our DNA. It is also needed to make chlorophyll in plants, which plants use in photosynthesis to make their food and energy. hope this helps!</span>
Answer:
Make reclamation mandatory after limestone has been removed
Explanation:
