Genes and Inheritance.

Research in Ecology

The elementsThe elements Meet the elements

Elements combine Elements combine to make Compoundsto make Compounds

H2O

SiO2

C6H12O6

Organic vs. InorganicOrganic vs. Inorganic Organic molecules have a “backbone” of carbon and

hydrogen

Organic molecules are manufactured by living things.

methane ethane benzene

Organic vs. InorganicOrganic vs. Inorganic Inorganic molecules lack the “backbone” of carbon and

hydrogen

Inorganic molecules are the building blocks of organic molecules

water carbon dioxide ammonia

Chemicals reactChemicals react

(combustion of methane)

Methane is the main Methane is the main component of…component of…

(politely known as flatulence)

Chemical HierarchyChemical Hierarchy From smallest unit to largest:

atom molecule

macromolecule (BIG molecule) cell (the smallest LIVING unit)

tissue (cells working together for a common function) organ (tissues working together for a common

function) organ system (organs working together for a

common function) organism (all the organ systems together!)

PolymersPolymers

Protein: The pearls are amino acids

PolymersPolymers

Nucleic Acids: The pearls are nucleotides(A, C, G, or T)

PolymersPolymers

Carbohydrates: The pearls are simple sugars

PolymersPolymers

Lipids (fats): The pearls are fatty acids

Together…Together… Proteins, carbohydrates and lipids make up

the physical structure that is YOU (or any other organism).

How do we do it?How do we do it? Protein can be

STRUCTURAL

How do we do it?How do we do it? Or protein can be

FUNCTIONAL

Helping the cell building things up or break them down.

DNA is the codeDNA is the code

The Genetic CodeThe Genetic Code

Let's watch a movie.

Genes control our Genes control our traitstraits

DNA is composed of a series of units of inheritance called GENES Each gene codes for one PROTEIN Proteins either become part of the body (STRUCTURAL) …or they build other molecules, forming the body

(FUNCTIONAL)

DNA is wound on small protein “spools”

The result is a long, long strand of DNA and protein called a CHROMOSOME

The ChromosomeThe Chromosome Let's see the Magic of the Chromosome

InheritanceInheritance

All animals have All animals have chromosomeschromosomes

gene: a unit of inheritance mutation: any change in a gene locus: the physical location of a gene on the

chromosome

Not locust.

Locus.

All animals and plants All animals and plants have chromosomeshave chromosomes

diploid: having two complete sets of chromosomes (example: a body (somatic) cell)

haploid: having only one complete set of chromosomes (example: sperm or egg)

Genotype to Genotype to PhenotypePhenotype

phenotype: the physical appearance/expression of a given trait in an organism

genotype: the genetic coding of a particular trait in an organism.

Alleles: Alleles: Different Flavors of Different Flavors of

GenesGenes gene: a unit of inheritance. But mutations can give rise

to… alleles: alternate forms of a particular gene.

example: tongue rolling (or not)

dominant

recessive

We all have two alleles We all have two alleles

per gene, but…per gene, but…dominant allele: one which masks the

expression of another at the same locus

recessive allele: one whose expression is masked by another at the same locus.

Everyone has two alleles for each gene One from mom, one from dad.

All animals have All animals have genes on genes on

chromosomeschromosomes homozygous: the two alleles of a gene at a

particular locus are the same in one individual.

heterozygous: the two alleles of a gene at a particular locus are different in one individual.

example: Tongue roller (T) vs. non-roller (t) TT – what will the phenotype be? Tt – what will the phenotype be? tt – what will the phenotype be?

And all animals started And all animals started out as a ZYGOTEout as a ZYGOTE

What we become What we become depends on…depends on…

NATURE The nature and activity of our genes

NURTURE The effect of developmental environment on

our genes

This is true of This is true of all living things.all living things.

Nature vs. Nurture?Nature vs. Nurture?

How much is due to NATURE?

How much is due to NURTURE?

How about doing an EXPERIMENT?