Heredity and Environment: NBSE Class 12 Education answers, notes
Get summaries, questions, answers, solutions, extra MCQs, PDF for Heredity and Environment: NBSE Class 12 Education, which is part of the syllabus for students studying under NBSE (Nagaland Board). These solutions, however, should only be treated as references and can be modified/changed.
Summary
Heredity is the process of passing traits from parents to their children. The word comes from a Latin term meaning inheritance. This process begins at conception, when a sperm cell from the father and an ovum, or egg cell, from the mother join. From this moment, a person’s inherited traits are set. However, the environment also begins to influence the person from this early stage. Both heredity and environment work together to shape an individual’s personality and qualities.
The biological basis of heredity involves chromosomes and genes. In humans, both the sperm and the ovum contain 23 chromosomes. When they unite, the new organism has 46 chromosomes in total. These chromosomes hold tiny particles called genes, which carry the instructions for traits like height, eye colour, and even sex. Sex is determined by specific chromosomes known as X and Y. A female child is formed from two X chromosomes, while a male child is formed from an X and a Y chromosome. The unique combination of genes from both parents is a matter of chance, which is why every person is different.
There are several types of heredity. Biological heredity covers the physical traits we inherit. Mental heredity includes inborn instincts and possibly intelligence. Social heredity is different because it is not inherited at birth. It consists of the culture, laws, language, and traditions that a person learns from their society. There are also general patterns, or laws, of heredity. The law of “Like Begets Like” observes that children often resemble their parents. A common phrase for this is “a chip off the old block”, which means a child is very similar to their parent. The Law of Variation explains why children are also different from their parents due to new gene combinations. The Law of Regression states that extreme traits in parents, such as being exceptionally tall, tend to be less extreme in their children, moving closer to the average.
The environment is everything that surrounds and influences a person from conception until death. It includes the prenatal environment inside the mother’s womb and the postnatal world of family, school, food, and community. A positive and stimulating environment helps a person develop well. The environment can be physical, like the climate and geography. It can also be social, involving the people we interact with, and cultural, which includes the beliefs and customs of our community. Both heredity and environment are needed for a person’s development. Heredity provides a person’s potential, while the environment offers the opportunities to develop that potential. For teachers, understanding this relationship helps them recognize the individual needs of students and create a good learning atmosphere for all.
Textual
Very Short Answer Questions
1. What is the etymological meaning of heredity?
Answer: The word ‘heredity’ is derived from the Latin word ‘hereditas’, which means capital that a child gets from his/her parents as inheritance. Based on this etymological meaning, heredity is the transmission of genetic characters from one generation to the next.
2. What is the significance of heredity and environment in a child’s development?
Answer: Heredity and environment have equal significance in a child’s development and play an important role in the development of the personality and other qualities of an individual. Just as food and water are equally important for a person, both heredity and environment are compulsory. A child is the product of both heredity and environment.
3. What is social environment?
Answer: The social environment includes the social associations that a child has from the very beginning. It also includes the cultural atmosphere of the society with its ingredients such as religion, folklore, literature, art, music, social conventions, and political organisation. Every individual inherits cultural traits from the social environment.
4. What is mental heredity?
Answer: Mental heredity refers to the inheritance of mental characteristics, in addition to physical ones. Every child at birth instinctively sucks, breathes, laughs, cries, and moves the limbs; all these instincts are inherited. Intelligence also appears to be inherited, as the intellectual ability of children often resembles that of their parents. Some tendencies to commit crime are also reported to be inherited, as shown by case studies.
5. What is the Law of Variation?
Answer: The Law of Variation explains the exceptions to the rule that ‘like begets like’. According to this law, a child is not fully similar to the parents but is somewhat different from them. This difference is due to variance in gene combination during fertilisation and birth. For instance, short parents may have tall children if the combined genes are dominant for tall characteristics.
Short Answer Questions
1. Define heredity.
Answer: The word heredity is derived from the Latin word ‘hereditas’ which means capital which a child gets from his/her parents as inheritance. Based on this etymological meaning, heredity is the transmission of genetic characters from one generation to the next. This process starts from the union of sperm and ovum during conception.
Heredity consists of all the structures, physical characteristics, functions or capacities derived from parents, other ancestors or species. It is the sum total of inborn individual traits and covers all the factors that are present in the individual at the time of conception.
2. What is heredity in psychology?
Answer: In psychology, heredity refers to the transmission of certain psychological characteristics from parents to their offspring. A child carries with itself several physiological and psychological peculiarities that are present in the parents.
Besides physical characteristics, many mental characteristics are inherited. These include instincts, as every child at birth instinctively sucks, breathes, laughs, cries, and moves its limbs. Intelligence also seems to be inherited, as in many cases, the intellectual calibre of children resembles that of their parents. Some tendencies to commit crime are also reported to be inherited.
3. What is social heredity?
Answer: Social heredity includes social etiquettes, laws, customs and traditions, mother tongue, a system of philosophy, religious books, pictures, works of art, and architectural monuments. It is the sum total of the past achievements of more than one generation and is a form of an educational environment that affects more than a single generation. We are not born with social heredity; it is acquired.
The term social heredity is significant as it describes the act of transmission of social and cultural patterns to each new generation. Education is a form of transmission of culture or of social heredity.
4. What is an environment? Give two definitions in justification of your answer.
Answer: The word environment means the surroundings of a child, including his/her interaction with family, neighbourhood, school, the nutrition the child receives, and more. It consists of the sum total of the stimulation that an individual receives from conception until death. Anything that surrounds an individual can be covered by the term environment. It includes both pre-natal and post-natal environments, such as food items, school, family, and locality.
Two definitions that justify this are:
- Environment is an external force which influences us.
- Environment covers all the outside factors that have acted on the individual since he began life.
Long Answer Questions
1. How does heredity and environment affect development?
Answer: Heredity and environment both play an important role in the development of an individual’s personality and other qualities. Each individual has a different pattern of behaviour and personality, and this difference is seen due to the influence of both heredity and environment. No person can be born without heredity, and genes cannot develop without a proper environment. An individual’s heredity is present from the moment of conception, and environmental conditions also start influencing them from this very stage. Each trait and response of an individual depends on their heredity and environment.
Development is considered the product of heredity and environment. According to Woodworth, the relationship between heredity and environment is more like the product of multiplication than of addition. According to T.P. Nunn, the human organism, body, and mind is a centre of creative energy that uses endowments and environment as its working material. According to Ruch (1970), this relationship is expressed in the formula DL = H x E x T, where DL is Development Level, H is Heredity, E is Environment, and T is Time.
Heredity has its influence on physiological traits, but the environment is also the arbiter of our development. Heredity is of no avail if the environment is not there to show it off. As David Abrahamson wrote, “heredity determines what a person can do, and environment what he will do”. Similarly, Landis and Landis state, “Heredity gives us the capacities to be developed but opportunity for the development of these capacities must come from the environment. Heredity gives us our working capital; environment gives us opportunity to invest it. Heredity explains man the animal, environment man the human being”.
Ultimately, human development is the product of both heredity and environment, and each trait requires both for its development.
2. How does heredity affect personality?
Answer: Heredity plays an important role in the development of the personality and other qualities of an individual. The difference in the pattern of behaviour and personality among individuals is seen due to the influence of heredity and environment.
A child carries with itself several physiological and psychological peculiarities that are present in the parents. Heredity determines the structure, complexion, structure of hair, height, facial features, and nasal index of the child. Besides these physical characteristics, many mental characteristics are also inherited. Every child at birth instinctively sucks, breathes, laughs, cries, and moves its limbs; all these instincts are inherited. Intelligence also seems to be inherited, as in a number of cases the intellectual calibre of children resembles that of their parents. Some tendencies to commit crime are also reported to be inherited.
However, in no case of personality development can we properly attribute any characteristic to heredity alone. A given result is always produced by the interaction of gene substance and the environment. As stated by Biesanz and Biesanz, “Personality is the organisation of a person’s attitudes, habits, and traits and arises from the interplay of biological, social, and cultural factors”. Heredity determines what a person can do, while the environment determines what they will do.
3. Explain the nature of heredity.
Answer: The word ‘heredity’ is derived from the Latin word ‘hereditas’, which means capital that a child gets from his/her parents as inheritance. Based on this etymological meaning, heredity is the transmission of genetic characters from one generation to the next. This process starts from the union of sperm and ovum during conception. An individual’s heredity is present from the moment of conception.
Every human being is born as a result of conception, which occurs when two germ cells meet. In the ovary of the female, an ovum or egg cell is present, which contains 23 pairs of chromosomes. In the male’s sperm, there are also numerous germ cells, each with 23 pairs of chromosomes. When a chromosome from a female meets the chromosomes of a male, fertilisation takes place, and life begins. It is this cell or chromosomes which is the process of heredity that an individual gets from his parents.
The child carries several physiological and psychological peculiarities from the parents. Heredity determines traits like structure, complexion, hair structure, height, facial features, and nasal index. Sex is also inherited through the ‘X’ and ‘Y’ chromosomes. An individual’s heredity depends on the genes of his/her parents; whatever one gives to their children is through the genes.
4. Write the mechanism of heredity.
Answer: The mechanism of heredity is explained through the following steps:
- Mating: Mating is the first step for reproduction. The union of male sperm with a female ovum results in a zygote.
- Growth: This step involves the repeated division of the fertilised cell or zygote.
- Chromosomes: Every woman and man receives 23 chromosomes from each parent, making 46 in all.
- Genes: Each chromosome consists of small particles numbering 40 to 100, which are called genes.
- Chance factor: Both the ovum and sperm contain 23 pairs of chromosomes before fertilisation. At the time of conception, the genes in the chromosomes of the sperm pair with the genes of the ovum and determine the potential characteristics and qualities of the offspring.
The result of the union of these genes is called heredity.
5. Explain the controversy between heredity and environment.
Answer: The controversy between heredity and environment, often referred to as “Heredity versus Environment” or “nativism versus empiricism,” concerns the relationship between innateness and environmental influence on development. A nativist view argues that developmental processes are innate and specified by an organism’s genes. An empiricist perspective argues that these processes are acquired through interaction with the environment. Today, developmental psychologists rarely take such extreme positions and instead investigate the relationship between innate and environmental influences.
One area where this debate is prominent is in language acquisition. The empiricist position suggests that language input provides the necessary information for learning the structure of language. From this perspective, language can be acquired via general learning methods. The nativist position, argued by linguist Noam Chomsky, states that the language input is too impoverished for infants to acquire its structure. Chomsky asserts that there is a universal grammar that applies to all human languages and is pre-specified, leading to the idea of a special cognitive module for language learning called the language acquisition device.
The problem of nature versus nurture, however, defies a satisfactory solution. It is futile to ask which of the two factors is more important. According to MacIver, “Every phenomenon of life is the product of both, each is as necessary to the result as the other, neither can ever be eliminated nor can be isolated”. There is an incessant interaction between the two, and they are inseparable.
The conclusion is that the question “which is more important, heredity or environment?” wrongly assumes they are opposed. All the qualities of life are in the heredity, and all the evocations of qualities depend on the environment. Heredity provides the potentiality, and the environment offers a chance to bring it out. The controversy should be concluded by accepting the truth that heredity and environment are the two ultimate determinants of every living being, are of coequal importance, and that none is more potent than the other.
6. Write the educational implications of heredity and environment for students.
Answer: The knowledge of heredity and environment has a great influence on human development. Since the developmental pattern of children is determined by both, the educational pattern, methods, and learning environment should be made by the teacher accordingly. The knowledge of heredity and environment helps the teacher in various ways:
- Knowledge of heredity and environment helps the teacher to know the varying needs and abilities of the children.
- It helps to provide proper guidance to his children in the field of educational, vocational, and personal fields.
- It helps the teacher to classify the students as gifted, normal or slow learner and arrange different types of education for them.
- It helps the teacher to provide a better learning environment in the school.
- It helps the teacher to know the principle of individual differences and arrange the educational experience accordingly.
- It helps the teacher to study the behaviour of the children under different situations.
- It helps the teacher to organise various curricular and co-curricular programmes for the best benefit of the children.
The knowledge of both heredity and environment is of utmost value to teachers, administrators, and educational planners. If this is realised, the system of education will be changed to a great extent.
7. Explain the various types of heredity.
Answer: The various types of heredity are:
- Biological Heredity: This is the observation that cow begets cow, horse begets horse, and human beings beget human beings. Brothers and sisters bear resemblance to their parents in physical characteristics such as size, form, appearance, skin colour, eye colour, and muscle strength. Identical twins resemble each other in every respect at birth, while fraternal twins and siblings resemble each other in many characteristics.
- Mental Heredity: Besides physical characteristics, many mental characteristics are inherited. A child at birth instinctively sucks, breathes, laughs, cries, and moves its limbs. All instincts are inherited. Intelligence also seems to be inherited, as the intellectual calibre of children often resembles that of their parents. Some tendencies to commit crime are also reported to be inherited.
- Social Heredity: This includes social etiquettes, laws, customs and traditions, mother tongue, systems of philosophy, religious books, pictures, works of art, and architectural monuments. It is also known as Social Heritage. Social Heredity is the sum total of the past achievements of more than one generation and is a form of an educational environment. We are not born with Social Heredity.
8. Explain the different types of environment.
Answer: The different types of environment are:
- Physical Environment: This includes all the geographical features that have an effect on the individual, such as food, temperature, climate, and resources for comfortable living. Even in the pre-natal period, the human embryo is surrounded by the physical environment of the womb, where it gets food and nourishment.
- Mental Environment: This refers to the atmosphere that is essential and helpful for a person’s mental development. It includes the intellectual atmosphere at home and school, libraries, recreation rooms, and laboratories. A child learns new experiences unconsciously in the mental environment.
- Social Environment: This includes the social associations a child has from the very beginning. It also includes the cultural atmosphere of society with its ingredients like religion, folklore, literature, art, music, social conventions, and political organisation. Every individual inherits cultural traits from the social environment. The term ‘social heredity’ is significant as it describes the transmission of social and cultural patterns to each new generation.
- Cultural Environment: This is a set of beliefs, practices, customs, and behaviours common to people living within a certain population. Cultural environments shape how a person develops, influencing ideologies and personalities. Religious beliefs are an important building block of a specific cultural environment.
9. Explain the laws of heredity.
Answer: The laws of heredity are explained as follows:
- Like Begets Like: This law is based on the common observation that children are like their parents. A common saying that reflects this is, ‘A youth is a chip of the old block’. A child takes after his parents in size, colour, dullness, brightness, etc. Biologists explain this by the continuity of the germ plasm. However, this theory has been criticised because many exceptions occur, such as children of bright parents not always being bright, and it ignores the effect of the environment.
- Law of Variation: This law explains the exceptions to the “Like Begets Like” rule. Variations occur during fertilisation and birth. In humans, there are 16,777,216 different possible combinations of chromosomes, making each human unique. The process of MEIOSIS explains how different gene combinations lead to different types of children from the same parents. According to this law, a child is not fully similar to the parents but somewhat different due to variance in gene combination. For instance, short parents may have tall children if the genes for tall characteristics are dominant.
- Law of Regression: This law states that “in successive generations variations tend to move towards the average of the species of which they form a part”. This means an offspring will regress towards the normal or average. For example, if a father is a tall man, his son may be tall, but not as tall as his father. This is based on the statistical law of ‘Normal Probability’. Galton explained this by stating that a child’s heredity is determined only 50% by immediate parents, with the rest determined by ancestral parents. This law suggests a tendency for children of very bright parents to be less bright than them, and for children of very inferior parents to be less inferior.
Additional
Extra Questions and Answers
1. What does the Latin word ‘hereditas’ mean?
Answer: The Latin word ‘hereditas’ means capital which a child gets from his/her parents as inheritance.
81. “Every phenomenon of life is the product of both, each is as necessary to the result as the other.” Justify this statement by synthesizing the concepts of heredity and environment.
Answer: The statement by MacIver, “Every phenomenon of life is the product of both, each is as necessary to the result as the other,” is justified by the understanding that heredity and environment are inseparable and interactive forces in development. It is futile to ask which of the two is more important, as they are both compulsory, much like food and water are equally important for a person.
No person can be born without heredity, and genes cannot develop without a proper environment. From the moment of conception, an individual’s heredity is present, and environmental conditions also start influencing him from this very stage. Each trait and response of an individual depends on both his heredity and environment. This relationship is not one of addition but of multiplication. According to Woodworth, the relationship between heredity and environment is more like the product of multiplication than of addition, meaning they work together to produce a result.
Heredity provides the potential, while the environment provides the opportunity for that potential to be realised. As Landis and Landis stated, “Heredity gives us the capacities to be developed but opportunity for the development of these capacities must come from the environment.” Heredity is the “working capital,” and the environment is the “opportunity to invest it.” Similarly, Altenburg’s words, “Each trait requires both heredity and environment for its development,” support this synthesis.
In no case of personality development can we properly attribute any characteristic to heredity or to environment alone. A given result is always produced by the interaction of gene substance and their environment. Therefore, neither can ever be eliminated nor can ever be isolated. They are of coequal importance, and their incessant interaction produces every phenomenon of life.
Extra MCQs: Knowledge-Based
1. The word ‘heredity’ is derived from the Latin word ‘hereditas’, which means:
A. To inherit
B. Capital received as inheritance
C. Genetic transfer
D. Family traits
Answer: B. Capital received as inheritance
26. __________ refuted the possibility of the transmission of acquired traits by experimenting on rats and cutting their tails.
A. McDougall
B. Lamarck
C. Weisman
D. Darwin
Answer: C. Weisman
Extra MCQs: Competency-Based
27. Nativism : Heredity :: Empiricism : __________
A. Genes
B. Environment
C. Instinct
D. Biology
Answer: B. Environment
40. (I) A child instinctively sucks, breathes, and cries at birth.
(II) This is an example of mental heredity.
A. I is the cause of II.
B. I is an example of II.
C. I is a contradiction of II.
D. II is the cause of I.
Answer: B. I is an example of II.
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