Tag: biology : an introduction

Bacteria are single-celled organisms that exhibit a cellular level of organization. Viruses are generally considered non-cellular, while animals and plants exhibit tissue or organ-system levels of organization.

Viruses are obligate parasites. They are acellular and are only made of a genetic material surrounded by a protein capsid. Viruses use the host cellular machinery for survival and replication. They also undergo mutation within the host. They have no energy metabolism nor do they produce waste products. Hence they are considered non-living. Thus the correct answer is option C.

The human body typically has 206 bones (not 200) and 33 vertebrae (not 30). Since the other options contain incorrect information, 'None of these' is the correct choice.

The living organisms are made up of the cells in which the atom forms the basis of all the structures in the cells like the proteins, lipids, fats, nucleic acids, etc. The living organisms are composed of cells, tissues, and ATP as the common source of energy. The non-living things are made up of the atoms which form the material. 

The living organisms are composed of cells which form the tissues. The tissues when damaged are repaired and replaced by the new cells. Irritability is the ability of an organism to respond to the external stimulus. The organism exhibit movement on receiving the stimulus from the internal or the external environment. The most common example of irritability is shown by the Mimosa plant which folds the leaflets on stimulus with touch. 

• Homoeostasis is the process that helps to maintain an equilibrium between the processes or the concentration of the fluid inside and outside the body.
• The process of homeostasis can be achieved by morphological adaptation in the form of gills or through physiological adaptation by a change in temperature or through behavioral adaptation to survive in extreme conditions. 

Reproduction is a process of producing offsprings from parents. It can be sexual, asexual or vegetative. Only sexual reproduction involves the fusion of gametes. It ensures continuity of a species by producing its own kind and also a transfer of genes in further generations.

Changes in structure and function of living beings is called as development. Development is important in an organism for in survival in the competition of nature. Development leads to adaptations that increase the chances of survival of an organism.