Unit One - Genetics

Front 1

Homologous Chromosomes

Back 1

Two genes for one trait

- One from male

- One from female

Identical genes(homozygous) or

Different genes(heterozygous)

- Called alleles

Front 2

Genetics - Genotype

Back 2

Genetic makeup of the trait.

- FF, Ff, ff

- YY, Yy, yy

Front 3

Genetics - Phenotype

Back 3

Outward appearance of the trait.

- Ear lobes (free or attached)

- Seed color (yellow or green)

Front 4

Genetics -Dominant / Recessive

Back 4

Homozygous dominant

- YY (Yellow seeds)

Heterozygous

- Yy (Yellow seeds)

Homozygous recessive

- yy (Green seeds)

Front 5

Genetics - Incomplete dominance (blending)

Back 5

Incomplete dominance (blending)

- Red flowers AA

- Pink flowers Aa

- White flowers aa

Front 6

Genetics - Polygenic inheritance

Back 6

Polygenic inheritance

- More than one gene is involved in the trait

- Human skin color

- Corn seed color at least 4 genes

Front 7

Genetics - Polygenic Example

Y - timing of chlorophyll elimination (Y - early; y - normal)

R - color of carotenoids (R - red; r - yellow)

C - regulation of carotenoid deposition (C - normal; c1, c2 - loweredconcentration)

Back 7

*This leads to a few possible genotypes producing interestingphenotypes:

* Y- rr c1c2 - pale yellow

* Y- rr Cc2 - darker yellow

* yy rr CC - green * Y- R- CC - red

* yy Rr CC - purple

* Y- Rr Cc2 - pale yellow

Front 8

DNA genetic material

Back 8

- Sequence of four nucleotides

- Adenine, cytosine, guanine, and thymine

Front 9

Transcription

Back 9

DNA codes for messenger RNA

Front 10

Translation

Back 10

RNA sequence to sequence of amino acidsin proteins

Front 11

Evolution - Natural Selection

Back 11

- Many variations within a population

- Mutations and meiosis

- More individuals are produced then surviveand reproduce.

- Those individual with favorable variations areselected by the environment and reproduce.

- Over a long period of time the species will fitthe environment.

- End result is many species fitting into manyspecific environments.

Front 12

Natural selectionTypes

Back 12

1) Directional

2) Stabilizing

3) Disruptive

Front 13

Artificial Selection

Back 13

1. Selective breeding

2. Hybrids

3. Polyploidy

4. Recombinant DNA

- Genetically modified foods

Front 14

Selective Breeding

Back 14

Throughout human history

Teosinte to corn

Pistachios to grow in California

Rapeseed - Canola oil

- Low erucic acid and glucosinolates (1974)

Marijuana

- Bushier plants and more psychoactive THC

Front 15

Hybrids

Back 15

Hybridization within a species

- Out-crossing leads to genetic variability

- Inbreeding or self-fertilization leads to lessgenetic variability or identical homozygousindividuals

-Produce a more standard or uniform plants andseeds.

-The offspring of two inbred plant parents

-Produce hybrids that more often have larger seedsor fruit. This is hybrid vigor.

Front 16

Hybrids - Example

Back 16

Hybrids can also occur between two speciesNatural hybridization

Black sage + White sage = Hybrid

Artificial Selection

Grapefruit + Tangerine = Tangelo

Wheat + Rye = Triticale

Plum + apricot = pluot

Front 17

Animal Hybrids - Mule

Back 17

•Sterile

•Donkey 62 chromosomes (31 pairs)

•Horse 64 (32 pairs)

•Mule and hinny each have 63 chromosomes•Many pairs are unevenly matched

•The donkey and horse chromosomes arealmost completely unable to pair up atmeiosis to produce viable sperm and eggs

Front 18

Meiosis

Back 18

- Reductiondivision

- 2N (diploid) to

1N (haploid)

- Increases geneticvariation

Front 19

Polyploidy

Back 19

- Increase in chromosome numbertetraploid, hexaploid or octaploid.

- Mechanism of polyploidy isnon-disjunction.

- Same number or different number ofchromosomes.

Front 20

Non-disjunctioncause of polyploidy

Back 20

Front 21

Polyploidy

Back 21

- Larger plants, fruit, and or seeds

- Occurs naturally by accident

- Occurs through genetic selection ormanipulation

- Drug colchicine

- Cotton, Easter lily - tetraploid

- Wheat - hexaploid

- Strawberry - octaploid

Front 22

Recombinant DNA

Back 22

- Addition of other plant, animal or bacterialgenes (DNA segment) into genome ofanother plant species.

- The use of plasmids or small circular sectionsof DNA.

- Incorporate desired gene into plasmid DNA

- Infect into bacteria DNA.

- Bacteria infect the plant with the plasmid andhopefully insert plasmid and desired DNA intoplant genome.

Front 23

GMF 2006

Back 23

7 million farmers in 18 countries

United States Don’t label foods as GMO

Brazil

India

Canada

China

Paraguay

South Africa

Front 24

Genetically Modified Foods

Back 24

Herbicide (Roundup Ready) resistant

90% Soybeans, 2/3 cotton, ¼ corn, and rapeseed

Insect resistance (Bacillus thuringiensis Bt)

Front 25

GMF - Benefits

Back 25

Enhanced taste and quality of food

Vitamin A in rice

Tomatoes with higher lycopene content

Reduced maturation time

Increased nutrients and yields

Stress tolerance

Improved resistance to disease, pests, andherbicides

Tolerance to cold

Tomatoes and strawberries

Production of vaccines

Front 26

GMF - Controversies

Back 26

Potential human health impacts, including allergens,transfer of antibiotic resistance markers, unknowneffects

Unintended transfer of transgenes through crosspollination

Unknown effects on other organisms

Corn pollen toxic to Monarch butterflies

Loss of flora and fauna biodiversity

Domination of world food production by a fewcompanies

Tampering with nature by mixing genes among species