AP BIOLOGY

Detailed explanation-1: -Sieve cell is a part of phloem tissue. They are elongated cells with minute pores. They do not have a nucleus at maturity. They help in the transportation of food prepared in the leaves to other parts of the plant.

Detailed explanation-2: -The elongated cells or spindle are cellular structures of elongated size with diverse functions, among the main the constitution of muscular tissue. Examples are smooth muscle cells and nerve cells.

Detailed explanation-3: -Neural tissue is made up of elongated cells called neurons. A neuron (nerve cell) is the basic building block of the nervous system. It is specialised to transmit information in the form of electrical impulses throughout the body. It contains elongated cells to communicate with the distant parts of the body.

Detailed explanation-4: -Companion cells are large elongated cells of phloem with large nucleus. It is attached to the lateral side of sieve tubes. These cells help in transport of food along with sieve. These are specifically found only in angiosperms.

Detailed explanation-5: -companion cell A type of cell found within the phloem of flowering plants. Each companion cellis usually closely associated with a sieve element. Its function is uncertain, though it appears to regulate the activity of the adjacent sieve element and to take part in loading and unloading sugar into the sieve element.