What is human development?
The scientific study of the changes that occur in people as they age from conception until death.
Research design in which one participant or group of participants is studied over a long period of time. Eg: The Cosby Kids.
Research design in which several different participant age groups are studied at one particular point in time. Eg: 3 classrooms of 3rd graders.
Research design in which participants are first studied via cross-sectional design but are also followed up and assessed longitudinally for a period of no more than 6 years.
What is nature?
Heredity, the influence of our inherited characteristics on our personality, physical growth, intellectual growth, and social interactions.
What is nurture?
The influence of the environment on personality, physical growth, intellectual growth and social interactions.
The basic building blocks of development
The science of inherited traits
Deoxyribonucleic acid (DNA)
Special molecule that contains the genetic material of the organism.
Consists of 2 sugar/phosphate strands
Strands linked together by amines or bases arranged in particular pattern
Section of DNA having the same arrangement of chemical elements (amines). They are located on rod-shaped structures called chromosomes.
Tightly wound strand of genetic material or DNA found in the nucleus of a cell. Humans have 46 chromosomes (23 pairs). 23 chromosomes come from the mother’s egg and the other 23 from the father’s sperm.
Out of the 23 pairs of chromosomes, 22 pairs determine most characteristics. These pairs are called autosomes.
The last pair of chromosomes determines the sex of the person. These two are called the sex chromosomes.
DOMINANT AND RECESSIVE GENES
Referring to a gene that actively controls the expression of a trait.
Referring to a gene that only influences the expression of a trait when paired with an identical gene
When traits are controlled by more than one pair of genes
GENETIC AND CHROMOSOME PROBLEMS
Genetic disorders carried by recessive genes
Sickle cell anemia
FERTILIZATION, THE ZYGOTE, AND TWINNING
The female sex cell, or egg.
The union of the ovum and sperm.
Cell resulting from the uniting of the ovum and sperm. This single cell has 46 chromosomes. The zygote divides by a process call mitosis
Identical twins formed when one zygote splits into two separate masses of cells, each of which develops into a separate embryo. Conjoined twins occurs when cells don’t completely split
Dizygotic twins (fraternal twins):
Occurs when two individual eggs get fertilized by separate sperm, resulting in two zygotes in the uterus at the same time.
What is the germinal period?
The first two weeks after fertilization, during which the zygote moves down to the uterus and begins to implant in the lining. During the germinal period:
Placenta begins to flourish
Umbilical cord develops
Cells begin to differentiate or develop into specialized cells.
Stem cells: cells which stay somewhat immature until needed to produce more cells
THE EMBRYONIC PERIOD
What is the embryonic period
The period of 2-8 weeks after fertilization when major organs and structures of organs develop.
The embryonic period is the most likely time (first 3 months of gestation) for miscarriage or spontaneous abortion.
Times during which certain environmental influences can have an impact on the development of the infant.
Any factor that can cause a birth defect. Eg: Cocaine, alcohol,…