hort Answer Questions :
1 Name the scientist who invented the first microscope
2. Who coined the term "cell" ?
3. Briefly describe the three essential parts of a cell.
4. The cell membrane is called selectively permeable. Why?
5. State the difference between :
(0) Nucleus and nucleolus.
(ii) Cytoplasm and protoplasm.
(iii) Cell wall and cell membrane.
6. List the major differences between a plant cell and an animal cell.
7. Briefly discuss the importance of chromosomes in an organism.
*. Fill up the blanks with the terms given below in the box.
Answers
Answer:
Zacharias Janssen
Robert Hook
the three essential parts of a cell are... 1. cell membrane 2. cytoplasm 3. nucleus
it regulates the movement of substance in and out of the cell. so the cell membrane is called selectively preamble membrane
6. plants cells are usually larger compared to animal cell. ........ animal cell don't have cell wall but plants cell have cell wall
Answer:
1. A Dutch father-son team named Hans and Zacharias Janssen invented the first microscope.
2. Robert Hooke
3. The essential basic parts of a cell are:
Cell membrane
Cytoplasm
Nucleus
Cell membrane — It is a very thin, delicate and flexible membrane which surrounds each cell. It is also called plasma membrane. It consists of fine pores which allow only certain molecules to pass through it and prohibit the others and therefore, due to its function, also called selectively permeable membrane.
Cytoplasm: This is the living portion of the cell which is a semi-liquid, translucent and colourless liquid. It is the portion of the cell where major functions of the cell are carried out through various finer parts of the cell. The finer structures which are contained in this are called the cell organelles.
Nucleus: The small spherical dark coloured body usually located in the centre of the cell. It is the most important part of the cell which regulates and co-ordinates various life processes. Its major role is during cell division. It contains hereditary factors called the genes.
4. Plasma membrane called a selectively permeable membrane because it regulates the movement of substances from within to outside of the cell. This means that the plasma membrane allows the entry of some substances while preventing the movement of some other substance.