The Invisible Living World: Beyond Our Naked Eye
Short Questions
1. What is the smallest unit of life?
Answer: Cell
2.Who invented the microscope?
Answer: Robert Hooke
3. What is the outer layer of a plant cell called?
Answer: Cell wall
4. What is the function of the nucleus in a cell?
Answer: It controls cell activities.
5. What is the name of the scientist called the Father of Microbiology?
Answer: Antonie van Leeuwenhoek
6. What is the green pigment in plant cells called?
Answer: Chlorophyll
7. What are organisms made of one cell called?
Answer: Unicellular
8. What gas do microalgae release during photosynthesis?
Answer: Oxygen
9. What is the name of the book published by Robert Hooke?
Answer: Micrographia
10.What is the role of yeast in bread making?
Answer: It produces carbon dioxide to make dough fluffy.
11. What is the liquid part of a cell called?
Answer: Cytoplasm
12. Which microorganism helps in curd formation?
Answer: Lactobacillus
13. What is the largest known cell?
Answer: Ostrich egg yolk
14. What do microorganisms in soil do to plant waste?
Answer: They decompose it into manure.
15.What is the name of the bacteria that fixes nitrogen in legume roots?
Answer: Rhizobium
Long Questions
1. How did the invention of the microscope change our understanding of living things?
Answer: The microscope revealed tiny organisms and cells invisible to the naked eye. It helped scientists understand the structure and function of life at a microscopic level.
2.What are the main differences between plant and animal cells?
Answer: Plant cells have a cell wall, chloroplasts, and large vacuoles, while animal cells do not. Animal cells have small or no vacuoles and lack chloroplasts.
3.Why are microorganisms important for the environment?
Answer: Microorganisms decompose waste into nutrient-rich manure, recycling nutrients. They help clean the environment and support plant growth.
4.How does yeast help in making bread and cakes?
Answer: Yeast ferments sugar, releasing carbon dioxide that makes dough rise. This makes bread and cakes soft and fluffy.
5.What is the role of the cell membrane in a cell?
Answer: The cell membrane controls what enters and leaves the cell. It protects the cell and allows essential materials to pass through.
6.How do bacteria like Rhizobium benefit plants?
Answer: Rhizobium bacteria live in legume root nodules and fix nitrogen from the air. This provides nutrients to plants, improving soil fertility.
7.What happens to milk when Lactobacillus bacteria act on it?
Answer: Lactobacillus ferments lactose in milk, producing lactic acid. This turns milk into sour curd.
8.Why do nerve cells have a unique shape?
Answer: Nerve cells are long and branched to carry messages quickly. Their shape helps them connect different parts of the body.
9.How do microalgae contribute to the environment?
Answer: Microalgae produce oxygen through photosynthesis and serve as food for aquatic animals. They also help clean water and can be used as biofuel.
10.What are the levels of organization in living organisms?
Answer: The levels are cell, tissue, organ, organ system, and organism. These show how cells work together to form a complete living being.
Very good answers