NCERT Solutions for Class 11 Psychology Chapter 3 the Bases of Human Behaviour

Ans : The evolutionary perspective explains the biological behaviour by indicating the physiological as well as behavioural changes that occur due to the evolutionary process. These are necessary for the survival of species. These evolutions have resulted due to the influence of environmental demands. Some behaviours play an obvious role in evolution. For example, the ability to find food, avoid predators, and defend one's young are the objectives related to the survival of the organisms as well as their species. Modern human beings possess some features for several thousand years. 
Three important features of modern human beings differentiate them from their ancestors: 
a bigger and developed brain with increased capacity for cognitive behaviours
ability to walk upright on two legs, and a free hand with a workable opposing thumb 


 

Ans : Neurons have dendrites, axon, soma and terminal buttons to transmit information. Dendrites receive the incoming neural impulses from adjacent neurons or directly from the sense organs in electrochemical form. The received signals are passed on to soma and then to axon so that the information is relayed to another neuron or to muscles. The axon conducts the information along its length. At the terminal point the axon branches into small structures, called terminal buttons which have the capability for transmitting information to another neuron, gland and muscle. 

Ans : The four lobes of the cerebral cortex and their functions are: 
Frontal lobe: It is mainly concerned with cognitive functions, such as attention, thinking, memory, learning, and reasoning. It also exerts inhibitory effects on autonomic and emotional responses. 
Parietal lobe: It is mainly concerned with cutaneous sensations and their coordination with visual and auditory sensations. 
Temporal lobe: It is primarily concerned with the processing of auditory information. It also helps in memorising symbolic sounds and words and understanding of speech and written language. 
Occipital lobe: It is mainly concerned with visual information. It also interprets visual impulses, memorises visual stimuli and helps in colour visual orientation. 

Ans : The endocrine glands play a crucial role in our behaviour. They secrete specific chemical substances, called hormones, which control some of our behaviours. The normal functioning of all hormones is crucial to our behavioural well-being. Without a balanced secretion of hormones, the body would be unable to maintain the state of internal equilibrium. Without the increased secretion of hormones during the times of stress, we would not be able to react effectively to potential dangers in our environment. Also, without the secretion of hormones at specific times in our lives, we would not be able to grow, mature and reproduce 

Ans : The autonomic nervous system controls activities which are normally not under direct control of individuals. It has two divisions: Sympathetic division and Parasympathetic division. It deals with emergencies when the action must be quick and powerful, such as in situations of fight or flight. During this period, the digestion stops, blood flows from internal organs to the muscles and breathing rate, oxygen supply, heart rate, and blood sugar level increases.