8th Standard Syllabus & Materials
8th Standard
TN 8th Tamil இயல் 3 - கல்வி கரையில - வினைமுற்று Important Questions And Answers Study Material - QB365 Set A
NEW8th Standard
TN 8th Tamil இயல் 2 - ஈடில்லா இயற்கை - மயங்கொலிகள் Important Questions And Answers Study Material - QB365 Set A
NEW8th Standard
TN 8th Tamil இயல் 2 - ஈடில்லா இயற்கை -பட்டமரம் Important Questions And Answers Study Material - QB365 Set A
NEW8th Standard
TN 8th Tamil இயல் 2 - ஈடில்லா இயற்கை - இயற்கையை போற்றுவோம் Important Questions And Answers Study Material - QB365 Set A
NEW8th Standard
TN 8th Tamil இயல் 1 - தமிழ் இன்பம் - ஆழிக்கு இணை Important Questions And Answers Study Material - QB365 Set A
NEW8th Standard
TN 8th Tamil இயல் 2-ஈடில்லா இயற்கை - திருக்குறள் Important Questions And Answers Study Material - QB365 Set A
Published on: 06/09/2019
Organisation of Life
Download Tamil Nadu 8th Standard Science question papers, model tests, one-mark questions, important questions, and public exam papers in PDF format. Free study materials and answer keys for TN State Board students.
Questions + Answers key
Take MCQ Science Test1.
The erythrocyte is placed in _________ solution which has lesser concentration of solutes and greater concentration of water than in the cytoplasm.
Hypotonic
Hypertonic
Neutral
Acidic
2.
Osmosis is the movement of water molecules from a ______.
Higher concentration to a region of lower concentration.
Lower concentration to a region of higher concentration.
Both of these
None of these
3.
The size of the cells are measured in units of __________.
4.
_______ nerve is located at the end of the eyes behind the retina.
5.
______ is a good example for anaerobic respiration.
6.
Differentiate between Osmoconformers and Osmoregulators?
7.
Name the processes by which air enters and comes out of our lungs?
8.
Mention the function of ‘Alveoli’?
9.
Tabulate the difference between aerobic and anaerobic respiration.
10.
Define Eukaryotic cell?
11.
Define Prokaryotic cell?
12.
Lists out the different types of metabolism with an example.
13.
Differentiate between inhalation and exhalation.
1.
(a)
Hypotonic
2.
(b)
Lower concentration to a region of higher concentration.
3.
( )
Micron
4.
( )
Optic
5.
( )
Yeast
6.
| Osmoconformers | Osmoregulators |
|---|---|
| Osmoconformers try to maintain the osmolality of their body matching with their surroundings. eg: Most of the invertebrates, marine organisms |
Organisms maintain their internal osmolaliry which canbe extremely different from that of the surrounding environment, through physiological processes. eg: Human |
7.
► Air enters in Inspiration
► Air comes out Expiration
8.
► Alveoli are the workhouses of respiratory system.
► The exchange of oxygen and carbondioxide takes place in alveoli.
► It takes up oxygen and gives out carbondioxide.
9.
| S.No | Aerobic | Anaerobic |
|---|---|---|
| 1. | Aerobic respiration takes Place in the presence of oxygen | 6139robic respiration takes place in the absence of oxygen |
| 2. | The end products of aerobic respiration are CO2 and H2O | The end products of anerobic respiration are CO2 ethanol and lactice acid |
| 3. | Common in all higher Plants and animals | Common in certain micro organisms and human muscle cell |
10.
In some of the organism like bacteria, cynobacteria, and mycoplasma, no true nucleus is seen. There organisims are called Prokaryotes.
11.
Prokaryotic cell lacks a distinct nucleus and membrane bound organelles
eg: bacteria.
12.
Metabolism is the sum total of the biochemical reactions which involves in release and utilisation of energy or energy exchange within the organisms.
It is divided into two types.
i) Anabolism
ii) Catabolism
i) Anabolism (Constructive metabolism):
► It is all about building and storing
► It supports the growth of new cells the maintenance of body tissues and the storage of energy for use in the future.
► During anabolism, small molecules are changed into larger more complex molecules of carbohydrate, protein and fat.
Eg: Glucose → Glycogen and other sugars.
Amino acids → Enzymes, hormones and proteins.
ii) Catabolism (Destructive metabolism
► It produces the energy required for all activity in the cells.
► In this process, cells breakdown large molecules (mostly carbohydrates and fats) to release energy
► This energy release provides fuel for anabolism, heats the body and enables the muscles to contract and the body to move.
► As complex chemical units are broken down into more simple substances, the waste products released in the catabolism are removed from the body through the skin, kidneys, lungs and intestines.
Eg: Carbohydrates → Glucose
Glucose → CO2 water and heat.
13.
| S.No | Inhalation | Exhalation |
|---|---|---|
| 1. | The muscles of the diaphragm | The muscles of the diaphram relax. |
| 2. | The diaphram goes downward. | The diaphram goes upwards |
| 3. | The ribs move upwards and outwards. | The ribs move downwards. |
| 4. | The volume of thoracic cavity increases. | the volume of thoracic cavity decreases. |
| 5. | air enteres the lungs through the nose | Air goes out of the lungs through the nose. |
8th Standard Syllabus & Materials
8th Standard
TN 8th Tamil இயல் 3 - கல்வி கரையில - பாடறிந்து ஒழுகுதல் Important Questions And Answers Study Material - QB365 Set A
NEW8th Standard
TN 8th Tamil இயல் 3-கல்வி கரையில - பல்துறைக் கல்வி Important Questions And Answers Study Material - QB365 Set A
NEW8th Standard
TN 8th Tamil இயல் 3-கல்வி கரையில - புத்தியைத் தீட்டு Important Questions And Answers Study Material - QB365 Set A
NEW8th Standard
TN 8th Tamil இயல் 2 - ஈடில்லா இயற்கை - தமிழர் மருத்துவம் ( நேர்காணல்) Important Questions And Answers Study Material - QB365 Set A
Tamilnadu Stateboard 8th Standard Subjects
Tamilnadu Stateboard Standards
