The Ugly

Flower

Pollinatio

n

Pretty flower worries that she’ll be pollinated by an ugly

flower.

1.1 : Milestones in genetics: Mendel, Watson and Crick, Human Genome Project

1.2 Structures of DNA and RNA 1.3 Gene organization and gene

expression1.4 Basic features of genetic

engineering

1.1 : Milestones in

genetics: Mendel,

Watson and Crick,

Human Genome

ProjectThere are 3 milestones YOU MUST REMEMBER

1.1 Three Great Milestones in Genetics

Gregor

Mendel: The

Rules of

Inheritance

Genes—hereditary

factors responsible for

traits Alleles—different forms of genes

Rules of Inheritance

Alleles of the same gene separate during gamete formationAlleles of different genes are inherited independently

1.1 The First Great Milestone in Genetics

Genes are made of nucleic acids

Nucleic acids are made of building blocks called nucleotides

Nucleotides have three components Sugar molecule (ribose

or deoxyribose) Phosphate molecule Nitrogen-containing

molecule (adenine, guanine, cytosine, thymine, uracil)

RNA is ribonucleic acid DNA is deoxyribonucleic acid

1.1 The Second Great Milestone in Genetics

Nucleotides are linked in a chain through sugar-phosphate interactions DNA molecules are made of two chains of nucleotides wound around each other in a helix Base pairs hold the chains together A pairs with T G pairs with C

1.1 The Second Great Milestone in Genetics

the entirety of an organism's hereditary information. It is encoded either in DNA or, for many types of viruses, in RNA.

The genome includes both the genes and the non-coding sequences of the DNA/RNA

Non coding DNA/RNA? -- Some noncoding DNA is transcribed into functional non-coding RNA molecules (e.g. transfer RNA, ribosomal RNA, and regulatory RNAs. The amount of noncoding DNA varies greatly among species. For example, over 98% of the human genome is noncoding DNA, while only about 2% of a typical bacterial genome is noncoding DNA.

genetics can be studied at the level of an entire population of organisms.

individuals within a population may carry different alleles of a gene.

perhaps they carry different alleles of many genes.

the member of a population vary in their genetic makeup.

Genome—the collection of DNA molecules that is characteristic of an organism Genomics is the analysis of DNA sequences that make up a genome Genomics involves DNA sequencing technology, robotics, and computer science

The Human Genome Project determined the sequence of nucleotides in the DNA of the human genome

1.1 The Third Great Milestone in Genetics

The Characteristics

• Determining the sequence of

chemical base pairs which make

up human DNA

• Identifying and mapping all of

the genes of the human

genome from both a physical and

functional standpoint

• Sequencing DNA and cataloguing

genes of human

• Identifying all three billion

chemical units in the human

genetic instruction set

• Finding the genetic roots of

disease and then developing

treatments The Goals

The phi X 174 (or ΦX174) bacteriophage was the first DNA-based genome to be sequenced

X174 is a virus that has single-stranded DNA as its genetic material. Frederick Sanger sequenced the genome of X174 in 1977

Gregor Mendel postulated the existence

of particular factors—now called genes

—to explain how traits are inherited.

Alleles, the alternate forms of genes,

account for heritable differences among

individuals.

James Watson and Francis Crick

elucidated the structure of DNA, a

macromolecule composed of two

complementary chains of nucleotides.

DNA is the hereditary material of all life

forms except some types of viruses, in

which RNA is the hereditary material.

The Human Genome Project determined

the sequence of nucleotides in the DNA

of the human genome.

Sequencing the DNA of a genome

provides the data to identify and

catalogue all the genes of an organism.

1.2 Structures

of DNA and RNA

1.2 DNA

Small segments of DNA are called genes. Each gene holds the instructions for how to produce a single protein. This can be compared to a recipe for making a food dish. A recipe is a set of instructions for making a single dish.

An organism may have thousands of genes. The set of all genes in an organism is called a genome. A genome can be compared to a cookbook of recipes that makes that organism what it is. Every cell of every living organism has a cookbook.

Information flows from DNA to RNA to

protein.

In all cellular organisms, the genetic

material is DNA.

The genetic material

Must be able to replicate

Must contain information

Must be able to change

Genetics is the process of trait inheritance from parents to offspring, including the molecular structure and function of genes, gene behavior in the context of a cell or organism, gene distribution, and variation and change in populations.

Given that genes are universal to living organisms, genetics can be applied to the study of all living systems, including bacteria, plants, animals, and humans. The observation that living things inherit traits from their parents has been used since prehistoric times to improve crop plants and animals through selective breeding. The modern science of genetics, seeking to understand this process, began with the work of Gregor Mendel in the mid-19th century.

1.3 Gene

Organization

and Gene

Expression

Based on the complementary nature of the two strands of duplex DNA molecules. When the two parental strands are separated, the separated strands can serve as template for the synthesis of new strands.

New strands are assembled by incorporating nucleotides according to base-pairing rules.

At the end of replication, each template strand is paired with a newly synthesized partner strand.

DNA replication is catalyzed by enzymes.

During transcription, an RNA molecule is synthesized from a DNA template.

This messenger RNA (mRNA) molecules contains the information needed to synthesize a polypeptide.

During translation, the triplet codons in the RNA specify the incorporation of particular amino acids into a polypeptide chain.

The flow of information is DNA RNA protein. Some viruses can use RNA as a template for the

synthesis of DNA in reverse transcription. Many genes do not encode polypeptides; their

end-products are RNA molecules.

1.4 Basic

Features of

Genetic

Engineering

What is genetic engineering? Genetic engineering is the process of manually adding new DNA to an organism. The goal is to add one or more new traits that are not already found in that organism. Examples of genetically engineered (transgenic) organisms currently on the market include plants with resistance to some insects, plants that can tolerate herbicides, and crops with modified oil content.

CONCEPT #1: What is DNA? DNA is the recipe for life. DNA is a molecule found in the nucleus of every cell and is made up of 4 subunits represented by the letters A, T, G, and C. The order of these subunits in the DNA strand holds a code of information for the cell. Just like the English alphabet makes up words using 26 letters, the genetic language uses 4 letters to spell out the instructions for how to make the proteins an organism will need to grow and live.

CONCEPT #2: Why are proteins important? Proteins do the work in cells. They can be part of structures (such as cell walls, organelles, etc). They can regulate reactions that take place in the cell. Or they can serve as enzymes, which speed-up reactions. Everything you see in an organism is either made of proteins or the result of a protein action.

CONCEPT #3: How is DNA important in genetic engineering? DNA is a ‘universal language’, meaning the genetic code means the same thing in all organisms. It would be like if all cookbooks around the world were written in a single language that everyone knew. This characteristic is critical to the success of genetic engineering. When a gene for a desirable trait is taken from one organism and inserted into another, it gives the ‘recipient’ organism the ability to express that same trait.

How is genetic engineering done? Genetic engineering, also called transformation, works by physically removing a gene from one organism and inserting it into another, giving it the ability to express the trait encoded by that gene. It is like taking a single recipe out of a cookbook and placing it into another cookbook.