Maharashtra Board Class 7 Science Cell Structure and Microorganisms Textbook BackPage Exercises which includes Fill in the blanks ,Question Answers and Extra Question and Answers from the Chapter.
Fill in the blanks with the proper word.
- The organelle called the chloroplast is present in plant cells only.
- Garbage is converted into manure by micro-organisms.
- In the cell, photosynthesis is carried out with the help of chloroplasts.
- An electron microscope is necessary for the study of cell organelles.
Answer the following questions.
What is a ‘cell’ ?
A ‘cell’ is the basic structural and functional unit of all living organisms. It is the smallest unit of life and the building block of complex organisms.
Name the different organelles in a cell ?
Different organelles in a cell include the nucleus, endoplasmic reticulum, Golgi bodies, lysosomes, mitochondria, vacuoles, plastids (plant cells), cell wall (plant cells), plasma membrane (animal cells), and cytoplasm.
What are micro-organisms ?
Micro-organisms are tiny, living organisms that are too small to be seen with the naked eye. They can only be observed under a microscope. These organisms include bacteria, viruses, fungi, protozoa, and algae.
Which are the different types of micro-organisms ?
The different types of micro-organisms include Bacteria, Viruses, Fungi, Protozoa, Algae.
Give reasons.
Diseases spread on a large scale during periods of heavy rainfall and floods.
Floods and heavy rainfall spread diseases because:
- Water sources can become contaminated with sewage and pathogens due to heavy rainfall and flooding.
- Disease-carrying vectors like mosquitoes and flies may spread in flood waters.
- Overcrowding in temporary shelters during floods can spread diseases.
There is a possibility of food poisoning if we eat stale food.
