Lesson Notes By Weeks and Term - Junior Secondary School 2

FIRST TERM

SUBJECT: BASIC SCIENCE

CLASS: JSS 2

REFERENCE

• Precious seed BASIC SCIENCE FOR JUNIOR SECONDARY SCHOOLS BOOK 2

WEEK SIX

TOPIC: HUMAN GROWTH AND DEVELOPMENT I

SUBTOPIC: Growth, Development and Maturity

CONTENT

• Growth

Characteristics features of stages of development

Factors Necessary for Growth

Growth is the permanent increase in size of organism brought about by cell division. 

Development is the change in the features of an organism, which brings about the manifestation of some characteristics of the organism.

Maturity is the stage of a fully-grown and developed organism.

Growth and Development occur together. Growth continues from birth until individuals reach maturity when growth stops, there are two periods of rapid growth. The first period of rapid growth is from birth until about the age of two years. The other period of rapid growth occur between the ages of nine to about sixteen years.

Development takes place when an organism (human beings) is ready or able to perform a particular function such as talking, crawling, walking, eating solid food and reproducing. These have to do with the development of various systems in the body e.g. digestive, skeletal and muscular, reproductive system. Any human being that has grown to maturity and cannot perform any of these functions has not experienced development in such area. The period between the age of nine and sixteen when reproductive system grow to maturity and become developed is called the puberty period. Maturity in growth and development sets in at the age of twenty-one years in man.

A child’s growth and development can be divided into four periods.

Infancy: This is the period from birth to 18 months. It is the most rapid period of physical growth. Intellectual development is also rapid during this time. In the first 12 months, the average infants weigh triples and its body size increases by about half. Pre- school 18 months to 5years, Middle Childhood years: 6 to 12years

Adolescence: 12 to 18years. This is a stage in which an individual is neither a child nor an adult. The individual grapples with moral issues and attempts to discover his or her own identity. It is a time of learning independence, It is a time of emotional maturity and of coming to terms with adulthood, Mood changes occur(teenager) , It may be a trying time for teenager.

Adulthood: This begins when the body has grown to its full height and also undergoes the sexual changes that make adolescents physically matured. It’s the stage between 16 and 20.It occurs slightly earlier in female than in males who may still be growing in their early twenties. 

Characteristics/ features of stages of development

1. Major physical growth stages. Birth to 5years old
2. By age 5 through 10. Mental and physical developments are rapid and extremely between ages five and ten.
3. Puberty and adolescence. Puberty is the transition stage from childhood to adolescence while Adolescence covers the second half of the teenage period up to the usually undefined point at which a person is seen to be adult.
4. Adulthood. During adulthood, there is room for learning and improving society related skills such as independence, business acumen and responsibilities. This begins when the body has grown to its full height and also undergoes the sexual changes that make adolescents physically matured. It’s the stage between 16 and 20.It occurs slightly earlier in female than in males who may still be growing in their early twenties.

EVALAUTION

1. Define  (a)    Growth    (b)    Development     (c)    Maturity
2. What are the age intervals of the first and second rapid growth and development?

Factors Necessary for Growth

The following factors are necessary for human growth.

FOOD: The major factor necessary for growth is food. Food is required for energy; repair of worn out cells, & production of new cell for growth.

HEREDITY: Growth in man can be affected by the genetic makeup of parents. If the gene of one of the parent carries trait (characteristic) of tallness or being short, by heredity the children, some if not all, would be tall or short.

GLANDS: Glands are special organs in the body for secretion of hormones.

Two of the most important glands for growth are: (i) Pituitary gland (ii) Thyroid gland

The pituitary gland is situated in the head below the brain. It produces growth-stimulating hormone, which determines how tall an individual can be. If in excess it leads to giantism and if in shortage, it leads to dwarfism. The thyroid gland is situated in the neck and it produces growth hormone called Thyroxin. 

The deficiency or reduction shows down growth and leads to conduction called Cretinism. This is a condition of short arms and legs as compared to other parts of the body. 

DISEASE: - Diseases retard growth as it affects the ability to eat well, and the body will be lacking the essential nutrients for growth and development. 

EXERCISE: - Exercise makes muscles big and strong and therefore is better able to resist diseases. Body exercise leads to better growth because 

1. It relaxes and builds up muscles 
2. It enhances cell division 

iii.              It keeps us fit 

1. It does not permit unnecessary accumulation of ingested food. 

REST: - Rest is the act of stopping the body from carrying out physical activities for some time. It helps in body grow as it. 

1. Helps the body to recover from strain 
2. Enables the body to do more work afterwards 

iii.              Enables the body to grow strength faster and to grow properly. 

EVALUATION

1. What are the factors necessary for growth?
2. What is growth?
3. What are the Characteristics features of stages of development?

GENERAL EVALUATION

1. What are the factors necessary for growth?
2. What is growth?
3. What are the Characteristics features of stages of development?
4. Define  (a)    Growth    (b)    Development     (c)    Maturity
5.  What are the age intervals of the first and second rapid growth and development?

READIND ASSIGNMENT

Precious seed BASIC SCIENCE FOR JUNIOR SECONDARY SCHOOLS BOOK 2 page 40-43

WEEKEND ASSIGNMENT

1. The first period of rapid growth is from A.  Ten to seventeen years’ B. birth to about two years C. four to ten years D. seven to nine
2. Development takes place in the body when A. There is increase in size B. the body sizes to grow C. the body is able to perform particular function D. The moves expectedly
3. Maturity sets at the age of A. 30yrs  B. 21yrs C. 25yrs D. 12yrs
4. One of the following is a basic factor affecting growth and development A. Crying 

1. heredity C. bathing D. gene

1. Malfunctioning of thyroid gland results to a condition called A. Cretinism B. giantism C. dwarfism D. Talismanian

THEORY

1. Name five functions that affect growth. 
2. Name two growth glands.
3. What do you understand by cretinism? 

READING ASSIGNMENT

INTEGRATED SCIENCE MADE EASY,BY F.I.K EHINDE pgs 31- 35