DNA is very important Or How it can change the world.

DNA is very important

Or

How it can change the world

Pedigree symbols

What is the phenotype of the offspring of individuals 1 and 2?

1 2

3

5 64

What about 4, 5, and 6?

What do you know about the genotypes of individuals 1 and 2?

1 2

Sometimes, they look like this:

Half-filled circles/ squares represent carriers, or heterozygous genotypes.

Karytopye – picture of all chromosomes

Shows chromosome abnormalities

Down Syndrome

Turner Syndrome

Klinefelter Syndrome

Cri-Du-Chat

Jacobs Syndrome

It’s TEXT TWIST!

Use the following letters to make as many words as you can:

A E L T

Mutations: the good, the bad, and the indifferent

• Point mutations

• Frame-shift mutations

• Not all mutations are bad – some make bacteria ANTI-BIOTIC RESISTANT.

Good for the bacteria, not-so-good for you!

• Some mutations result in no change

Mutations are changes in DNA

• Changes in DNA result in changes in the protein.

• Changes in the protein can introduce new characteristics (blonde hair)

• New traits can be passed to offspring

Mutations can change a population

• If new traits are advantageous, those individuals will have more offspring with the new traits.

• Over long periods of time, these populations can become new species.

• Species are defined as groups that can breed with each other and produce VIABLE offspring.

This is Natural Selection.

New species can develop if…

• Members of a populations are separated from each other (GEOGRAPHIC ISOLATION)

• Members of two populations stop breeding with each other (REPRODUCTIVE ISOLATION)

• Having an abnormal number of chromosomes (POLYPLOIDY)

Divergent Evolution

• One ancestral species leads to 2 new species

Ancestral Green Iguana

Marine Iguana

Land Iguana

Adaptive Radiation

• One ancestral species leads to 3 or more new species

Gradualism or Punctuated Equilibrium?

• Two ideas of how new species develop

Gradualism: lots of small changes in DNA over long periods of time

Punctuated Equilibrium: fewer, larger changes over long periods of time.

Gradualism

Punctuated Equilibrium

10 million years

10 million years

Notice the results of both are the same: CHANGE

A cladogram is like a family tree showing how things have changed.

Everything to the right of this point have Vertebrae

Point where common ancestors diverged

Shows relationships based on specific characteristics

Phylogenetic tree shows relationships between organisms.

A type of Cladogram that shows the relationships

between organisms with a common ancestor

Each “split” represents a common ancestor

Living things are grouped according to similarities

• Kingdom• Phylum• Class• Order• Family• Genus • Species

Largest

Smallest

Binomial Nomenclature: scientific names are Genus and Species

Ex. Iguana iguana

• Homologous structures (homo=same) VS Analogous structures (not the same, but same function)

- bird wings and

bat wings

-bird wings and

insect wings

Living things are grouped according to similarities

• Embryology

Organisms that have

similar embryonic

development are more

closely related

Living things are grouped according to similarities

Dichotomous keys

• Species can be identified using a dichotomous key

• Series of “either / or” questions leading to the identification.

Example:

1. Does the flower have white or yellow petals?

-if yellow, it is a sunflower

-if white, go to question 2

2. Does the flower have a yellow or red center?

-if yellow, it is a daisy

-if red, go to question 3

Dichotomous keys