Category: Biology Questions
Mechanism of Hearing: The sound waves from the external environment are perceived by the external pina and are transmitted to the fenestra vestibuli (oval window) through the eardrum and auditory ossicles. The auditory vesicles amplify the sound vibrations and the eustachian tube serves to equalize the pressure on the sides of the tympanic membrane. The fenestra …
Perceive the Colour of an Object: The retina of the eye contains two types of photoreceptor cells, namely rod and cones. Cones perform the function of vision in daylight (scotopic) as well as colour vision. There are three types of cones, which possess their own characteristic photopigments that respond to red, green and blue. Various combinations …
Role of Bacteria in Medicines: Bacteria played an important role in the manufacturing of medicines. These are- (1) Antibiotics- These are organic substances obtained from living organisms. These substances kill or inhibit the growth of other organisms. Gramicidin, Tyrothricin, Subtilin and Bacitracin are some of the antibiotics obtained from bacteria. But none of these has been …
Process of the Nitrogen Cycle: Nitrogen Cycle is an important Biogeochemical Cycle. Nitrogen makes up 78.1% of the atmosphere by volume, so the atmosphere is a vast storage pool in this cycle. Carnivores feed on herbivores that, in turn, feed on plants. When animals defecate, this waste material is broken down by worms and insects, mostly …
Epithelial Tissue: Epithelial tissue or epithelium is a fundamental animal tissue that is made of one or a few layers of compactly arranged cells overlying a basement membrane that covers the external and internal surfaces of various body parts. The term was coined by Ruysch. Functions of Epithelial Tissue: Protection- The basic function of epithelial tissue …
Connective tissue: Connective tissue is mesodermal in origin and form of matrix, fibres and cells. It constitutes the extracellular ground substance and fills up the intercellular spaces between the cells. Functions of Connective tissues: Connective tissue is basically a binding and a packaging tissue but has many other important functions as well- A type of connective …
Hybridization in Plants: Hybridization is the method of producing new crop varieties by crossing two genetically different parents. As a result of hybridization, the desirable characters of two or more species or varieties are combined together or are transformed from one to the other. Hybridization increases genetic variability. Uses of Hybridization: The main purpose of hybridization …
What is Synapse? Synapse (also called interneural) is the connection between the axon of one neuron and the dendron of other neuron having a gap of 200 Å. Nerve Impulses travel from axon to dendron as one-way traffic or unidirectional transmission. The end of the axon forms the pre-synaptic neuron (before synapse) and the tip of …
Compare the Choroid and Retina in Human Eye: Choroid- It lies inside the sclera. It contains a network of blood vessels supplying food and oxygen to the eye. It is deeply pigmented and is connected in front to a thick structure called the ciliary body. It bears blood vessels and muscle fibres which run in a …
Genetic load: Genetic load is a measure of the number of disadvantageous genes in a population or of the damage done to the population by certain genetic factors. Disadvantageous genes reduce fitness by mortality, morbidity or sterility in heterozygotes, if the gene is dominant and in homozygotes, if it is recessive. Thus, it is related to …
