Semester 2, Day 10

Agenda Complete Homework Review for Quiz Turn in Homework Take Quiz Lecture on Genotype, Phenotype, and Natural

Selection Reading/Work Time

Complete Homework 30 minutes Questions

13.1 #1-5 13.2 #1-5 13.3 #1-5 Chapter 13 Assessment #1-15, 17-21

Review for Quiz Define:

Genetic Engineering

Transgenic Organism

Cloning

T-DNA

Know the steps of what Agrobacterium tumefaciens does in nature

(transformation of plant cell)

Three examples of genetic engineering

Where should DNA be inserted in order to affect the ENTIRE organism?

Know the steps of cloning and why the lamb is a clone of the “heart”

sheep.

Turn in Homework

Take Quiz Silence during quiz Eyes on your own paper Put pencil down when finished.

Mendelian Genetics Gregor Mendel: Austrian monk & plant

breeder. Considered the father of genetics due to his findings in breeding pea plants in 1866.

Image Source: commons.wikimedia.org

Mendelian Genetics Inheritance / Heredity: Passing of traits to the next

generation. Genetics: Study of heredity.

Image Source: www.biologie.uni-hamburg.de

Mendelian Genetics Mendel’s Work

Mendel determined there must be 2

forms of a trait in pea plants

alleles!

Same Trait: Color

Different Alleles: Yellow or Green

Also said the trait seen in F1 =

dominant, while masked (hidden)

trait in F1 = recessive.

Dominant Allele: Yellow

Recessive Allele: Green

Dominant allele is labeled with a

capital letter and the recessive

allele is labeled with the

corresponding lower case letter.

Yellow (Dominant): Y

Green (Recessive): y

Generation

Parental (P)(Pure-Breeding)

First FilialGeneration (F1)

Second FilialGeneration (F2)

xYellow Green

All Yellow

6022 Yellow: 2001 Green= 3:1

Mendelian Genetics Genotype: the organism’s allele pair

Zygosity: the similarity of alleles for a trait

Phenotype: observable characteristic of

allele pair

Homozygous Dominant Genotype

Phenotype

Heterozygous Genotype Phenotype

Homozygous Recessive Genotype

Phenotype

ExampleY = yellow pea colory = green pea color

Genotype Zygosity Phenoty

pe

Y Y

Homozygous Dominant Yellow

Y yHeterozygous

Yellow

yy

Homozygous Recessive Green

“Same” “Dominant Alleles”

“Same” “Recessive Alleles”

“Different Alleles”

Y Y = “Dominant” “Dominant” = Yellow “Yellow” “Yellow”

Y y = “Dominant” “Recessive” = Yellow “Yellow” “Green”(Dominant allele masks recessive allele)

y y = “Recessive” “Recessive” = Green “Green” “Green”(No dominant allele to mask recessive)

Evolution Change in a group of organisms over many

generations CANNOT OCCUR IN AN INDIVIDUAL! 5 Mechanisms of Evolution:

Natural Selection Mutations Gene Flow Genetic Drift Nonrandom Mating

Darwin

Father of Natural Selection

Sailed to the Galapagos

Islands

Each island: unique finch

species

Hypothesis: new species

can appear gradually

through small changes over

time

Artificial Selection: pigeon

breeders exaggerate traits

over time.

Evolution Organism: living individual

Need water, food, and a place to live Fitness: ability to survive and reproduce (tall

vs. short)

Natural Selection Species: group of similar organisms capable of

interbreeding (mules are not a species) Individual: single organism in a species Population: many of those individual in same

place

Natural Selection

Some are better

equipped for survival

than others.

Those less equipped

die and don’t

reproduce.

Over time, “good”

traits “build up” until

we have a new

species (can’t breed

with previous

generations)

Basic Principles of Natural Selection 1 – Variation

Individuals differ from one another

2 – Heritability Variations passed

down 3 – Overproduction

More offspring produced than can survive

4 – Reproductive Advantage Some survive and

reproduce more

Genotype vs. Phenotype Genotype: The allele pair Phenotype: What you see

Genotype Zygosity Phenoty

pe

B B Homozygous Dominant Brown

B b Heterozygous Brown

b b Homozygous Recessive Green

Natural Selection worksOn PHENOTYPE, not

on GENOTYPE!!!

Types of Natural Selection 4 Types

Stabilizing Selection Directional Selection Disruptive Selection Sexual Selection

Natural Selection Stabilizing Selection Example: Human Birth

Weight Average is most “fit”, extremes are selected

against

Natural Selection Disruptive Selection Example: Bunnies

Both extremes are most “fit”, average is selected against

Natural Selection Directional Selection Example: Giraffes

One extreme is most “fit”,other extreme is selected against

Natural Selection Sexual Selection Example: Peacocks and

Antelopes Traits that give an organism a better chance at

mating get passed on more to later generations Peacocks: prettier feathers to attract females Antelopes: fiercer fighting to obtain males

Reading/Work Time Cornell Notes:

Pages 392-397 (stop BEFORE “Adaptations: Evidence for Evolution”)

Pages 404-409 (stop BEFORE “The Evolution of Species”)

Questions: 15.1 #1, 5 15.2 #1 Chapter 15 Assessment #2, 6, 9, 11, 16, 18-20