Unit 1

Introduction to Genetics

Georgia Performance Standards for BiologyGenetics

SB2. Students will analyze how biological traits are passed on to\ successive generations.

a. Distinguish between DNA and RNA.b. Explain the role of DNA in storing and transmitting cellular information.c. Using Mendel’s laws, explain the role of meiosis in reproductive variability.d. Describe the relationships between changes in DNA and potential appearance of new traits including:

Alterations during replication. Insertions Deletions Substitutions Mutagenic factors that can alter DNA. High energy radiation (x-rays and ultraviolet) Chemical

e. Compare the advantages of sexual reproduction and asexual reproduction in different situations.f. Examine the use of DNA technology in forensics, medicine, and agriculture.

Chemical basis of life

DNA (Deoxyribonucleic acid)Storage molecule for:

information to produce proteins responsible for the structure (building) of a cell/organism and

information to produce proteins responsible for a cell/organism’s its function (life processes)

What is Genetics?

The science of inheritance (or heredity)

---or---

The study of the transmission of traits from one generation to the next generation

What is a trait ? A distinguishing characteristic or feature

found in or on a living thing. Types of Traits

Acquired InheritedSome traits are a combination of both

Acquired trait

A feature that comes from the environment or an ability that is learned

(You are not born with it!)

Inherited Trait

A feature that is passed down from the parents to their offspring

Humans, as well as many other living things, pass down traits that are needed for the structure (shape) and function of new organisms.

How are traits inherited?

Where is the information that produces traits located in most cells?

In protists, fungi, plants and animals, DNA can be found in the: nucleus : contain nuclear DNA or chromosomal DNA mitochondria : contain mitochondrial DNA

In some protists and plants, DNA can also be found in chloroplasts : contain chloroplast DNA

DNA

nuclearDNA

Nuclear DNA

mtDNA

mtDNA

Chloroplast DNA

Levels of structural and functional organization are controlled by DNA

FATHER OF GENETICSGregor Mendel

• Austrian monk

• In 1850s, carried out experiments using common pea plants.

• Studied seven different traits and the inheritance patterns produced in the offspring from the parent plants that were mated through cross pollination.

• The hereditary mechanisms derived from the results of these experiments can be applied to other complex living organisms, including humans to this day.

The Scientists of the Double Helix

Rosalind Franklin X-ray Diffraction image of DNA

*Francis Crick *James Watson *Maurice Wilkins

*Nobel Prize in Physiology and Medicine Medal

1962