Genetics: the study of hereditary
The Transmission and Expression of Genes in Health & Disease
The study of heredity and the variations of inherited characteristics.
The scientific study of genes.
The study of how traits or conditions are passed from one generation
to another.
The transmission and expression of genes.
The role of genes (individual or groups) in health and disease.
Genetic Disciplines
1. Classical genetics
2. Molecular genetics
3. Population genetics
4. Quantitative genetics
Classical Genetics: Parents & offspring’s
Classical Genetics = Mendelian Genetics = Transmission Genetics
describes how traits are passed on or transmitted from one generation to another (or parents to
offspring).
concentrates on outward appearance.
involves the genetics of sex and reproduction.
involves the study of cells and chromosomes (strands of DNA.
Molecular Genetics (most focused on in medicine)
the study of actual genes (sections of DNA within a chromosome) the physical & chemical
structures of the double helix DNA
The messages or genes hidden in the DNA.
o ex: susceptibility to certain diseases
the study of gene expression
o gene mutations (ex: causes of cancer)
o gene therapy
o genetic engineering
DNA ▶RNA (carries DNA message through process of translation) ▶proteins.
Population Genetics: focuses on studying genetic variation within populations, emphasizing allele
frequencies and the impact of evolutionary processes such as genetic drift and natural selection.
Population of rabbits in a forest. Some rabbits have genes that make them brown, while others
have genes for white fur. Study how these fur color genes spread or change in the rabbit
population over time. Factors like random events, like a forest fire affecting some rabbits, or the
rabbits moving to new areas.
Quantitative Genetics: studies how traits, like height or intelligence, are inherited and influenced by
both genes and the environment. It uses statistical methods to understand the contribution of genetic
factors to the variation of these traits within a population.
A group of siblings in a family. Some may be tall, and some may be short. Quantitative genetics
would
DNA & look at how much of the height differences among the siblings is due to their genes and
Genes:
how much is influenced by other things like nutrition or exercise.
, DNA = deoxyribonucleic acid
molecule that carries genetic information.
linked strands wind around each other resembling a ladder or double helix.
self-replicating material as main constituent of chromosomes.
Genes = fundamental unit of heredity
sections of DNA
specific sections of DNA within a chromosome
sections of DNA made up of sequence of As, Cs, Ts, and Gs *
made up of DNA that come in pairs, one from each parent.
store the code and instructions needed for making protein.
the basic physical & functional units of heredity
“Base pairing rules” (nucleotides pair up as A with T, and C with G)
approximately 20,000 in every cell of the human body
(genes in teeth and bone often used for identification)
Genome= an individual’s full set of chromosomes
Chromosomes & Alleles
Chromosomes = strand of DNA that contain genes
thread‐like strands composed of DNA.
chromosomes are diploids* (2 copies of each chromosome) in humans with
both chromosomes in a pair homologous to one another.
o 23 pairs of chromosomes (or 46 chromosomes) 2n=46
o 22 pairs of autosomal (non‐sex) chromosomes
o 1 pair of sex chromosomes
** Diploid‐ possessing 2 copies of each chromosome
**Haploid‐ possessing one copy of each chromosome (sex cells)
** Homologous chromosomes- two chromosomes in a pair that carry the same but
not identical genes identical in shape and structure and carrying the same genes
diploid organisms inherit one homologous chromosome from each parent.
Chromosome Pairs 1‐23
Chromosome 1 = largest chromosome; 8% of total DNA in our cells
= contains about 249 million DNA building blocks
Chromosome 21 = smallest chromosome; 1.5‐ 2% of total DNA in our cells
= contains about 48 million DNA building blocks
(Chromosome 22‐ previously thought to be the smallest, therefore numbered as 22)
Sex chromosomes‐ last pair of chromosomes
Chromosomal
X and Y ‐ determine biological sexchanges
abnormalities: of an individual
in the
structure
X chromosome has about
or number 1000 genes: Y chromosome < 80
of chromosomes
X chromosome carries more traits (but also more diseases)
Structural changes:
Deletion – portion of chromosome deleted.
The Transmission and Expression of Genes in Health & Disease
The study of heredity and the variations of inherited characteristics.
The scientific study of genes.
The study of how traits or conditions are passed from one generation
to another.
The transmission and expression of genes.
The role of genes (individual or groups) in health and disease.
Genetic Disciplines
1. Classical genetics
2. Molecular genetics
3. Population genetics
4. Quantitative genetics
Classical Genetics: Parents & offspring’s
Classical Genetics = Mendelian Genetics = Transmission Genetics
describes how traits are passed on or transmitted from one generation to another (or parents to
offspring).
concentrates on outward appearance.
involves the genetics of sex and reproduction.
involves the study of cells and chromosomes (strands of DNA.
Molecular Genetics (most focused on in medicine)
the study of actual genes (sections of DNA within a chromosome) the physical & chemical
structures of the double helix DNA
The messages or genes hidden in the DNA.
o ex: susceptibility to certain diseases
the study of gene expression
o gene mutations (ex: causes of cancer)
o gene therapy
o genetic engineering
DNA ▶RNA (carries DNA message through process of translation) ▶proteins.
Population Genetics: focuses on studying genetic variation within populations, emphasizing allele
frequencies and the impact of evolutionary processes such as genetic drift and natural selection.
Population of rabbits in a forest. Some rabbits have genes that make them brown, while others
have genes for white fur. Study how these fur color genes spread or change in the rabbit
population over time. Factors like random events, like a forest fire affecting some rabbits, or the
rabbits moving to new areas.
Quantitative Genetics: studies how traits, like height or intelligence, are inherited and influenced by
both genes and the environment. It uses statistical methods to understand the contribution of genetic
factors to the variation of these traits within a population.
A group of siblings in a family. Some may be tall, and some may be short. Quantitative genetics
would
DNA & look at how much of the height differences among the siblings is due to their genes and
Genes:
how much is influenced by other things like nutrition or exercise.
, DNA = deoxyribonucleic acid
molecule that carries genetic information.
linked strands wind around each other resembling a ladder or double helix.
self-replicating material as main constituent of chromosomes.
Genes = fundamental unit of heredity
sections of DNA
specific sections of DNA within a chromosome
sections of DNA made up of sequence of As, Cs, Ts, and Gs *
made up of DNA that come in pairs, one from each parent.
store the code and instructions needed for making protein.
the basic physical & functional units of heredity
“Base pairing rules” (nucleotides pair up as A with T, and C with G)
approximately 20,000 in every cell of the human body
(genes in teeth and bone often used for identification)
Genome= an individual’s full set of chromosomes
Chromosomes & Alleles
Chromosomes = strand of DNA that contain genes
thread‐like strands composed of DNA.
chromosomes are diploids* (2 copies of each chromosome) in humans with
both chromosomes in a pair homologous to one another.
o 23 pairs of chromosomes (or 46 chromosomes) 2n=46
o 22 pairs of autosomal (non‐sex) chromosomes
o 1 pair of sex chromosomes
** Diploid‐ possessing 2 copies of each chromosome
**Haploid‐ possessing one copy of each chromosome (sex cells)
** Homologous chromosomes- two chromosomes in a pair that carry the same but
not identical genes identical in shape and structure and carrying the same genes
diploid organisms inherit one homologous chromosome from each parent.
Chromosome Pairs 1‐23
Chromosome 1 = largest chromosome; 8% of total DNA in our cells
= contains about 249 million DNA building blocks
Chromosome 21 = smallest chromosome; 1.5‐ 2% of total DNA in our cells
= contains about 48 million DNA building blocks
(Chromosome 22‐ previously thought to be the smallest, therefore numbered as 22)
Sex chromosomes‐ last pair of chromosomes
Chromosomal
X and Y ‐ determine biological sexchanges
abnormalities: of an individual
in the
structure
X chromosome has about
or number 1000 genes: Y chromosome < 80
of chromosomes
X chromosome carries more traits (but also more diseases)
Structural changes:
Deletion – portion of chromosome deleted.
