Plant and Animal Tissues

 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).

 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.

 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.

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

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

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

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.

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

 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.

The total number of muscles in the body of a human being is 639. 

Tendons and ligaments belong to connective tissues. Ligaments connect two or more bones together and help stabilize joints. Tendons attach muscle to bone. Tendons vary in size and are somewhat elastic and attach bones to muscles.

Tracheids are elongated cells in the xylem of vascular plants that serve in the transport of water and mineral salts. Tracheids are one of two types of tracheary elements, vessel elements being the other.

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.

In sclerenchyma, wall is lignified. Due to lignification, the cells lose their living characters at maturity.

 Sieve tubes are suited for translocation of food because of broader lumen and perforated cross walls. 

 In aquatic plants, parenchyma cells have star like air cavities in between the cells. They are called aerenchyma. The air trapped in the cavities make the plants lighter in weight and help them to float in water.

 Collenchyma is a mechanical tissue with unlignified walls.These cells are often found under the epidermis, or the outer layer of cells in young stems and in leaf veins.

Stripped muscles are attached to bones except in tongue. This exception is also seen in upper part of oesophagus.

 Both muscular and skeletal systems protects the internal organs of the body.The muscles of the muscular system keep bones in place; they assist with movement by contracting and pulling on the bones.