An increase in the size ofbodily parts or of theorganism as a whole. Itsignifies quantitative changes.
The orderly and sequentialchanges that occur with thepassage of time as an organismmoves from conception to death.Also referred to as gradual growthwhich indicates changes incharacter.
Process whereindevelopment in theindividual is due to bodilychanges determined byheredity.
Refers to a person’s inheritedcharacteristics, determinedby genetics.
Refers to a person’sexperiences in theenvironment.
Heredity Refers to the sum total of characteristicsbiologically transmitted through parents tooffspring and direct determining physicalconstitution and traits. It is nature’s way ofpassing on to children the actual and potentialcharacteristics of parents.
Two Types of Cells of Human Being•Body or Somatic Cells•Germ or Reproductive Cells Heredity is concerned with germ cells. Each of these cells has a nucleus which contains set of 46 chromosomes arranged in 23 pairs.
-Are the physical vehicles that contain the estimatedquarter of a million genes that each human beingpossesses.Genes- Are large molecules of deoxyribunucleic acid (DNA)- Are the actual hereditary units that combine andact to determine the individuals unique physicalstructure.
In the nucleus of the zygote ,the hereditary materials of boththe mother and father combined
The 46 chromosomes contain the individual’sgenotype, the full set of genes inherited from bothparents. How the individual actually looks and actsis his or her phenotype.Defective genes produce defective characteristicsand normal genes, normal characteristics underthe average normal environmental conditions.General Rule:The normal gene is dominant and the defectivegene, recessive.
Most common chromosomal birth defectwhich is often referred to as mongolism.Usually caused by the presence of anextra chromosome.It is characterized by severe mentalretardation, skeletal deformities andabnormally—wide set eyes.
This results in females having asingle X chromosome, instead of thenormal XX.This disorder usually involves failure todevelop sexual characteristics; the individualthat has the female genetalia but lacksovaries, hence, cannot become pregnant.
Although usually of normalintelligence, the individual shows specificcognitive defects which is called VISUALAGNOSIA - inability to discriminate orrecognize the form of objects.also known as "Gonadal dysgenaesis"
This occurs in perhaps one in every 400males.The male is characterized to have an extraX chromosome, hence a combination of XXY.The individual is physically a male, with penisand testicles, but marked femininecharacteristics. He has feminized breastdevelopment, and small testes that do notproduce sperm.
This is another sex chromosome abnormalityin males which results in abnormality large,aggressive males who may become aggressivecriminals.
1. Growth and development is a continuous process, but it does not proceed at a uniform rate.2. Growth and development may be accelerated or retarded.3. The process of growth and development are influenced by heredity and environment.4. Growth is unique. Some functions that result from growth are unique to the species like crawling, standing and walking. These are called phylogenetic functions. While functions that are unique to the individual are called ontogenetic functions, like for example, skating and bicycling which are acquired through practice and not because one is a member of the species.
6. Growth is sequential. Human beings tend to develop in an orderly and predictable sequence. The infant gradually becomes mobile by lifting first his head, then his chest, and then his abdomen. He sits, crawls, stands alone and then walks in that order. The sequence is orderly, but the timing may be varied.7. Development is a product of maturation and learning.8. The various aspects of development are integrated. For example, gains in one phase of growth depends on gains in other aspects, like emotional growth depending on social growth and cognitive development depending on physical growth.
1.Principle of DirectionalityDevelopment governed by maturation has aclear directionality. In the case of fetaldevelopment, there are two directions.Development proceeds from the headdownward (cephalocaudal) and from thetrunk outward (proximodistal).
2.Principle of functionalasymmetry This refers to the tendency ofhuman to develop asymmetrically.Example: handedness.
3. Principle of self-regulatingfluctuation Development does not proceed atthe same even pace along all frontssimultaneously. For example: the childdoes not usually begin talkingextensively until he has learned towalk.
1. Heredity is determined at the moment of conception.2. Variations occur for within the species there are differences. No two individuals are exactly alike.3. Inheritance is not merely from the father and the mother, but also from the two lines of ancestry of both families.
5. All hereditary qualities are not apparentat birth.6. Heredity involves a general capacity todo certain things rather than a specificability, that is, what is inherited is the totalof potentialities which can manifestthemselves only in the course ofdevelopment under suitable conditions.7. Acquired characteristics are notinherited.