CBSE: Check important extra questions for CBSE Class 9 exam 2020-21 (Chapter 6 - Tissues). These questions are based on the Class 9th Science NCERT textbook and one can easily attempt these questions in less than 5 minutes. These questions are also important for CBSE Class 9 Science exam 2020-21.
CBSE Class 9 Science Exam 2020-21: NCERT Based Important Extra Questions (With Answers) Chapter 6 - Tissues
Question: Write the name of three types of muscle tissues?
Answer:
Striated, unstriated and cardiac are three types of muscle tissues.
CBSE Class 9 Revised Syllabus for 2020-2021
Question: Why do animals of colder regions and fishes of cold water have a thicker layer of subcutaneous fat?
Answer: It is because fat acts as subcutaneous insulation of the body for thermoregulation.
Question: Explain why a potted plant covered with a glass jar has water vapours appearing on the wall of the glass jar.
Answer:
It is due to the phenomenon of transpiration.
Question: Explain the difference between voluntary & involuntary muscles with an example?
Answer:
Voluntary muscles can be influenced by conscious will when we want them to move. The most common example is muscles of limbs or skeletal muscles.
Whereas involuntary muscles function on their own. One can't start or stop them from working by our desire. Some of the most common examples are cardiac muscles and smooth muscles.
Question: Explain why water hyacinth floats on the water surface.
Answer:
It is due to aerenchyma present in the swollen petiole.
Question: Explain why epidermis is important for the plants.
Answer:
The epidermis is important for plants because it gives protection & helps in gaseous exchange. It also checks water loss and root hairs arising from epidermis helps in absorption of water and minerals.
Question: Explain the process of differentiation.
Answer:
The loss of ability to divide by taking up a permanent shape, size and function is called differentiation.
Question: Explain how corks are formed and what is their role.
Answer:
As plants grow older, a strip of secondary meristem replaces the epidermis of the stem. Cells cut on the outer side by this meristem are called cork. They are protective in function for older stems (twigs or branches). They are impervious to gases and water.
Question: Differentiate between xylem and phloem?
Answer:
Xylem transport water and minerals vertically from soil to aerial parts of the plant, whereas Phloem transport food from leaves to other parts of the plant.
Question: Xylem transports ____X___ and ____Y___ from soil.
(a) X ⇒ Water & Y ⇒ Minerals
(b) X ⇒ Air & Y ⇒ Minerals
(c) X ⇒ Air & Y ⇒ Water
(d) X ⇒ Soil & Y ⇒ Nutrients
Answer:
(a) X ⇒ Water & Y ⇒ Minerals
CBSE Class 9 Science Exam 2020-2021 - Check Extra Questions and Answers for All Chapters
