What is cell differentiation?

Mention the function of ‘Alveoli’?

Differentiate between Osmoconformers and Osmoregulators?

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 playground daily and play football or basketball. She also advised to do pranayamam in the morning.
a) Why did the doctor advised him to go to the playground?
b) What is the use of pranayamam?

Shylesh is a school going kid studying standard VIII. He is crazy about playing video games in mobile phones. After 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 consult an eye doctor.
i) How does excessive usage of mobile phone affect our eyes?
ii) What are the values shown by the teacher?