Organisation of Living World Test - 3

Sieve tubes are living and non–nucleated at maturity.The main function of the sieve tube is transport of carbohydrates, primarily sucrose, in the plant (e.g., from the leaves to the fruits and roots).

Collenchyma occurs in the climbing stems. They provide structural support, protecting the plant by serving as an inner framework. Plants are exposed to numerous structural challenges and without these cells, most plants would be too fragile to withstand the damage caused by heavy rains, high winds and other stresses.

Primary wall is elastic due to the absence of lignin. Lignin is water-resistant. It reinforces cell walls, keeping them from collapsing.

Vessels do not have end walls.The cells are arranged in longitudinal series in which the partitioned walls (transverse walls) are perforated, so the entire structure looks-like a water pipe. Their main function is transport of water and minerals. It also provides mechanical strength.

Blood, bones and cartilage are examples of connective tissue.Connective tissue is one of the four types of biological tissue that supports, connects, or separates different types of tissues and organs in the body. The other three types are epithelial, muscle, and nervous tissue.

Each tissue consists of cells, which are similar in origin and form, and perform the same function.

The variety of tissue using the greatest amount of energy in a living system is muscular tissue. Muscles store energy for their own use in the form of glycogen, which represents about 1% of their mass. Glycogen can be rapidly converted to glucose when more energy is necessary.

A tissue is a group of cells having similar structure and function.Organs are then formed by the functional grouping together of multiple tissues.

Blood is a type of connective tissue for two basic reasons: (1) embryologically, it has the same origin (mesodermal) as do the other connective tissue types and (2) blood connects the body systems together bringing the needed oxygen, nutrients, hormones and other signaling molecules, and removing the wastes.

Hind limb contains voluntary muscles whose action is normally controlled by an individual's will.