Samacheer Kalvi solutions for Science [English] Class 8 TN Board chapter 18 - Organisation of Life [Latest edition]

______ is tough and thick white sheath that protects the inner parts of the eye.

______ cells are specialised cells that can be transformed into any kind of cells.

Maintenance of constant internal environment of the body is known as _________.

In the absence of oxygen, glucose is broken down into ________.

The process of air passing in and out the lungs is called ________.

Osmosis is the movement of water molecules from ______.

The erythrocyte is placed in _______ solution which has lesser concentration of solutes and greater concentration of water than in the cytoplasm.

______ is the structural and functional unit of living organisms.

The largest cell is egg of an _______.

_______ is a good example for anaerobic respiration.

______ nerve is located at the end of the eyes behind the retina.

The size of the cells is measured in units of ______

Match the following.

In hypotonic condition, concentration of the external and the internal solution of the organism are same.

Diffusion is the movement of particles from an area of lower concentration to higher concentration.

Human beings are warm-blooded in nature.

The larynx has fold of tissue which vibrate with the passage of air to produce sound.

Aqueous humour plays an important role in maintaining the shape of the eye.

What is cell differentiation?

State different types of tissues.

Mention the function of ‘Alveoli’.

Name the processes by which air enters and comes out of our lungs.

Differentiate osmoconformers and osmoregulators.

Define - Metabolism.

Define - Prokaryotic cell.

Tabulate the differences between aerobic and anaerobic respiration.

Why the human eye is compared with camera?

Which organ and organ system help to maintain homeostasis?

Draw the struture of human eye and label its parts.

Explain osmosis with an example.

Differentiate between inhalation and exhalation.

List out the different types of metabolism with an example.

Explain the mechanism of breathing.

Why do we need instant energy? Does glucose give that energy? Explain.

How are we preparing pickles? What are the steps involved in that?

Dr. Usha is a pulmonologist (Doctor for respiratory diseases). One day, a school student named Arjun, met her with respiratory problems. After diagnosis, the doctor advised him to go to playground daily and play football or basketball. She also advised him to do pranayamam in the morning.

1. Why did the doctor advise him to go to the playground?
2. What is the use of pranayamam?

Explain why you are not able to breathe normally when you are in closed and crowded places?

Shylesh is a school-going kid studying standard VIII. He is crazy about playing video games on mobile phones. After a couple of months, his eyes turned red and he felt severe pain in his eyes. His science teacher enquired about this and advised his parents to take him to an eye doctor.

1. How does excessive usage of mobile phone affect our eyes?
2. What are the values shown by the teacher?