Q.1 what is cell?
Ans. The word cell come from Latin word
“Cellula” which means small compartment. Cell is a basic unit of life, because
all the animals and plants are made of cells. Cells are like the bricks of a
wall. Cells are different in shape and size, they perform different functions.
Q.2 who discovered cell?
Ans. Cell was discovered and named by an
English scientist Robert Hooke in 1665. He viewed a piece of cork was made up
of thousands of tiny “boxes”. He called those boxes cells.
Q.3 what are unicellular organisms?
Ans. The organisms that are made up of only one
cell called unicellular organisms such as: bacteria, paramecium and amoeba.
Q.4 what are multicellular organisms?
Ans. The organisms that are made up of multiple
cells called multicellular organisms such as: human beings, cow, and donkey.
Q.5 Describe the main parts of cell?
Ans. Cell is consist of following main parts,
(i) Cell membrane (ii) Cytoplasm (iii) Nucleus
(iv) Mitochondria
(v) Chloroplast
Cell
membrane it is a thin layer with tiny holes that encloses the cell and
maintains the shape of a cell. It also protects cell from its surroundings.
Water, oxygen, carbon dioxide and food that enter or leave a cell have to pass
through cell membrane. It is also known as plasma membrane.
Cytoplasm It is a
jelly like substance which is filled with water. It holds the cell organelles
like cell’s nucleus and mitochondrion etc…
Nucleus It is
the main part of a cell. It controls all the chemical activities and life
processes of a cell. It contains DNA that instructs rest of the cell what to do.
It is also termed as the brain of a cell. It was discovered by Robert brown in
1831.
Mitochondria
It is the powerhouse of a cell because it makes energy for a cell.
Chloroplast
It founds only in plants cell. It contains green pigment chlorophyll. Plants
have green colour due to chlorophyll. It also helps them to make their food.
Q.6 what is tissue?
Ans. Tissue is a group of similar cells to
perform specific function.
Q.7 what is an organ?
Ans. It is group of different kinds of tissues,
organized to perform special function. As: heart, kidneys, brain are examples
of organs.
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