The correct answer is - D. A drought kills all the plants in an area, leaving bare land.
If there's such a big drought that will manage to kill off all the vegetation in an area and leave bare land behind it, than the land will be degraded in no time. Once the land is left without its natural protection that the roots of the vegetation provide, the land will be exposed to high rates of and erosion. The erosion will be very quick and the top layers of the soil will be moved away with every wind and rainfall that will appear. That will degrade the land to a very high degree, making it totally unusable and it will need lot of time to eventually recuperate.
<h2><u>
Heart and lungs:</u></h2>
The upper chamber of the heart is called atrium and lower chamber of the heart is called ventricles.
The blood circulation in the heart is basically under the functioning of three blood vessels namely:
<h3><u>Arteries:
</u></h3>
- They start with the aorta, the huge vein leaving the heart.
- Veins divert oxygen-rich blood from the heart to the majority of the body's tissues.
- They branch a few times, decreasing and littler as they convey blood more remote from the heart.
<h3><u>Capillaries:
</u></h3>
- These are little; flimsy blood vessels that associate the arteries and the veins.
- Their dainty dividers permit oxygen, supplements, carbon dioxide, and other waste items to go to and from our organ's cells.
<h3><u>Veins:
</u></h3>
- These are the blood vessels that return blood to the heart; this blood needs (oxygen-poor) and is wealthy in waste items that are to be discharged or expelled from the body.
- Veins become bigger and bigger as they draw nearer to the heart.
- The unrivaled vena cava is the huge vein that brings blood from the head and arms to the heart, and the second rate vena cava brings blood from the mid-region and legs into the heart.
Active muscles demand huge amounts of oxygen, and the circulatory system works hard to provide it. Blood carries oxygen to the muscles. When the body is at rest, blood carries nutrients to the muscles so that they can repair and rebuild themselves. Blood also carries away the waste products that hard-working muscles produce, back out through the lungs to be filtered.
so they Circulatory system xx muscular system :)
D) the nucleotide sequence in its DNA
