Chapter 1: Overview of Genetics

How many biological disciplines does genetics encompass?

Four

What are the four biological disciplines genetics encompasses?

Molecular, Cellular, Organismal, and Population

Into how many areas is genetics traditionally divided?

3

What are the three traditional areas of genetics?

Classical (Transmission) Genetics, Molecular Genetics, and Population Genetics

What is another name for Classical Genetics?

Transmission Genetics

What does Classical (Transmission) Genetics examine?

How traits are passed from one generation to the next

Who provided the conceptual framework for classical genetics?

Gregor Mendel

When did Gregor Mendel provide the framework for classical genetics?

In the 1860s

How do genetic determinants pass from parent to offspring according to Mendel? (How did Mendel think traits are inherited from parents)

According to Gregor Mendel, genetic determinants pass from parent to offspring as discrete units (Traits are passed down as separate little instructions (genes) from each parent

What is the basic experimental approach in classical genetics?

The genetic cross

What happens in a genetic cross?

Two selected individuals are mated

Over what are traits analyzed in classical genetics?

Several generations

What type of analysis is often used in classical genetics?

Quantitative analysis

What does molecular genetics deal with?

The molecular features of DNA and how these underlie gene expression

What aspects of genes are studied in molecular genetics?

A gene’s features, organization, and function

What molecules are analyzed in molecular genetics?

DNA, RNA, and proteins

What do molecular geneticists typically employ for research?

Genetic approaches

What kind of genes do molecular geneticists study?

Mutant genes that have an abnormal function

What does population genetics deal with?

The genetic variation of populations and how that variation is related to the environment

What do population geneticists develop?

Mathematical theories

What do population geneticists try to explain?

The prevalence of certain alleles within populations

When was the Human Genome Project formally launched?

1990

What was the goal of the Human Genome Project?

To decode the human genome

What is the genome?

All of the DNA found within all of our chromosomes

Which organizations coordinated the Human Genome Project?

The National Institutes of Health (NIH) and the Department of Energy (DOE)

Who carried out the Human Genome Project?

Scientists from around the world

What does NIH stand for?

National Institutes of Health

What does DOE stand for?

Department of Energy

When was the completed sequence of the human genome published?

2003

About how many nucleotides are in the human genome?

Nearly 3 billion nucleotides

What was the accuracy of the completed human genome sequence?

Greater than 99.99%

What does the study of the human genome provide?

Fundamental molecular details about ourselves

What can studying the human genome tell us about genes?

How many genes we have

What can studying the human genome tell us about cells?

How cells develop into complex tissue

What can studying the human genome tell us about disease?

How defective genes cause disease

What has knowledge from the Human Genome Project improved?

Diagnosis, treatment, and prevention of disease

What chromosome is shown on the slide?

Chromosome 4

What does the slide demonstrate about chromosome 4?

Genes on chromosome 4 are associated with diseases when mutant

What disease on chromosome 4 is associated with Huntington disease?

Huntington disease

What syndrome on chromosome 4 is listed on the slide?

Wolf-Hirschhorn syndrome

What metabolic disorder on chromosome 4 is shown?

PKU due to dihydropteridine reductase deficiency

What connective tissue disorder is listed on chromosome 4?

Dentinogenesis imperfecta-1

What kidney disorder is listed on chromosome 4?

Polycystic kidney disease, adult, type II

What immune disorder is listed on chromosome 4?

Severe combined immunodeficiency due to IL2 deficiency

What muscular disorder is listed on chromosome 4?

Facioscapulohumeral muscular dystrophy

What cancer-related condition is listed on chromosome 4?

Hepatocellular carcinoma

What are the four DNA bases?

A, T, G, and C

How many chromosomes do humans have?

46 chromosomes

How many chromosome pairs do humans have?

23 pairs

About how many genes do humans have?

Approximately 20,000–25,000 genes

About how many DNA base pairs are in humans?

About 3 billion base pairs.

What is a gene?

A section of DNA that codes for a product, usually a protein.

What does DNA get converted into before proteins are made?

mRNA

What are proteins made of?

Amino acids.

What year was the draft human genome published?

2001.

What year was the human genome sequence completed?

2003

What is the flow of genetic information?

DNA → mRNA → Protein

What organism had about 3.2 billion bases sequenced?

Homo sapiens

What organism had about 3.48 billion bases sequenced?

Mus musculus (mouse)

What molecule is considered the molecule of life?

DNA

What do genes help produce?

Proteins

What are proteins composed of?

Amino acids.

Approximately how much DNA is in a human cell?

About 2 meters of DNA.

What does mRNA stand for?

Messenger RNA.

What project aimed to decode all human DNA?

The Human Genome Project.

make sure you can draw this

What are the two steps of gene expression?

Transcription and translation

What happens during transcription?

Genetic information in DNA is copied into RNA.

What happens during translation?

The RNA sequence is converted into the amino acid sequence of a protein.

What molecule carries genetic information from DNA during transcription?

RNA (messenger RNA or mRNA).

What does gene expression mean?

The process by which information in DNA is used to make proteins.

What is produced directly from DNA during transcription?

RNA.

What is produced during translation?

A protein.

What is the correct order of gene expression?

DNA → RNA → Protein.

What does mRNA stand for?

Messenger RNA.

What is translation converting RNA into?

Amino acids/proteins.

What part of DNA is used during gene expression?

A gene.

What determines an organism’s traits according to the diagram?

The functioning of proteins within cells.

What is a protein made of?

Amino acids.

What type of acid is RNA?

Ribonucleic acid.

During which step is DNA copied into RNA?

Transcription.

During which step is RNA used to make proteins?

Translation.

What molecule comes between DNA and protein?

RNA.

What is the final product of gene expression?

A protein.

What carries the instructions from DNA to make proteins?

mRNA.

What biological process accesses information within DNA?

Gene expression

Draw this diagram

Can you think of a situation that does not follow the Central Dogma?

The central dogma is usually:

DNA → RNA → Protein

A situation that does NOT follow this is:

RNA → DNA

This is called reverse transcription.

Example:

Retroviruses like HIV use reverse transcriptase to turn RNA into DNA.

That’s probably the answer your professor wants.

What is a trait?

Any characteristic that an organism displays.

What are morphological traits?

Traits that affect the appearance of an organism.

What is an example of a morphological trait?

The color of a flower.

What are physiological traits?

Traits that affect the function of an organism.

What is an example of a physiological trait?

The ability to metabolize a sugar.

What are behavioral traits?

Traits that affect how an organism responds to the environment.

What is an example of a behavioral trait?

Mating calls of bird species.

Which type of trait affects appearance?

Morphological traits.

Which type of trait affects function?

Physiological traits.

Which type of trait affects responses to the environment?

Behavioral traits.

What type of trait is flower color?

Morphological.

What type of trait is the ability to metabolize sugar?

Physiological.