CTET Child Development and Pedagogy Heredity & Environment
What is Heredity?
Heredity is the sum total of the traits gain from through the parents and their ancestors. Those traits are called heredity.
H.A. Peterson - “Heredity may be defined as what one gets from his ancestral stock through his parents.’’
R.S. Wood-worth - “Heredity covers all the factors that were present in the individual when he begins life, not at birth but at the time of conception about nine months before birth.”
Mechanism of Heredity
In the human body, there are certain germ cells, which are constituted out of innumerable genes. These genes are the real transmitters of heredity factors from one generation to the next. The genetic cell has a rod-like structure and is called the chromosome. It looks like a string or thread and it is the gene which passes, “a gene is the carrier of unit character of a heredity factor which is always transmitted as a unit in all or none fashion.” The chromosomes divide and subdivide like amoeba, increasing from two to four, four to eight and so on. These are referred to as the productive cells. The productive cells from the maternal side is called the ovum while the paternal productive cell is termed the sperm. The ovum and the sperm are cells which contain many pairs of genes. To be precise, the ovum and the sperm contain 23 genes each for the transmission of heredity traits. Some scientists hold the view that, instead of 23 genes each, these cells possess 24 cells each. Maternal and paternal genes union leads to the birth of children and it is this union which determines their heredity also.
Heredity Determining Process
- Conception - The status of conception begins when the sperm from the father unites with the ovum from the mother.
- Determination of sex - X and Y chromosomes play the main role in determining the sex of the child. The father possesses both X and Y chromosomes whereas the mother possesses only the X chromosome. When they divide and subdivide, it possesses 23 pair of chromosomes. They are equal in number.
- Twins - Among human beings only some women are found to possess a tendency to give birth to twins or those bom of the same ovum and non-identical. The latter kind is by far the more numerous.Identical twins - One fertilized ovum is divided into two separate parts then two separate fetus grow. Both are same sex.Non Identical twins - Twins when two ovum become mature by two sperms may be of the same sex, as of different sex.
Different Concepts or Principles of Heredity
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Law of continuity of germ plasm -
(i) heredity is determined equally by the mother and the father, i.e. 50% is determined by the mother and 50% by the father,
(ii) the characteristics of grandparents and earlier ancestors exist in fixed quantities as generations progress from one to the next, these ancestral qualities decrease in their influence; for instance, they become successively 1/2, 1/4, 1/8, 1/16,1/32, and so on.
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Law of regression - Regression refers to the discovery of opposite qualities or traits in the offspring. For instance, the birth of talented offspring to momic or subnormal parents is a case of regression.
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Law of Mendal - The famous scientist Greger Jhon Mendel conducted many experiments upon rats and beans to study heredity.
(i) Experiments of beans- Mendel planted together an equal number of large and small beans. He found that the beans grew from these plants were large beans. Subsequently, he planted crossbred variety of beans, which gave rise to crossbred beans only. These beans were also large and pure.
(ii) Experiments on rats- Mendel conducted experiments on rats also, and for this pure pose he placed some white and black rats together. Only black rats were bom in this condition. Subsequently, he placed only crossbred rats together and these gave birth to black as well as white rats.
Law of continuity of germ plasm -
(i) heredity is determined equally by the mother and the father, i.e. 50% is determined by the mother and 50% by the father,
(ii) the characteristics of grandparents and earlier ancestors exist in fixed quantities as generations progress from one to the next, these ancestral qualities decrease in their influence; for instance, they become successively 1/2, 1/4, 1/8, 1/16,1/32, and so on.
Law of regression - Regression refers to the discovery of opposite qualities or traits in the offspring. For instance, the birth of talented offspring to momic or subnormal parents is a case of regression.
Law of Mendal - The famous scientist Greger Jhon Mendel conducted many experiments upon rats and beans to study heredity.
(i) Experiments of beans- Mendel planted together an equal number of large and small beans. He found that the beans grew from these plants were large beans. Subsequently, he planted crossbred variety of beans, which gave rise to crossbred beans only. These beans were also large and pure.
(ii) Experiments on rats- Mendel conducted experiments on rats also, and for this pure pose he placed some white and black rats together. Only black rats were bom in this condition. Subsequently, he placed only crossbred rats together and these gave birth to black as well as white rats.
What Is Environment?
Anne Anastasi has defined the concept of environment thus, “The environment is everything that affects the individual except his genes.”
Types of Environment
- Internal environment - All the conditions come under internal environment which an individual gains in the womb of mother. Cells, chromosomes, genes are the parts of heredity and covered by cytoplasm. It is called intra cellular environment.
- External environment - Conditions which surround the individual is called external environment. C.V. Good defines - every thing outside the organism which stimulates and to which- the organism responds consciously or unconsciously. Earth, sun, moon, climate and nature influence the individual. Life style, rites and rituals, traditions, mores etc influence the social life.
Importance of Heredity and Environment in Education
Both can be beneficial to parents, students, teachers and other related agencies in this manner.
- Education be given according to the physical and individual differences.
- Development of innate powers and capacities can be done by providing good environment
- Instincts may sublimated to desired direction.
- The knowledge of similarity, dissimilarity and regression may lead to proper use of qualities inherited in children.
- The knowledge of child's heredity and environment is helpful in child's education.
- Co-operation from family, school and community be sought for good environment for child’s education.
- Heredity characteristics can be used in adjustment problems.
- Educational, vocational and personal guidance can be given to the students for better education.
- Library, games and other co-curricular activities be provided for all round development.
- Classroom atmosphere should educationally be good.
- Heredity and environment provide opportunities to determine the future of child.
- Self activity and self expression opportunities be provided.
The Teacher’s Role :-The question, why is the knowledge of heredity and environment essential for the teacher, can be answered by pointing out that every child is different. What is the cause of this difference? It is only by learning the cause of these differences that efforts can be made for the comprehensive development of children. It is the cause of the prime task of the teacher to create a good environment. If a teacher ignores or neglects a child because of his poor heredity, he will be committing a blunder. Experiments have clearly established that intelligence quotients can be improved by 10 to 30 points.