Moulds on bread may look unpleasant but fungi benefit society greatly. Class 9

Moulds on bread may look unpleasant but fungi benefit society greatly. Class 9

Bridging Science and Society

Question 1.

Moulds on bread may look unpleasant but fungi benefit society greatly. Fungi grow very fast by spore formation and degrade organic wastes and pollutants. Fungi also play an important role in removal of heavy metals from industrial wastes. Many antibiotics are derived from fungi (penicillin and amoxicillin), saving countless lives from bacterial infections. Do you know any fungus that can degrade plastic? (Page 212) Class 9

Answer:

Yes, some fungi such as Aspergillus and Penicillium are known to degrade certain types of plastics. These fungi produce enzymes that can break down plastic materials, making them useful in reducing plastic pollution and managing waste.

Threads of Curiosity (Page 221)

Question 1.

What determines a baby’s biological sex? So far, you have learnt that every person has two sex chromosomes. Females have XX and males have XV chromosomes. The mother always contributes an X chromosome to a baby and the father contributes either an X (Female: XX) or a Y (Male: XY) chromosome. Now, from the above information, can you predict who determines the sex of a baby? Class 9

Answer:

The biological sex of a baby is determined by the father. This is because the mother always contributes an X chromosome, while the father can contribute either an X or a Y chromosome. If the father contributes an X chromosome, the baby will be female (XX), and if he contributes a Y chromosome, the baby will be male (XY). Thus, the type of chromosome contributed by the father determines the sex of the baby.