Q1: What is a tissue?
Ans: A tissue is a group of cells similar in structure that work together to perform a specific function. The formation of different types of tissues leads to the division of labour in the body.
Q2: Name the three types of meristematic tissues in plants.
Ans: The three types of meristematic tissues are apical meristem, lateral meristem, and intercalary meristem.
Q3: What is the function of apical meristem?
Ans: Apical meristem is present at the tips of roots and shoots. It helps plants grow in length by continuous cell division.
Q4: What is the function of lateral meristem?
Ans: Lateral meristem is present along the circumference of stems. It helps plants increase in girth or thickness by producing new cells inside and outside in a concentric manner.
Q5: What is differentiation in plants?
Ans: Differentiation is the process by which meristematic tissue becomes specialised to perform specific functions such as support, transport or storage, and becomes permanent tissue.
Q6: What is the cuticle in plants and what is its function?
Ans: The cuticle is a waxy layer of cutin that covers the epidermal cells. It reduces water loss through transpiration and also protects the plant against mechanical injury and invasion by parasites.
Q7: What are stomata and what is their function?
Ans: Stomata are pores present in the epidermis of leaves. They help in gaseous exchange and in transpiration, which also helps in water transportation through the xylem.
Q8: What is sclerenchyma and where is it found?
Ans: Sclerenchyma consists of cells with thick walls due to deposition of lignin, making them hard and strong. It is found in stems, leaf veins, and hard coverings of seeds and nuts such as coconut husk and walnut shell.
Q9: What is the difference between xylem and phloem?
Ans: Xylem transports water and minerals from the roots to other parts of the plant. Phloem transports food prepared in the leaves to other parts of the plant.
Q10: Name the three plant tissue systems.
Ans: The three plant tissue systems are the dermal tissue system, the ground tissue system, and the vascular tissue system.
Q11: What are the four main types of animal tissues?
Ans: The four main types of animal tissues are epithelial tissue, connective tissue, muscular tissue, and nervous tissue.
Q12: What is connective tissue? Give two examples.
Ans: Connective tissue is a tissue that connects and supports other tissues and organs of the body. Blood and bones are both examples of connective tissue.
Q13: What is the difference between a tendon and a ligament?
Ans: A tendon connects muscles to bones and brings about movement. A ligament connects bone to bone, provides stability, limits movement, and helps prevent dislocation.
Q14: What are the three types of muscle tissue?
Ans: The three types of muscle tissue are skeletal muscle, smooth muscle, and cardiac muscle.
Q15: Why are cardiac muscles unique?
Ans: Cardiac muscles are found only in the heart. Their fibres are cylindrical and branched with a single nucleus, and they work tirelessly and rhythmically throughout life without fatigue.
Q16: What is a neuron and what are its three main parts?
Ans: A neuron is the basic cell of nervous tissue specialised to receive, process and transmit messages. Its three main parts are the cell body, dendrites, and axon.
Q17: What is the musculoskeletal system?
Ans: The musculoskeletal system is made up of bones, muscles, joints, cartilage, tendons, and ligaments. It helps us stand upright, move, maintain posture, and protect delicate organs.
Q18: What is a ball and socket joint? Give one example.
Ans: A ball and socket joint is formed when the rounded top of one bone fits into a shallow hollow of another bone. The shoulder joint is an example, and it allows movement in all directions.
Q19: What are fixed joints? Give an example.
Ans: Fixed joints are joints where the bones cannot move at all. The bones of the skull are connected by fixed joints, which keep the brain safe even when the body moves.
Q20: What is the function of the rib cage?
Ans: The rib cage acts like a protective cage to protect vital organs such as the heart and lungs. It can expand and contract during breathing because the ribs are joined by flexible cartilage.