Cell : The Unit Of Life Flashcards
What is a cell?
A cell is a fundamental structural and functional unit of all living beings. It is the smallest part of the body of an organism which is capable of independent existence and perform the essential functions of life.
With what is all living organisms made of?
The cell.
What happens to the old and weak cells?
Old and weak cells continually dies and are replaced by new cells.
What is the Life span of a Red Blood Cells?
120 days.
How did most organisms started their life?
Most organisms including human beings start their life as a single cell called a zygote.
Who constructed the first microscope? What did he do in his profession?
Antony Van Leeuwenhoek a Dutch scientist constructed the first microscope. In his profession, he grounded lenses and made microscopic observations as his hobby.
What was the name of the microscopes constructed by Antony van Leeuwenhoek and why? And what was their magnifying power?
The name of microscopes constructed by Antony van Leeuwenhoek was named simple microscopes because they all consisted of a single biconvex lens. Their magnifying power was up to 200 times.
How were the simple microscopes used?
In simple microscopes, the eye was kept close to the lens on one side and the object was mounted on the needle-like screw point on the opposite side of the lens.
Who made the first compound microscope and how?
Robert Hooke, an English scientist developed a microscope with two lenses achieving a greater magnification which came to be known as the compound microscope.
How was the compound microscope used?
The object to be seen was placed on the stage below and light from oil flame was thrown on it by means of a concave mirror.
