Tag: introduction to tissues

1. Cytology is the branch of biology that deals with the structure of a cell.
2. Histology is the branch of biology that deals with the study of microscopic anatomy or tissue.
3. Morphology is the study of structure discernible with a naked eye.

Extracellular matrix is the network of macromolecules like collagen, enzymes etc, which provide structural support to the cells. They help in the formation of tissues and organs. Extracellular matrix functions as cell adhesive as they are helpful in the interaction between cells and matrix.

• Hairs and nails are made of dead tissues. Only the base of the hair and the base of the nail are living. 
• The dead tissues are devoid of the nerve supply which acts as messengers to convey the sensation of pain and in their absence, it cannot be perceived by our brain. 
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• Thus, the correct answer is option A.

The basic unit of ecological hierarchy is individual because a community starts building from an individual which grows onto form an entire ecosystem. 

The biosphere is made up of the parts of Earth where life exists, but there is uneven distribution of living organisms in the biosphere. The biosphere extends from the deepest root systems of trees, to the dark environment of ocean trenches, to lush rain forests and high mountains.
Scientists describe the Earth in terms of spheres - Lithosphere, Atmosphere, Hydrosphere. Since life exists on the ground, in the air, and in the water, biosphere overlaps all these spheres. Biosphere has existed for about 3.5 billion years.

A.An organism is an individual living thing. It can be as simple as a single-celled Amoeba or it can be as complex as a human being.
B.A tissue is a collection of structurally similar cells acting together to perform a specific function.
C.An organelle is a small constituent of a cell that has a specific function. For example, mitochondria (called as powerhouse of the cell) aids in generating energy for cell functions.
D.An organ is a group of tissues that performs a specific function. For example, stomach and kidney are organs. 

The biosphere is a global ecosystem composed of living organisms (biotic) and the nonliving (abiotic) factors from which they derive energy and nutrients. It is a relatively thin life-supporting stratum of Earth's surface, extending from a few kilometres into the atmosphere to the deep-sea vents of the ocean.