Tissues refer to a group of similar cells that perform a particular function. In vertebrates, the tissues are orgainzed into four types called the epithelial tissues, muscle tissue, connective tissue and the nervous tissue.
Epithelial tissue refers to the tightly packed group of cells covering the body outside, lining the body cavities and glands. Based on the shape, it is classified into squamous (flat), cuboidal and columnar. It can be single layered (simple) or stratified (multilayered). It protects the body, helps in the absorption of nutrients and elimination of wastes.
Muscle tissue is made up of the muscle cells that coordinate and bring movement and locomotion. It is made up of muscle fibres and the proteins called the actin and myosin. Muscle tissue is of three types-
(a) Skeletal muscle tissue is a striated tissue which is under the voluntary control.
(b) Smooth muscle tissue found in the walls of the blood vessels, digestive tracts and other parts of the body and are involuntary in nature.
(c) Cardiac tissue is an involuntary, straited tissue found in the walls of the heart.
Connective tissue contain cells present in an extracellular matrix connecting tissues, giving shape to the organs and holding them in place. It can be classified into loose connective tissue found throughout the body, dense connective tissue found in the bones and the ligaments and fluid connective tissue of the blood.
Nevous tissue is the tissue involved in control and coordination of the body. It helps in transmission of messages in the form of nerve impulse with the help of the structural and functional unit of the nervous system called the neurons.
Bacteriophages infect a cell by injecting DNA into the host cell. true or false?
The answer is true!
Hope this helps!
Answer:
1. by spraying them with insecticide
2. sucking the blood of animals and humans
Explanation:
In the first statement, it is said that the tsetse flies can be controlled by sterilizing. The statement form is similar to the first option where the verb of the sentence is is in the same tense and the subject of the sentence comes after the present continuous verb form.
Likewise, in the second sentence the verb tense coincides with the second sentence i.e option B
Hence the correct answers are
1. by spraying them with insecticide
2. sucking the blood of animals and humans
Answer:
Primary producers are organisms that acquire their energy from sunlight and materials from nonliving sources. Algae, higher plants, and some bacteria and protists are important autotrophs in running waters. Heterotrophs obtain energy and materials by consuming living or dead organic matter.
The Greenhouse Effect in Nature
However, only around 12% of the solar energy that enters the atmosphere is directly lost to space. When greenhouse gas molecules absorb thermal infrared energy radiated by the surface, a net 5-6 percent of incoming solar energy is transported to the atmosphere.
