Are you looking for Cell Structure and Functions Extra Questions and Answers, if yes? then you the right place. Here we are providing Cell Structure and Functions Extra Questions and Answers Class 8 Science Chapter 8.
Cell Structure and Functions Extra Questions and Answers Science Chapter 8
Que. 1) Solve the following multiple choice questions-
1) Organisms whose body is made up of more than one cell are called……………
a.) Unicellular organism
b.) Multicellular organism
c.) No- cellular organism
d.) acellular organism
Ans. b.multicellular organism
2) In addition to the cell membrane, there is an outer thick layer in cells of plants ehich protects the cell from various environmental extremes is called as……………
a.) Cell membrane
b.) Plasma membrane
c.) Cell wall
d.) Cytoplasm
Ans. c. cell wall
3) Nucleus is separated from the cytoplasm by a membrane which is called as the………………
a.) plasma membrane
b.) cell wall
c.) nuclear membrane
d.) vacuole
Ans. c. nuclear membrane
4) The central dense round body present in the centre of the cell is called……………
a.) Nucleus
b.) Nucleolus
c.) Nuclear membrane
d.) Vacuoles
And. a. nucleus
5) is the jelly-like substance which is present between the nucleus and the cell membrane is known as ………..
a.) cytoplasm
b.) Nucloplasm
c.) Periplasm
d.) All of these
Ans. a. cytoplasm
Que. 2. Answer the following questions in short-
1) Define cell.
Ans. Cell is a basic structural and functional unit of life.
2) Who observed cells first time under the microscope?
Ans. Cell was firstly observed by Robert Hooke under the microscope.
3) How many cells are there in human body?
Ans. Humans have trillions of cells in their body.
4) Define unicellular organism?
Ans. the organisms whose body is made of a single cell are the unicellular organisms. Ex- Amoeba and Paramecium
5) What are chromosomes?
Ans. Chromosomes are the thread- like structure present in the nucleus of the cell.
6) Give the example of unicellular organisms?
Ans Amoeba and Paramecium are the examples of unicellular organisms.
7) Define issue.
Ans. tissue is a group of similar cells performing a common function.
8) what is gene?
Ans. Gene is a unit of inheritance in living organisms that transfer of characters from parents to offsprings.
Que. 3. Answer the following questions:
1) Comment on shape of cells?
Ans. the shape of cell is related to the function they perform. Generally, cells are round, spherical or elongated in shape. Some cells are long and pointed at both ends exhibiting spindle shape structure. Cells may be are long or branched like the nerve cell.
2) What are the basic components of cell?
Ans. The basic components of a cell are as follows:
- Cell membrane,
- cytoplasm and
- nucleus.
3) What is the function of cell wall?
Ans. cell wall is an additional membrane present above the cell membrane. It protects cell from variations in temperature, high wind speed, atmospheric moisture etc.
4) Name the cell organelles you know?
Ans. Mitochondria, golgi bodies, ribosomes, nucleus, cell membrane, etc. are various cell organelles present in a cell.
Que. 4. Explain the following:
1) What is the function of chromosomes?
Ans. Chromosomes are the thread- like structure present in the nucleus of the cell. Chromosomes carry the genes which helps in inheritance or transfer of characters from the parents to their offsprings.
2) Comment on protoplasm?
Ans. protoplasm is the entire content of a living cell. Hence, protoplasm is also called the living substance of the cell. It includes the cytoplasm of the cell and the nucleus.
3) Differentiate between prokaryotes and eukaryotes?
Ans.
Prokaryotes | Eukaryotes |
nucleus of the cell is not well-organised | nucleus of the cell is well organised |
nuclear membrane is absent | nuclear membrane is present |
Ex- bacteria, blue green algae | Ex- all cells except bacteria, blue green algae |
4) Differentiate between Plant Cell and Animal Cell with the help of following table?
Cell organelle | Plant Cell | Animal Cell |
Cell membrane | ||
Cell wall | ||
Nucleus | ||
Nuclear membrane | ||
Cytoplasm | ||
Plastids | ||
Vacuole |
Ans.
Cell organelle | Plant Cell | Animal Cell |
Cell membrane | Present | Present |
Cell wall | Present | Absent |
Nucleus | Present | Present |
Nuclear membrane | Present | Present |
Cytoplasm | Present | Present |
Plastids | Present | Absent |
Vacuole | Present. Usually large in size and less in number. | Present. Usually small in size and more in number |