10.2 MENDELIAN GENETICS

WHAT YOU WILL LEARN-Law of Segregation-Law of Independent Assortment-How to use a Punnett square

http://www.youtube.com/watch?v=B_PQ8qYtUL0&feature=em-share_video_in_list_user&list=UUWxJwdNjOFOUvKAhsYo41lg

10.2 MENDELIAN GENETICS

MAIN IDEAMendel explained how a dominant allele can mask the presence of a recessive gene.

READING Q’s

DEFINE-What is a true breeding plant?

-same form of trait from generation to generation

READING Q’s

LABEL-Fill in the boxes with the name of each generation of offspring. Draw the peas you would expect to see in the empty pods. Use shading to indicate a green pea.

F-1

F-2

READING Q’s

APPLY-In Mendel’s experiment with green and yellow seeds, what was the dominant trait?

-yellow seeds

READING Q’s

PREDICT-What would be the phenotype of a homozygous, recessive (yy) pea plant?

-green seeds

READING Q’s

APPLY-True-breeding yellow-seeded and green-seeded plants are crossed and produce yellow-seeded offspring. Which of these plants is a hybrid?

-yellow-seeded offspring

READING Q’s

IDENTIFY-What is one purpose of a Punnett square? -tracking genotypes/phenotypes -predicting ratios of cross outcomes

READING Q’s

DEFINE-Circle the genotypes in the small squares that will give a yellow-seed phenotypic ratio in the offspring? What will be the phenotypic ratio in the offspring?

3:1

10.2 READING NOTESMendel is considered the “father of genetics”

Mendel used pea plants because they reproduce by self-fertilization—male gamete combines w/female gameteMendel also used cross-pollination—removed male gamete to combine w/female gamete of a different plant

http://www.youtube.com/watch?v=vIrrtM47WioBill nye greatest discoveries in genetics: 1:25-5:07

10.2 READING NOTESPea plants have 7 traits that are independent of each other—-height stem tall/short-flower location-pod color yellow/green-pod appearance constricted/inflated-seed color yellow/green-seed texture smooth/wrinkled-flower color purple/white

10.2 READING NOTES

GROUP WORK: APPLICATION NOTES

-As a group complete the application note sheet using your knowledge from the reading.

NEW VOCABULARY

DEFINE genetics-study of inheritanceheredity-how traits passed from gen to gensegregation-to “separate”allele-different possible forms of a gene for a particular trait

HISTORY OF GENETICSWrite 4-bulleted facts about Gregor Mendel, “Father of Genetics”-Austrian monk, son of peasant farmer,1840s

-attended University of Vienna—studied math, chemistry, physics, botany, paleontology, plant physiology & statistics

-followed traits in pea plants-discovered how traits were inheritedbegan study of genetics

-determined traits are a combination from both parents

-1866 published math/methods inheritance in pea plants

MENDEL’S EXPERIMENT

ANALYZE Mendel’s experiment with green-seed and yellow-seed pea plants by completing the diagram. generation

_______________ yellow pea (male) green pea (female)

_______________ ALL ___________

_______________ ____ yellow : ____ green

P-parental

F1-first filial

F2-second filial

yellow

3 1

cross fertilization

self fertilization

self fertilization

MENDEL’S EXPERIMENT

DESCRIBE how a plant self-fertilizes:-male & female gametes come from same plant

DESCRIBE cross-fertilization:-remove male part of a flower, transfer to female of diff plant flower

INFER why Mendel used cross-pollination to study inheritance:-create offspring that have traits from both plants

NEW VOCABULARY

-COMPARE/CONTRAST each pair of terms by defining them &/or noting their differences.

dominant trait— observed trait masks

recessive trait

recessive trait—trait observed only if dominant trait is not

present

phenotype— traits an individual displays--red

heterozygous—two different alleles for a

trait--Rr

genotype allele combination--Rr

homozygous—two of the same alleles

for a trait—RR/rr

pure trait— homozygous alleles

hybrid— heterozygous alleles

INHERITANCE OF TRAITS

COMPARE genotypes & phenotypes for pea plants:

genotype homozygous/heterozygous phenotype

________ homozygous yellow seeds

_______ heterozygous ___________

yy _______________ ___________

YY

Yy yellow

homozygous green

LAW OF SEGREGATION

DIAGRAM: Complete the diagram to demonstrate gamete formation & fertilization. grows into plant

gamete

YY yellow pea formation fertilization seed

development

grows into plant

gamete

yy green pea formation

GAMETE FORMATION FERTILIZATION

Y

Y

Y

Y

Y

YYY

F-1 hybridYy = yellow dominant trait

LAW OF SEGREGATION

COMPLETE the Punnett square-fill in missing info:

R r R

r

P

Rr

rr

RR

Rr

LAW OF SEGREGATION

COMPLETE the Punnett square-fill in missing info:

R r R

r

P

Rr

rr

RR

Rr

LAW OF INDEPENDENT ASSORTMENT

DEFINE: law of independent assortment—

-genes for different traits are inherited independently of each other

LAW OF INDEPENDENT ASSORTMENTDEMONSTRATE law of independent assortment by listing the 4 alleles that are produced when a pea plant with the genotype RrYy produces gametes—

R r Y y

RY Ry rY ry

LAW OF INDEPENDENT ASSORTMENT

IDENTIFY the genotypes/phenotypes in Punnett square showing DIHYBRID cross of seed color Yy & texture Rr

YR Yr yR yr YR

Yr

yR

yr

YYRRyellow/round

YYRryellow/round

YyRRyellow/round

YyRryellow/round

YYRryellow/round

YYrryellow/wrinkle

YyRryellow/round

Yyrryellow/wrinkle

YyRR yellow/round

YyRryellow/round

yyRRgreen/round

yyRrgreen/round

YyRryellow/round

Yyrryellow/wrinkle

yyRrgreen/round

yyrrgreen/wrinkle

LAW OF SEGREGATION

COMPLETE -Punnett squares to show height in F1 & F2 generationsT = tall plants t = short plants

F1 generation F2 generationT T T t

t T

t t

100% Tt

Tt Tt

Tt Tt

TT Tt

Tt tt

25% TT / 50% Tt / 25% tt

PROBABILITY

DEFINE: probabilitylikelihood a specific event will occur

PREDICT PROBABILITIES-What is the probability of rolling a 5 on a dice?

1 out of 6 = 1/6-What is the probability of 2 coins landing on heads if you flip 2 coins?

½ X ½ = ¼-What is the probability of rolling a 3 when rolling a die?

1 out of 6 = 1/6-What is the probability of rolling two 3s on two dice?

1/6 X 1/6 = 1/36

PROBABILITY

DEFINE: probabilitylikelihood a specific event will occur

PREDICT PROBABILITIES-What is the probability of one coin landing on heads if you flip a single coin once?

1 out of 2 = ½-What is the probability of 2 coins landing on heads if you flip 2 coins?

½ X ½ = ¼-What is the probability of rolling a 3 when rolling a die?

1 out of 6 = 1/6-What is the probability of rolling two 3s on two dice?

1/6 X 1/6 = 1/36

COIN TOSS PROBABILITY

PRACTICE PROBABILITY—-Use 2 coins to show the probability of the occurrence of

HH / HT / TT

-Mendel’s experiments with pea plants did not get exact 9:3:3:1 ratios, however, the more experiments he conducted the closer the ratios were to the actual.

-You will first flip the coins 10 times to get a ratio-Then you will flip the coins 100 times to see if the ratio is closer to the predicted outcome

INHERITANCE OF TRAITS

CHECK -- 10.2 VOC-__________ is the branch of biology that studies how traits are inherited.-__________ offspring result from parents that have different forms of __________ for certain traits.-Mendel’s ____________________ states that every individual has two alleles of each gene and when gametes are produced, each gamete receives one of these alleles.-Mendel’s ___________________________ state that genes for different traits are inherited independently of each other.

Genetics

Hybrid

alleleslaw of segregations

law of independent assortment

INHERITANCE OF TRAITS

COMPLETE the paragraph—-Mendel was the first person to succeed in predicting how traits are __________ from generation to generation-In peas, both male & female sex cells, called ___________, are in the same flower.-____________________ occurs when a male gamete fuses with a female gamete in the same flower.-Mendel used the technique called _______________ to breed one plant with another.-Mendel studied only one _____ at a time and analyzed his data mathematically.-In a heterozygous genotype, the ________ allele of a trait is hidden by the expression of the other phenotype. In a heterozygous genotype the _________ allele of a trait is visible in the phenotype.

inherited gametes

Self-fertilizations

cross-pollination

recessive

dominant

trait