Introduction to Genetics

What is the study of genetics focused on?

What is the term for the type of genes or hereditary material in an organism?

What is the purpose of variations in living organisms?

What is the term for environmental alterations of an organism's phenotype?

What are the two types of characteristics that individuals of the same species may have?

What is the term for the observable features by which we recognize an organism?

What type of variation is characterized by differences in external genitalia and gonads?

What type of variation is exhibited when an individual cannot distinguish between certain colors?

What is the term for the capacity for reproduction, along with the associated features?

What type of variation occurs when a characteristic varies in small amounts between individuals?

What is the cause of variation in sex determination?

What type of variation is characterized by a pattern of reactions to its environment?

Definition of Genetics

The study of genes and how they are transmitted from parents to offspring (Heredity)
Explains one's origin or ancestry, answering "How one becomes what he is like?"

Variations in Living Organisms

Individuals of the same species may have common characteristics (Species characteristics) and individual differences (Individual characteristics)
Variations provide the raw materials for adaptation

Types of Variations

Phenotype

Various observable features by which we recognize the organism

Genotype

Type of genes or hereditary material in the organism

Phenocopies

Environmental alterations of phenotype, e.g. straightening of curly hair

Categories of Variations

Morphological or Structural

Physical traits or gross anatomical features, e.g. shape of face, ears, eyes, hair color

Cellular, Subcellular, and Molecular

Traits related to cell structure and function, e.g. kind of hemoglobin in RBC, glycoproteins on cell membrane

Physiological or Functional

Biochemical and biophysical processes, e.g. ability to absorb glucose, distinguish colors, perform photosynthesis

Behavioral

Combined structural and physiological traits, pattern of reactions to environment, e.g. IQ, mental retardation, tolerance level

Sexual

Capacity for reproduction and associated features, e.g. primary sexual traits (differences in external genitalia and gonads), secondary sexual traits (non-sexual but related to mating and rearing of young)

Continuous and Discontinuous Variation

Continuous Variation

Characteristic varies in small amounts between individuals, e.g. height, weight

Discontinuous Variation

No intermediate forms, e.g. tongue-rolling, sex

Causes of Variation

Genes (Inherited), e.g. sex determination, mental retardation, infant deformities
[Other causes not mentioned in the text]

Learn the basics of genetics, including its definition, etymology, and significance in understanding heredity and variation. Explore how genes are transmitted from parents to offspring and what it reveals about our ancestry.