Living Beings and Their Structure Class 8

 

Living Beings and Their Structure

Multiple Choice questions:

1.       What is called for the science that deals with the study of cells?

a) cytology            b) histology          

c) Biology              d) Physiology

2.       Which of the cell organells is not found in animal cell?

a) mitochondria   b) plastid  

c) ribosome           c) nucleus

3.       Which of the following is not the basis of two kingdom system of classification?

a) nutrition            b) locomotion      

c) evolution           d) reproduction process

4.       Which organism belongs to the kingdom mycota?

a) yeast                  b) chlamydomonas            

c) verticella           d) chorella

5.       What is called for the preserving food by keeping them in very low temperature?

a) dry preservation              b) cold preservation           

c) wet preservation              d) food preservation

6.       What is the kingdom of blue green algae?

a) Monera             b) Protista             

c) Fungi                  d) plantae

7.       Who is the propounder of binomial system of nomenclature?

a) Carolous Linnaeus         b) Robert H. Whittaker

c) Chatton                             d) Robert Koch

8.       Which of the following is an example of prokaryotic microorganism?

a) Azobacter         b) Euglena            

c) Yeast                 d) Amoeba                           

9.       Which scientist propounded five kingdom system of classification?

a) Carolous Linnaeus         b) Robert H. Whittaker

c) Gregor Mendel                 d) Robert Koch

10.    Which of the following kingdom of organism does not contain definite nucleus?

a) Monera                             b) Protista             

c) Fungi                                  d) plantae

11.    What is the reason mushroom called saprotrophic organism?

a) It  cannot prepare its food by itself

b) It can obtain food from dead and decaying matter.

c) It depends on other for its food.

d) It sucks the food from other organisms.

12.    What is indicated by R in the given figure?

a) Nucleus             b) Chloroplast     

c) Mitochondria   d) Vacuole

13.    a

Answers: 1(a), 2(b), 3(c), 4(a), 5(b), 6(a), 7(a), 8(a), 9(b), 10(a), 11(b), 12(d)

Group B (very Short Answer Questions)

1.       What is the kingdom of mucor?

The kingdom of monera is Fungi.

2.       What is cytoplasm?

Cytoplasm is a jelly like fluid present between the nucleus and cell membrane.

3.       Write the names of any two cell organelles found in cytoplasm.

The names of two cell organelles found in cytoplasm are mitochondria and golgi bodies.

4.       Who discovered the cell and when?

Robert Hooke discovered cell in 1665 AD.

5.       Why is cell regarded as the basic unit of life?

Cell is regarded as the basic unit of life because it is the smallest unit of all living organism which is capable to perform all the function required for a living being.

6.       What is chlorophyll?

Chlorophyll is a green coloured pigment which makes the plants green and help the plants to prepare their own food.

7.       Why is virus called obligatory parasite?

Virus is called an obligatory parasite because it shows the characteristics of living being only inside the living cell and is found in crystalline form outside the living cell.

8.       What is fermentation?

Fermentation is the metabolic process of conversion of carbohydrates into alcohol and organic acids by some fungi and bacteria.

9.       Give an example of wet preservation.

Pickles kept in oil or vinegar is an example of wet preservation.

10.    Write the name of bacteria that convert milk into yoghurt.

The name of the bacteria that converts milk into yogurt is lactobacillus.

Group C (Short Answer Question) 2 marks each

1.       Write any two features of five kingdom system of classification.

Two features of five kingdom system of classification are:

a.       Prokaryotes and eukaryotes are separated.

b.       Unicellular and multicellular organisms are separated.

2.       What is cell? Why is it called the basic structural and functional unit of living beings?

A cell is the structural and functional unit of life. Cell is regarded as the basic unit of life because it is the smallest unit of all living organism which is capable to perform all the function required for a living being.

3.       Draw a well-level diagram of an animal cell.

1.        Show two major differences between food vacuole and contractile vacuole.

The major differences between food vacuole and contractile vacuole are:

Food Vacuole	Contractile Vacuole
1. It stores and digests the food.	It maintains the water balance in the cell.
2. It is found in both the unicellular and multicellular organisms.	It is found in unicellular organisms.

 5.       Draw a well labeled diagram of plant cell.

6.       How do amoeba and hydra reproduce? Describe in brief.

Amoeba reproduces by binary or multiple fission and hydra reproduces by budding.

Binary fission and multiple in amoeba: In binary fission, a single mother cell divides into two daughter cells while in multiple fission, a single cell produces large no of minute cell.

Budding in hydra: A small outgrowth develops in the body of hydra called bud. This bud gradually grows and after being matured, it detaches from its parent boy and survive as a new individual.

7.       What is cell wall? Write its function.

A cell wall is the outermost tough covering of a plant cell. Its functions are:

a.       It protects the cell from external injury.

b.       It helps in transporting substances in and out of the cell.

8.       Show two differences between plant cell and animal cell.

Two differences between plant cell and animal cell are:

plant cell	Animal cell
1. The outermost covering of the cell is cell wall.	The output covering of the cell is cell membrane.
2. It helps plastids.	It does not have plastid.

9.       Sketch a labeled diagram of amoeba.

10.    Write any two differences between prokaryotic cell and eukaryotic cell.

Two differences between prokaryotic and eukaryotic cell are:

Prokaryotic cell	Eukaryotic cell
1. They not have any definite nucleus.	They have a definite double membrane bonded nucleus.
2. They are mostly unicellular.	They are both unicellular and multi cellular.

11.    Five kingdom system of classification is more appropriate and scientific than two system of classification. Give reason.

Five Kingdom system of classification is more appropriate and scientific than two system of classification because of the following reasons:

a.       Five Kingdom system of classification has clearly classified microorganisms prokaryotes, eukaryotes and fungi but in two system of classification, all these organisms are only kept into plante or animalia.

b.       Unicellular and multicellular organisms are separated in Five kingdom system of classification but separation is not found in two system of classification.

12.    Write any two drawbacks of two kingdom system of classification.

The drawbacks of two Kingdom system of classification are:

a.       Autotrophic and heterotrophic are kept together.

b.       It does not separate unicellular and multicellular organizations.

13.    Write down one advantage and disadvantage of bacteria.

Advantage of bacteria: They are used to produce antibiotics.

Disadvantage of bacteria: Pathogenic bacteria may cause different kinds of diseases to plants, animals and human being.

14.    Draw a figure of virus and label any 2 parts of it.

15.    How is amoeba being used by mankind for beneficiary purposes? Explain.

Amoeba cannot be used directly by mankind for beneficiary but it can be used through the ecological and research method.

a.       Amenable are the decomposers, which survive on dead and decayed bodies for their food. Thus, they can be used to maintain a balance of nutrients in the nature.

b.       Amoeba can also be used for the research in  medical sector as well as in understanding the cellular biology.

16.    Why is virus called both living as well as non living?

Inside the body of living host cell, virus behaved like a living parasite. They are inactive and like a dust particle outside the living cell. Therefore virus is called both living as well as non living.

17.    What is the full form of DNA and RNA?

The full form of DNA is Deoxyribonucleic Acid and RNA is Ribonucleic Acid.

18.    What do you mean by unicellular animals? Give any two examples.

The animals which possess a single cell can complete all their life activities within the single cell are called unicellular animals. For example amoeba, euglena, etc.

19.    Write any two main functions of nucleus.

Two functions of nucleus are:

a.       It controls the metabolic activities in the cell.

b.       It helped in cell division which is necessary for the growth and development of a body.

20.    Write any two differences between Differences between cytoplasm and nucleoplasm.

Two differences between cytoplasm and nucleoplasm are:

Cytoplasm	Nucleoplasm
1. It is a feud like substance present between the nucleus and the plasma membrane.	It is a transparent semi fluid substance inside the nuclear membrane.
2. Cell organelles are found freely floating on cytoplasm.	Nucleolus chromatin network and enzymes are found in the nucleoplasm.

 

21.    Write any two differences between chloroplast and chromoplast.

Two differences between chloroplast and chromoplast are:

Chloroplast	Chromoplast
1. It contains chlorophyll.	It contains color pigments.
2. They are the site for photosynthesis.	They give calories to the fruits and flowers.

22.    Write any two differences between cell wall and cell membrane.

Two differences between cell wall and cell membrane are:

Cell wall	Cell membrane
1. Cell wall is present only in plant cell.	Cell membrane is present in both the plant cell and animal cell.
2. It is made up of cellulose.	Cell membrane is made up lipid and protein.

23.    Write any two differences between cell organelles and cell inclusion.

Cell organelles	Cell inclusion
1. Sell organelles are living structure of the plant and animal cell.	Cell inclusions are the nonliving components of the plant and animal cells.
2. Cell organelles carry out metabolic activities.	Cell inclusions are the substances required for metabolic activities.

24.    Ribosomes are also called protein factories. Why?

Ribosomes help in the production of non-essential proteins. So they are also called protein factories.

25.    Cell wall provides a fixed shape to the plant cell. Why?

Cell valve contains cellulose which is rigid and strong to tolerate pressure. So it provide fixed shape to plant cell.

26.    Metabolism occurs in cytoplasm. Why?

Metabolism occurs in the cytoplasm because the cytoplasm is a cellular compartment that contains various organelles and structures necessary for essential metabolic processes.

27.    Cell is considered as the basic unit of life, why?

See QN. 5 of Very short Question and QN 2 of Short Questions.

28.    Write the names of any two cell organelles found in cytoplasm and their functions.

Two cell organelles found in cytoplasm and their functions are:

Vacuole: It stores water, sugar salt and waste material of the cell.

Ribosome: It synthesizes protein.

29.    Write any two differences between two kingdoms system of classification and five kingdom system of classification.

Two differences between two kingdom system of classification and five Kingdom system of classification are:

Two kingdom system of classification	Five Kingdom system of classification
1. Eukaryotes and prokaryotes are included within the same kingdom.	Eukaryotes and prokaryotes are separated.
2. Plants and fungus are kept together.	Plants and fungus are separated in different kingdoms.

 

30.    Virus is called a very small infectious particle but not an organism, why?

Virus is called a very small infectious particle but not an organism because it appear like a crystal outside the living cell and does not show any characteristics of living organism. It causes infection to the living organism when entered into their body.

31.    We should not consume stale and smelly food, why?

Stale and smelly food contain microorganism such as Bacteria and fungus. These microorganisms cause different kinds of diseases such as diarrhea, dysentery food poisoning, abdominal pain, etcetera.

32.    Foods do not get spoiled if preserved after drying well. Why?

Bacteria and fungus grow on moist materials. Drying of food removes the moisture present in food. So, microorganisms cannot grow on dry food and hence the food is preserved from being spoiled when dried.

33.    Which cell organelles of cell undergo self digestion and why?

Lysosomes of cell undergoes self digestion because they contain digestive enzyme hydrolase which enter the cell by breaking the membrane of lysosom and digest the worn out cell organelles, food particles, bacteria and virus and finally destroy the cell.

34.    Make a list of cell organelles and cell inclusion found in a cell.

List of cell organelles and cell inclusion found in a cell are:

Cell Organelles	Cell inclusion
1.       Plasma membrane	Glycogene
2.       Cytoplasm	Lipids
3.       Nucleus	Protein or amino acids
4.       Golgi apparatus	Melanin
5.       Endoplasmic reticulum	gases
6.       Ribosome	enzymes
7.       Lysosome	hormones
8.       Vacuole
9.       Cilia and flagella
10.    Cytoskeleton
11.    plastids
12.    Centriole and Centrosome

35.    Complete the adjoining Venn diagram by comparing animal and plant cells.

36.    Mention the role of Golgi body and vacuole in a cell.

The function (role) of Gulgi body and vacuole in a cell are mentioned below :

Role of Golgi body	Role of Vacuole
1. It stores, packages and distributes the protein and lipids.	It stores water, sugar, salt and other waste materials.
2. It manufacture substances like cellulose and pectin.	It maintain turgid pressure and hence maintain the shape of cell.

 

37.    Among various organelles of a cell, which one is the most important in your opinion and why?

Among the various cell organelles of a cell nucleus is the most important in my opinion. It is because of the following reasons:

a.       It is the brain of a cell and controls all the metabolic activities.

b.       It contains genetic material in it which is nursery for reproduction, growth and development of an organism.

38.    What would happen in plant life process if there were no chloroplasts in them? Present your opinion.

If there were no chloroplasts in plants, all the plants will be heterotrophic and they depend on external energy sources for their food. The results in scarcity of food for all other organisms and thus it bring global decline in oxygen which ultimately lead to the destruction of life on the Earth.

39.    What is the reason that the nucleus is also called the 'brain of cell'? Clarify.

Nucleus control all the activities including metabolic activities of the cell. It controlled the functioning of the cell and hence it is called the 'brain of the cell'.

40.    If there were no metabolic processes in a cell, what effect would occur in the live processes of organisms? Explain on the basis of relationship between cell tissues and organs.

Cell is called the fundamental unit of life. There are no other smaller units than the cell that can perform all the functions such as digestion respiration ingestion metabolism etcetera. If there were no metabolic process in a cell, there will not be any production of energy, digital of food, respiration, transportation, etc. Thus, the functioning of whole tissues and organs will be ceased in organisms. 

41.    What is classification? How does classification make the study of organisms easier?

The act of grouping of organisms on the basis of their similar and dissimilar properties is called classification. Classification makes the study of organisms easier in the following ways:

a.       It helps to learn about the characteristics of large number of plants and animals in a group.

b.       It is a systematic and scientific study so it is easier to understand  and study the cells.

42.    Show any two differences between virus and bacteria.

Two differences between virus and bacteria are:

1. Vitas do not have any cellular organization.	1. Bacteria have cellular organization.
2. They do not show any life activities outside the living cell.	2. They can show the living activities both in the cells and outside the cell.

43.     

Group D (Long Answer type Questions) 4 marks each

1.       Write one function of each of endoplasmic reticulum, ribosomes, Golgi bodies and lysosome.

One function of each endoplasmic reticulum, ribosome, Golgi bodies and lysosome are as follows:

a.       Endoplasmic reticulum: It transports the molecules to specific destination.

b.       Ribosome: It synthesizes the protein.

c.        Golgi bodies: They store package and distribute protein and lipids made in the endoplasmic reticulum.

d.       Lysosomes: They engulfed virus on bacteria and protect the cell organisms from foreign bodies. 

2.       What is chromosome? Where it is found? Write its two functions.

Chromosomes are the thread like structures which help in transmission of genetic character from parents to the offspring. Chromosome is found in the nucleus of a cell. Its two functions are as follows:

a.       Chromosomes contain DNA which help in transmission of parental characteristics to the offspring.

b.       They help in cell division. 

3.       Define unicellular and multicellular animals with two examples of each.

The animals which are made up of single cell are called unicellular animals. For example bacteria, euglena, amoeba, etc.

The animals which are made up of large number of cells are called multi cellular organisms. Examples of multicellular organisms are human being, birds, reptiles etc.

4.       Write one function of each of the given below.

a) Pseudopodia b) cytoplasm c) centrosome d)cell membrane

The function of each are given below:

a.       Pseudopodia: They help in locomotion in amoeba.

b.       Cytoplasm: It maintains the turgidity of the cell.

c.        Centrosome: It helps in the formation of a spindle fiber during cell division.

d.       Cell membrane: It acts as a protective covering of a cell.

5.       What is plastid? Write its type and one function of each of them.

Plastids are the disk shaped double layered cell organelle found only in plant cell, few bacteria and euglena. Plastids are of three types. They are chloroplast chromoplast and leucoplast.  One function of each of the plastids is mentioned below:

a.       Chloroplast: chloroplast help in trapping the sunlight for photosynthesis.

b.       Chromoplast: It helps in ripening of fruits and gives coloration to the flowers.

c.        Leucoplast: leucoplast is involved in synthesis of starch oils and protein.

6.       Write the cell organelles found only in plant cell and only in animal cells.

The cell organelles only found in plant cell are: cell wall, chloroplast, chromoplast, leucoplast and vacuole. The cell organelles which are only found in animal cell are: centrosome, centriole, lysosome, flagella and cilia, 

7.       Write two functions of each of vacuole and nucleus.

Two functions of each of the nucleus and vacuole are given below:

Functions of Vacuole:

a.       Vacuole stores water sugar salt and other waste material of the cell.

b.       The space inside the vacuole helped to maintain the turgidity of the cell.

Functions of Nucleus:

a.       Nucleus controls the metabolic activities in the cell.

b.       It helps in the cell division which is necessary for the growth and development of living organisms.

8.       Write any four basis of 5 Kingdom system of classification.

Four bases of five kingdoms system of classification are mentioned below:

a.       Complexity of the cell structure on the basis of prokaryote and eukaryote.

b.       Number of cells that is unicellular or multicellular.

c.        Mood of nutrition (autotrophic or heterotrophic).

d.       Tissue level organizations.

9.       Five kingdom system of classification is more appropriate and scientific than two kingdom system of classification. Justify this statement with any four bases.

The following basis supports that the five system of classification is appropriate and scientific than two kingdom system of classification:

a.       In five system of Kingdom of classification organisms are separated into eukaryotes and prokaryotes. Such custom of classification is not found in 2 kingdoms system.

b.       Unicellular and multicellular organisms are separated.

c.        Green plants and non green plants like algae and fungi are kept in separate groups.

d.       Five kingdom system of classification is also related with the evolution of organisms.

10.    Clarify the relationship between cell tissues and organs in a human body.

11.    Cells are the smallest structural and functional unit of the Human body. When a group of specialized cells perform a single job they form a tissue. When a group of tissues carry out a particular function in the body they form the organ and when a group of organs perform the life process in the human body it constitute an organ system. The combination of organ system constitute human body.

12.    How can you observe onion cell under a microscope? Explain in brief.

We can absorb onion cell under a microscope by the following activities:

a.       An onion is taken and its outer dry scales are removed.

b.       It is cut into small section from its fleshy layer.

c.        A thin transparent layer is peeled out carefully with the forceps.

d.       It is placed on a watch glass containing water.

e.        The slice of thin layer is then transferred into the glass slide.

f.        A few drops of saffron is added for coloration and it is washed with distilled water.

g.        The slide is observed under the microscope.

13.    Draw a well-labeled diagram of a plant cell and an animal cell.

See QN 3 and QN 5 of Group C

14.    What are the methods of food preservation? Describe any one method and mention the importance of food preservation.

The methods of food preservation are dry preservation, cold preservation and wet preservation. Besides this freezing, salting, sweetening, boiling and canning are also used.

15.    What is food poisoning? Mention its causes and the measures to be safe from it.

Food poisoning, a type of food borne illness, get from something we ate or drank. The causes are germs like bacteria, fungus, amoeba or other harmful things in the food or beverage.

Measures to be safe from food poisoning are:

a.       We should not consume stale food, spoiled food or any food from the floor.

b.       Hands should be washed with soap and water before and after eating food.

c.        Proper sanitation rules should be followed.

d.       Foods should not be kept uncovered.

16.    Make a list of any four diseases caused by microorganisms.

Dysentery, diarrohea, malaria, ringworm, tuberculosis, common cold, chicken pox etc. are the names of some diseases caused by microorganisms.

17.    Write any four advantages of microorganisms.

Four advantages of microorganisms are:

a.       Microorganisms are used to make medicines like penicillin.

b.       They are used in the manufacture of alcoholic beverages, leather, cheese, yoghurt, etc.

c.        They maintain the concentration of various nutrients in the soil by decomposing dead and decayed matter.

d.       They help in digestion of food in human being and other animals.

18.    Mention the two merits and two drawbacks of two Kingdom system.

Two merits of two kingdom system of classification are:

a.       It is simple clear and easy to understand.

b.       It is the first scientific method of classification of organisms.

19.    Two drawbacks of true kingdom system of classification are:

a.       Plants and fungi are kept together.

b.       Unicellular and multi cellular organisms are not separated.

20.    Mention the bases and features of Five kingdom system.

The bases and the features of five kingdoms system of classification are as follows:

Bases

a.       The complexity of the cell (prokaryotes and eukaryotes)

b.       The complexity of the organism's body (unicellular and multi cellular).

c.        The mode of nutrition (autotrophic or heterographic).

21.    Features:

a.       Prokaryotes and eukaryotes are kept in separate kingdom.

b.       Unicellular and multicellular organisms are separated.

c.        Green plants and non-grain plants like algae and fungi are kept in separate groups.

22.    Two kingdoms system has not differentiated prokaryotes and eukaryotes, how is this corrected by 5 kingdom system? Describe in brief.

Two kingdom system of classification has not differentiated prokaryotes and eukaryotes however, it has been corrected in five system of classification. In five kingdom system of classification all the prokaryotes which are simple in structure are kept in the kingdom Monera while all the uni cellular you carried are kept in kingdom Protista.

23.    Fungus sometimes grew in pickles made in home and kept in a bottle or jar. Why does it happen? What should be done to protect pickles from fungal attack? Write any two ways.

Fungus sometimes grows in the pickles made in home and kept in bottle due to improper sterilization, lack of air tight lid or lack of better preservatives.

The pickles can be protected from fungal attack by adapting following methods:

a. Use plenty of oils to prepare the pickles. Keep a layer of oil on the top of the pickle.

b. Keep the pickles in glass jar. Avoid plastic containers.

c. The glass jars must be thoroughly washed and dried in sunlight.

d. Use dry spoon to take pickles.