Answer:
a) virtual and erect
Plane mirrors are the only type of mirror for which a real object always produces an image
Arteries are blood carrying vessels which have thick, elastic, muscular walls, have no valves and in which blood flows under high pressure. The make up of arteries is unique to their function of transporting blood under high pressure.
All arteries carry oxygenated blood from the heart to all other parts of the body, with the exception of the pulmonary artery which carries de-oxygenated blood from the heart to the lungs. It is the only artery that transports blood which has not been oxygenated.
The molecules in the sugar move from an area of higher concentration (sugar cube) to an area of lower concentration in the water.
That is exactly what diffusion is: the net movement of molecules or atoms driven by a gradient , which means that it doesn’t requires energy.
Answer:
Due to presence at early days of the planet.
Explanation:
We only find the remains of single celled organisms in the oldest fossils because the single celled organisms are the organisms that were present in the early days of this planet. These single celled microbes were present about 3.7 billion years ago while on the other hand, the oldest rocks are only a little older i. e. 3.8 billion years so these single celled organisms are considered as oldest fossils on this planet.
