Tissues Test - 25

Sclerenchyma is entirely composed of dead cells. Tissues mentioned in others options are composed of living cells only.

Apical and intercalary meristems are not permanent tissues but they are meristematic tissues which remain in continuous state of division. These tissues differentiate to give rise to the permanent tissues.

Other meristems in options facilities growth in length, while lateral meristem cause the organ to increase in diameter and growth which happens in the case of girth.

Companion cells are narrow, elongated, thin-walled, living cells. They lie on the sides of the sieve tubes and are closely associated with them through plasmodesmata. Companion cells do not possess perforated cell walls.

Epithelium in option ‘a’ is present in skin and that in option ‘d’ is meant for structural support. Columnar epithelium facilities absorption. It is responsible for secreting mucus and digestive enzymes in the intestine.Tissue in option ‘c’ is not a type of epithelium.

Ligaments join one bone to another bone and hence ligament break can result in dislocation.

Skeletal muscles or striated muscles are found in the body wall and the limbs (biceps and triceps of arms, legs). The contraction and relaxation of these muscles are under the control of organism, so they are also called voluntary muscles. These are attached to the bones by tendons. When they contract, they pull the tendon to move the bones and help in the movement of limbs.

Skeletal muscles are voluntary. They are also striated. Smooth muscles and cardiac muscles are involuntary and are not under our control.

Meristematic tissues are groups of living cells which are localised at specific parts in the plant body and divide continuously to add new cells.

Conduction of water is a function of the xylem tissues and not of epidermis.

Tendons are white fibrous connective tissues having great strength and join skeletal muscles with bones.

Kidney is composed of different kinds of epithelial tissues.

Another name of adipose tissue is fat tissue which is composed of adipocytes.

Bone is a very strong and non- flexible vertebrate connective tissue which forms the framework that supports the body. The bone matrix contains both inorganic and organic substances. The inorganic salts present in the matrix are mainly phosphates and carbonates of calcium and magnesium e.g. calcium phosphate, calcium carbonate, magnesium phosphate etc.

Muscular tissue consists of muscle fibres and is responsible for movement in the body. Muscles contain special proteins called contractile proteins, which contract and relax to cause movement.

Movement of organs in other options is not controlled by individual voluntarily. Hence, voluntary muscles are not found in them.

The nervous tissue, which contains densely packed nerve cells, called neurons (Gk. neuro = nerve), is present in the brain, spinal cord and nerves. The neurons are specialised for conduction of nerve impulses. Tendon is a type of connective tissue.

Tendon is a type of fibrous connective tissue, where as nerve cells compose the nervous tissue.

Areolar connective tissue is the most widely distributed connective tissue is animal’s body. It is found between the skin and muscles, around blood vessels and nerves, and in the bone marrow. It fills the space inside the organs, supports internal organs and helps in repair of tissues.

This is the reason our heart keeps on pumping the blood throughout the life. Other types of muscles work as and when required because they do not need to work continuously.