CBSE Class 9 Science Tissues Plants Worksheet

Exam Questions NCERT Class 9 Science Chapter 6 Tissue

Question: What are protective tissues?
Answer : All parts of plants, e.g. leaves, flowers, stem, and root are covered by a single outermost protective layer called epidermis. It consists of rectangular, closely fitted relatively flat cells which lack intercellular spaces. Usually it is one cell thick and is covered with cutin. Epidermis protects internal tissues of the plant. In old dicot plants, epidermis is replaced by secondary meristem which cuts cells toward outerside. Cork cells do not have intercellular spaces and are dead cells. The walls of cork cells are heavily thickened due to the position of suberin. Presence of suberin makes the cells impervious to gases and water and thus prevents evaporation of water.

Question: Where can we find apical meristem?
Answer : It is found in the growing tips of roots and stem. The length of roots and stem is increased due to the presence of apical meristem.

Question: What is the structure of a neuron?
Answer : Building block of a nervous tissue is a neuron. It has a thread-like structure with axon and cell body.

Question: Explain the structure of a fluid connective tissue.
Answer : Blood is a fluid connective tissue. Blood consists of :
1. Blood plasma,
2. Blood cells.
1. Blood plasma : It is the fluid matrix which contains 85 to 95% water, 7% different types of proteins, 0.9% of salts, about 0.1% glucose and a very small amount of hormones, wastes, etc. In the plasma, blood corpuscles (cells) are suspended.
2. Blood cells : Three kinds of blood cells are found suspended in the blood plasma. These are :
(i) Red blood corpuscles (Erythrocytes) or RBCs (ii) White blood corpuscles (leucocytes) or WBCs and
(iii) Blood platelets. (i) Red blood corpuscles (Erythrocytes) or RBCs : The red blood corpuscles are biconcave, disc-like cells which are devoid of nucleus. They contain a substance called haemoglobin because of this they appear red in colour. The most important function of the RBCs is the transport of oxygen and carbon dioxide. (ii) White blood corpuscles (Leucocytes) or WBCs : These cells are comparatively large in size, colourless and irregular in appearance. They are devoid of haemoglobin. They protect our body from diseases by destroying germs. (iii) Blood platelets : These are small, 2-4 m in diameter. They are without nucleus. Their main function is to liberate some substances which helps in blood clotting.

Question: What will happen if apical meristem is damaged?
Answer : Growth of plant in length will stop. 

Question: Mention the functions of bone.
Answer : (i) Provides support to skeletal (ii) Provides shape to body (iii) Protects the internal organs (iv) Support muscles

Question: How is ligament different from tendons?
Answer : Ligaments are elastic connective tissue which attach bone to bone to keep them in their place. Tendons are less elastic connective tissues which attach muscles to a bone.

Question. _____ tissues make the coconut husk.
Answer : Sclerenchymatous tissue

Question: Define guard cells.
Answer : Guard cells are kidney-shaped epidermal cells and a pair of these cells bound each stomata.