To provide energy to the body.
The correct answer is D. Bacteria and archaea
Explanation:
In biology, cells can be mainly classified into prokaryotic and eukaryotic. The prokaryotic cells are cells with no nucleus or centrioles but they do have a cell wall, usually one chromosome and complex cilia and flagella. On the other hand, prokaryotic cells have a defined nucleus, multiple chromosomes, and centrioles and some have a cell wall. Due to the differences between these two type of cells they are part of different organisms, in the case of eukaryotic cells, these are part of the complex organism that includes animals, plants, and fungi while prokaryotic cells are those found in bacteria and archaea which are organisms with only one cell. Considering this, the ones that consist of prokaryotic cells are bacteria and archaea.
Answer:
The correct answer would be Atria push blood into the ventricles and Ventricles push blood out of the heart.
In humans, four chambered heart is present with two atria and two ventricles.
Deoxygenated blood from all over the body is passed into the right atrium through vena cava (superior and inferior).
Simultaneously, oxygenated blood from the lungs is passed into the left atrium of the heart with the help of pulmonary vein.
Both the atria contract at the same time to drain their blood into respective ventricles.
The ventricles undergo relaxation while receiving blood.
The valves present between the atria and ventricles (tricuspid and bicuspid valve) ensures that the blood flows in one way direction only. They shut down as the ventricles contract and produce the sound "lub".
The ventricles contract simultaneously to pump blood out of the heart. The right ventricle pumps deoxygenated blood into pulmonary artery which takes the blood to the lungs for oxygenation.
The left ventricle passes the oxygenated blood through aorta to all the parts of the body.
The pulmonary and aortic valves prevent the back flow of blood and shut at the same time which creates second sound called as "dub".
One example can be the needle shaped leaves.
In desert areas, there are not much water sources. So basically, any drop of water is precious. To help prevent water loss of plants, for example cactus has very thin leaves that are needle shaped. Or some even don't have any leaves. This can reduce the surface area of leaves and thus reduce the water evaporating to the outer environment.
Another example also shown on cactus is that they have very thick waxy cuticle. It can also prevent water from evaporating from the stem. So that's why you see the stem is very shinny.
