Fill in the blanks.

1. A _______________ is a device used to see very small objects such as cells.
2. A cell is the basic _______________ and_______________ unit of life.
3. Robert Hooke observed _______________ cells under a microscope.
4. Cells show diversity in _______________, _______________ and _______________.
5. One _______________ is one-thousandth of a millimetre.

The cells in a potato tuber do not have chloroplasts. How can you then identify them as plant cells by observing them under a microscope?

Write true or false. Correct the false statements.

1. A cell wall is found in animal cells.
2. Mitochondria are the carriers of heredity.
3. Nucleus is surrounded by a double membrane  called nuclear membrane.
4. Every species is characterized by a fixed number of chromosomes.
5. Centrosome is called the control centre of a cell.
6. Lysosomes are also called the powerhouses of a cell.

Tick the most appropriate answer.

1. The term cell was coined by 
   1. Matthias Jakob Schleiden.
   2. Robert Hooke.
   3. Theodor Schwann.
   4. Rudolf Carl Virchow.
2. The cell wall is made up of 
   1. proteins.
   2. fats.
   3. cellulose.
   4. vitamins.
3. Which of the following holds hereditary characters in an organism?
   1. nucleus
   2. chloroplast
   3. mitochondrion
   4. ribosome
4. Which of the following helps in cell division?
   1. centrosome
   2. ribosome
   3. plasma membrane
   4. lysosome
5. In a cell, proteins are formed with the help of
   1. nucleus.
   2. Golgi bodies.
   3. mitochondria.
   4. ribosomes.
6. The foldings of the inner membrane of a mitochondrian are called
   1. matrix.
   2. cisternae.
   3. cristae.
   4. vesicles.
7. Which of the following is called the powerhouse of the cell?
   1. chloroplast
   2. mitochondrion.
   3. centrosome
   4. sell wall
8. Which of the following organelles is called the 'suicide bag' of the cell?
   1. nucleus
   2. tonoplast
   3. ribosome
   4. lysosome
9. The green pigment is present in
   1. chromoplasts.
   2. amyloplasts.
   3. chloroplasts.
   4. leucoplasts.
10. The membrane surrounding the vacuole is called
    1. plasma membrane.
    2. nuclear membrane.
    3. tonoplast.
    4. cell wall.

Match the columns.