Chapter 2. Bases of Human Behaviour Textbook Solutions

NIOS Class 12 Psychology Chapter 2 Answers

INTEXT QUESTIONS 2.1

Match the following.

1. Smallest unit of nervous system	A. Dendrite
2. Receives messages from other neurons	B. Myelin Sheath
3. Structure on which neurons develop & work	C. Bipolar
4. Helps in conduction of message	D. Neuron
5. A type of neuron	E. Glial Cells

Ans: (1-D), (2-A), (3-E), (4-B), (5-C)

INTEXT QUESTIONS 2.2

One-Word Answers

1. Name the part of the neuron that receives messages from adjacent cells.

Ans: Dendrite

2. The neurons of the motor pathway control ________.

Ans: Voluntary muscles

3. Name the cell which is responsible for the reproduction of other cells of the body.

Ans: Stem cells

4. Damage to which brain part may lead to difficulty in heart rate and breathing?

Ans: Medulla

5. Damage of which part of brain may lead to difficulty in forming new memories?

Ans: Hippocampus

INTEXT QUESTIONS 2.3

Fill with suitable answers

1. Endocrine glands release ______ in blood stream.

Ans: Hormones

2. Pineal gland is placed near the base of ______.

Ans: Cerebrum

3. ______ are male gonads.

Ans: Testes

4. Insulin is secreted in blood stream by ______.

Ans: Pancreas

5. Metabolism is controlled by ______.

Ans: Thyroxin

INTEXT QUESTIONS 2.4

Fill in the blanks with suitable answers

1. At the beginning stage of the new life. Zygote has _______ pairs of chromosomes.

Ans: 23

2. __________ and _________ interplay determines our physical and psychological makeup.

Ans: Heredity and environment

3. The Bronfenbrenner’s model focuses on interconnection between the _________ and the environment at various levels.

Ans: Individual

State whether these statements are True or False.

1. The Bronfenbrenner’s model has been divided into three levels.

Ans: False

2. The exposure to harmonious, violent, and funny content on television influences a growing child through imitation.

Ans: True

3. Genes are the codes or commands that are responsible for the physical and psychological development of the offspring.

Ans: True

TERMINAL EXERCISE

1. Discuss the function of neurons and their structural composition.

Ans: Structural composition of neurons

The part of the neuron that receives messages from other cells is called the dendrites (branches).
The dendrites are attached to the soma (cell body), which contains the nucleus and keeps the entire cell alive and functional.
As we move further, we follow the axon, a fibre-like structure attached to the soma, whose job is to carry messages to other cells (to other neurons, muscles, or glands).

Functions of Neurons:

Neurons function based on “All or None” law.
Depending upon the stimulus intensity, i.e., if it reaches a critical value, it will fire with total strength, if below, then there will be no excitation.
So, nerve impulses are electrical events of very short duration that move along the axon. During this transaction, when the neuron is not conducting any impulse, i.e. resting, the inside of the membrane has a negative electrical charge.
When the cell membrane is excited by the stimulus, the cell becomes a little less negative on the inside. As the stimulus reaches a threshold level, the membrane changes its characteristics- certain channels open to allow sodium from outside to enter the cell.

2. Describe the process involved in information transmission between neurons.

Ans:

When the cell membrane is excited by the stimulus, the cell becomes a little less negative on the inside.
As the stimulus reaches a threshold level, the membrane changes its characteristics- certain channels open to allow sodium from outside to enter the cell.
Since sodium ions are positively charged, the inside of the cell becomes momentarily positive (for a millisecond). This results in a nerve impulse.
After a millisecond, to restore the potential, potassium ions move out to neutralise charges (sodium-potassium pump).
In an axon, the active portion triggers a spike (nerve impulse) in the next region and so on down the axon.
Once the potential has been restored at the point of initial activity, it becomes ready to carry another impulse from a subsequent stimulation.

3. Why are psychologists concerned with the role of heredity and environment while studying human behaviour?

Ans: Nature and nurture both play an important role in a child’s development. We inherit some features, while others are what we develop over time as a result of interacting with our environment. In short, heredity and environment interplay determine our physical and psychological makeup. Psychologists usually undertake studies on twins (identical and fraternal twins) to understand the role of heredity and environment.

4. Discuss the functioning of human behaviour.

Ans: The behaviour of an individual does not occur in isolation; it is determined by both genetics and environment. The term environment encompasses physical, psychological, and socio-cultural environments. We have our individual food preferences, based on our taste, choice, mood, and availability in time and situation, i.e. it is guided by our psychological, socio-cultural upbringing and the ecological environment that we are part of.

5. Elaborate the role of endocrine system in human behaviour.

Ans: Signals from the nervous system and hormonal release from the endocrine system are the internal sources for the behaviour, undertaken as action or reaction. For the overall functioning of the body, the regulated release of various hormones is important. They are responsible for the optimal functioning of various parts of the body, including the nervous system. They also control our reactions to the external environment.

6. What are the major social agents that guide human behaviour?

Ans: The major social agents that guide human behaviour are parents, siblings, peers, school, and media.

i. Parents: Parents are the first social contact that a child experiences. A child’s behaviour is shaped by the regular parental interactions like talking, eating, guiding, rewarding certain behaviors and punishing other behaviours, the level of control exerted, etc. The way parents behave with each other, their interaction with the rest of the family members, various social groups, etc. also affects the behaviour of the child.
ii. Siblings: The influence that siblings have on each other cannot be overlooked. They are the ones who spend a lot of time together. Living with a brother or sister teaches a child various things like adjustment, sharing, respecting the other person’s space, and dealing with conflicts. If a child shares a good relationship with his or her sibling, it helps in better growth of the child.
iii. School: The next social system a child comes in contact with is school. This is a child’s first exposure to a structured social system. It helps children learn rules and regulations, gives them a platform to develop self-initiative and helps in developing relations beyond parents in the form of teachers, peers, friends, etc. So, children start socialising with others who are different from family members.
iv. Peers: Within the school system and beyond, as the child grows, peers become a major influencing group. Being of the same age, peers become the most relatable social agents. They help a child inculcate the habits of sharing, caring, mutual understanding, trust, etc. Children also learn to assert their viewpoint through their interaction with peers.
v. Media: As discussed earlier, culture is influenced by changing times. Media, which is a scientific development of the virtual world, has been identified as a significant contributing agent of socialisation. The exposure to harmonious, violent, and funny content on television influences a growing child through imitation. The media (virtual world) has enabled children to grab information with the touch of a button. The information hence sought should be guided and monitored to prevent children from developing undesirable behaviour through this social agent.

7. Explain different levels of Bronfenbrenner’s model that focus on interconnection between the individual and the environment.

Ans:

i. Microsystem- The environment that a child comes in immediate contact with and lives in is the microsystem, like the family, school and peers. It also encompasses the various ways in which the parents, siblings, teachers, friends etc., interact with the child. The more supportive these interactive patterns are, the better is the development of the child.
ii. Mesosystem- This level talks about the relationship between the various components of the microsystem, i.e. how do the parents interact with the teachers, what connection is there between the parents and peers of the individual, etc. Such experiences affect the kind of relationship the individual has with others. For example, during parent-teacher meetings, if parents use supportive and positive words for the child instead of complaining about him/her, the child’s confidence boosts and s/he learns to talk positively about others in a social setting.
iii. Exosystem- The environmental factors that have an indirect effect on the development of individuals, like the workplace of parents. The child may not be interacting with these factors, but they do impact the developmental process of the child. For example, if the father doesn’t get his idea approved in the office meeting, he might show his anger at home, which will, in turn, affect the child negatively.
iv. Macrosystem- It comprises the culture in which an individual is brought up. The values, ideas and beliefs all come under this system. Culture is a phenomenon which differs from society to society. For example, children brought up in Western culture will be more individualistic than children from the collectivistic Eastern cultures of the world.
v. Chronosystem- It includes the changes in the environment of an individual that occur over time. It includes instances like the transfer of either of the parents to a new place, which might result in meeting new people. Another example could be the birth of a sibling. When a younger sibling is born, the entire pattern of interaction that the child had earlier changes. If in such situations, the child is neglected due to a change in the circumstances, the child might develop behaviours such as an inferiority complex, which are not good for his/her development.

8. Differentiate between CNS, PNS, and ANS.

Ans: Central Nervous System (CNS) and b. The Peripheral Nervous System (PNS) is the main division of the nervous system. The autonomic nervous system is a subdivision of the PNS.

Central Nervous System: It is the brain that continues as the spinal cord in the form of a long stalk. The brain integrates the inputs from the sensory organs, analyses them (cognitive appraisal) and carries out the motor activities as per the requirement. However, the brain would be useless without the functioning of the spinal cord.
PNS consists of the nerve fibres or axons which:
- 1) carry nerve inputs from the sensory receptors to the body, inward to the CNS;
- 2) carry nerve impulses for the movement of muscles and the excitation of certain glands outward from the CNS.
Autonomic Nervous System (ANS) is part of the peripheral nervous system. All the involuntary muscles, organs and glands are controlled by the Autonomic Nervous System (ANS). It is further categorised as a Sympathetic and Parasympathetic Nervous System.

9. Describe major functions of the brain.

Ans: The main functions of the brain are Survival, Motivation and emotion, and, Higher mental processing.

Survival Function: The brain stem covers the medulla, pons, cerebellum, and the reticular activating system (popularly known as the midbrain). Pons facilitate the passing of sensory and motor information, and they are responsible for sleep-arousal, muscle tone and cardiac reflexes. The cerebellum transmits the information to the higher parts of the brain and controls the movements. Reticular Activating System activates/arouses the central cortex and is involved in sleep-arousal, regulation of muscle tone and cardiac reflexes.
Motivation & Emotion: Motivational behaviours like eating and aggression are controlled by a small structure that lies in the deep layers of the brain i.e., the hypothalamus.
Higher Mental Processes: Abilities like reasoning, planning, remembering, and imagining are taken care of by cerebral cortex.

10. Cerebral Cortex covers the entire surface of the brain. How do its different lobes function in transmitting and receiving information?

Ans: The cerebral cortex covers the entire surface of the brain. Based on functionality, the cerebral cortex is divided into four lobes: Frontal, Parietal, Temporal, and Occipital.

The frontal lobe lies in front of the central fissure, and is responsible for cognitive functioning, like attention, thinking, memory, learning and reasoning, and is also responsible for inhibitory effects on autonomic and emotional responses.
Parietal lobe is placed behind the central fissure. It is responsible for processing information from skin and internal body receptors for touch, temperature and body positioning.
The temporal lobe is located behind the temples. The main function this lobe is responsible for is hearing. It is also responsible for the memory of symbolic sounds, the understanding of speech and written language.
The occipital lobe is placed at the base of the cortex, towards the back of the brain. It is responsible for the visual information from the eyes, in the form of visual impulses, and memory for visual stimuli.