1. Parents First Generation Second Generation
Section 11-1
Parents
Long stems  short stems
Red flowers  white flowers
Green pods  yellow pods
Round seeds  wrinkled seeds
Yellow seeds  green seeds
First Generation
All long
All red
All green
All round
All yellow
Second Generation
787 long: 277 short
705 red: 224 white
428 green: 152 yellow
5474 round: 1850 wrinkled
6022 yellow: 2001 green
1. In the first generation of each experiment, how do the characteristics of the offspring compare to the parents’ characteristics?
2. How do the characteristics of the second generation compare to the characteristics of the first generation?
Go to Section:

2. Heredity: The transmission of traits from parents to offspring.
Who was Gregor ____________?
Austrian monk and high school teacher born in ___________.
Father of _______________(1800’s) study of_______________
Modern genetics is a core theme___________.

3. Mendel’s data revealed patterns of inheritance.
Mendel made ____________________in his experiments.
use of ________plants
control over __________=observation of seven “either-or” traits

4. 4 stock plants:
Tall/Short Green/Yellow seeds
The peas were self pollinating and producing an exact copy of the parent plant. (True Breeding)
Mendel cross bred the seeds and got hybrid pea plants.
How ? He took pollen from the male structures (anthers) of a tall plant and placed it on the female structures (pistil) of a short plant.
All of the offspring were hybrid tall (F1).

5. Why? Grow ___________________in very little space.
A. Mendel’s Peas
Chose garden peas to test.
Why?
Grow ___________________in very little space.
True-breeding peas - all offspring show the same ______________after generation (homozygous).
Variety of _______________to study (tall v short, white v purple, etc.)
Easy to ____________because closed flower doesn’t let random sperm/pollen in!

6. 4. Easy to control breeding
male & female parts are in a closed flower – other plant pollen can’t get in.
a) self-pollinate – fertilization in a single plant using ________(sperm) and ____to make a zygote (seed!)

7. b) cross-pollination breeding ___________plants
Mendel wanted to study the results of breeding 2 different plants, so he had to prevent self-pollination.
b) cross-pollination breeding ___________plants

8. B.Mendel’s experiments
Mendel studied__________________.
What is a trait?
A specific________________________.
P Generation are the parent plants.
F1 Generation are the 1st generation plants.
F2 Generation are the 2nd generation plants.
__________________and studied the results using math.
Can’t study them all at once
Mendel studied _______________(1 variable) = good science!

9. Bred true breeding plants.
True tall to true short.
P = ______________parents (homozygous)
Tall x short
b) F1 = ____________(offspring of P, heterozygous)
all tall
P - parent
F2 –second filial
F1 –first filial

10. 2. Bred F1 x F1 F2 = ______________(offspring of F1) 3 tall:1 short
F2 –second filial
P - parent
F1 –first filial

11. Mendel’s work led to 2 laws.
_________________: Members of each pair of alleles separate when the gametes are formed. (Homologous Chromosomes separate)
___________________: Pairs of alleles separate independently of one another during gamete formation.

12. What do the results mean?
_______________are passed unchanged as a unit
No blending!
Genes – DNA sequence on a chromosome that codes for specific protein(s) that determine traits (The ____________that determine traits.)
Alleles - different expressions of same gene for same trait
Ex: one allele codes for tall, one allele codes for short but both the same ______________for height

13. What do the results mean?
_________________– during gamete formation, alleles separate so you only inherit one copy of each gene from each parent
F1 had to have both alleles to get a short plant in F2, so the allele for shortness had to be separated from the allele for tallness when passed to the F2.
homologous chromosomes must separate
When does this happen during sexual reproduction???
MEIOSIS! Anaphase I

14. What do the results mean?
3. ____________of Dominance – one allele can mask another allele. Tall allele dominated short allele. ____________– allele or trait that is seen when present, masks recessive allele. Capital letters: A _____________– allele or trait that is only seen if the dominant trait is NOT present. Lower case letters: a

15. Mendel drew three important conclusions.
Traits are inherited as_________________.
Organisms inherit_________________, one from each parent.
The two copies_______ during ________formation.
The last two conclusions are called the law of segregation.
purple
white

16. 4. How do the expected results differ from the observed results?
Interest Grabber continued
Section 11-2
1. Assuming that you expect 5 heads and 5 tails in 10 tosses, how do the results of your tosses compare? How about the results of your partner’s tosses? How close was each set of results to what was expected?
2. Add your results to those of your partner to produce a total of 20 tosses.
Assuming that you expect 10 heads and 10 tails in 20 tosses, how close are these results to what was expected?
3. If you compiled the results for the whole class, what results would you expect?
4. How do the expected results differ from the observed results?
Go to Section:

17. Genes and Physical Traits
__________– genetic makeup of alleles
Geno = “genes”
Ex: AA, Aa or aa; dominant or recessive, heterozygous or homozygous
_____________– physical expression of traits or what organism looks like!
Pheno = “to show”
Ex: tall or short, green or yellow, blue eyes or brown eyes

18. Having two identical alleles for a trait.
What is homozygous?
Having two identical alleles for a trait.
Homozygous Dominant –________________= AA
Homozygous Recessive –________________= aa
What is heterozygous?
Having _____________alleles for a trait. = Aa

19. The same gene can have many versions.
A gene is a piece of DNA that directs a cell to make a certain protein.
Each gene has a______, a specific position on a pair of ___________chromosomes.

20. An allele is any _____________________occurring at a specific locus on a chromosome.
Each parent donates one allele for every gene.
Homozygous describes two alleles that are the same at a specific locus.
Heterozygous describes two alleles that are different at a specific locus.

21. Alleles can be represented using letters.
A dominant allele is expressed as a phenotype when at least one allele is dominant.
A recessive allele is expressed as a phenotype only when two copies are present.
Dominant alleles are represented by _________ letters; recessive alleles by _______________ letters.

22. Both ________________________________ genotypes yield a dominant phenotype.
Most traits occur in a range and do not follow simple dominant-recessive patterns.

23. Probability and Punnet Squares
Whenever Mendel crossed two hybrid plants (F1), he got 3:1 ratio or ¾ dominant and ¼ recessive.
Mendel realized that the
principles of probability
(MATH!!) could be used
to explain the_________
_____________________

24. Genetics and Probability
Probability - the likelihood that any particular event(s) will occur
Ex: coin flip – probability of heads is 1 chance out of 2 possible outcomes = 1/2, or 50%.
Does heads on the first flip change the probability of heads on the next? What if heads 10 times in a row – will next flip be more likely tails?
_____________do not affect future ones
With the coin flip there are two possible outcomes – head or tail
Chance for heads – 1 out of two
Now flip it three times – the chance of getting heads is still 1 out of two, but it applies to each of the three times – 1 out of 8
Previous flips do not affect the current.
We can use probability to predict genetic cross outcomes.

25. Genetics and Probability
What is the probability that we will flip heads three times in a row?
Because each event is independent :
(probability of event)N = number of events or
½ x ½x ½ = (½)3 = 1/8
1 in 8 chance that 3 heads flipped in a row

26. Genetics and Probability
How is this related to genetics?
Allele segregation is ______________and each event
______________________
_____________________a given allele from a heterozygous parent = 50% or 1/2
If parent, T or t – you have a 50% chance of either, same as heads or tails

27. Probability and Gender
Females = ________________
What is the probability that you will inherit an X from your mother?
Males =__________________.
What is the probability that you will inherit an X from your dad? Probability of a Y?
What is the probability of having a boy? Having a girl?
Which parent’s genes determine your gender?
What is the probability that a family with three children will have all girls?
(probability of event)N = number of events
½ x ½x ½ = (½)3 = 1/8

28. Why ________________squares?
Predicts the probability of a cross between two organisms.
Rules:
Dominant allele represented by a Capital letter.______________
Recessive allele represented by a lower case letter _____________
The letters designate the two forms of one gene, the two alleles for a monohybrid cross.
Every cell in your body has at least two alleles for every trait, one from Mom and one from Dad)

29. Punnet Squares
Punnett square – grid showing possible gene combinations for offspring from a given genetic cross.
predicts ______________and their probability
Shows phenotype &__________________________

30. Setting up a Punnett Square
Determine _________genotype.
_______for dominant, lower case__________.
Top and left letters =____________________
Bring down from top and over from left to create possible ______________________for offspring.
Short plant x
Tall heterozygote Tt Tt tt tt

31. Ratios and Punnett Squares
________________– number of each type of offspring genotype predicted by punnett square
For a single trait (_________________) –
homozygous dominant: heterozygous: homozygous recessive
#TT : #Tt : #tt
________________– number of each type of offspring phenotype predicted by a punnett square
____________________traits
#Tall : #short

32. Monohybrid Cross:
Provided data for one pair of contrasting traits.
What are the possible genotypes that can result?
What are the possible phenotypes that can result?
What is the ratio of tall to short plants in a hybrid cross?
Does this ratio agree with Mendel’s result in the F2 generation?

33. A monohybrid cross involves one trait.
Monohybrid crosses examine ____________________ specific trait.
homozygous dominant-homozygous recessive: all heterozygous, all dominant

34. heterozygous-heterozygous—___________________ dominant: heterozygous:homozygous recessive; 3:1 dominant:recessive

35. heterozygous-homozygous recessive—1:1 heterozygous:homozygous recessive; 1:1
__________________________
A testcross is a cross between an organism with an unknown genotype and an organism with the recessive phenotype.

36. _____________________involves two traits.
Mendel’s dihybrid crosses with heterozygous plants yielded ________________phenotypic ratio.
Mendel’s dihybrid crosses led to his second law, the law of independent assortment.
The law of independent assortment states that allele pairs separate independently of each other during meiosis.

37. Law of Independent Assortment
genes for different traits can ____________________during the formation of gametes.
Independent assortment =____________________
Mendel concluded that the inheritance of one trait does not influence the inheritance of a second trait

38. Independent Assortment occurs in __________________
R = round
r = wrinkled
Y = yellow
y = green R y Y r

39. Heredity patterns can be calculated with probability.
Probability is the likelihood that something will happen.
Probability predicts an average number of occurrences, not an exact number of occurrences.
Probability =
number of ways a specific event can occur
number of total possible outcomes
Probability applies to random events such as meiosis and fertilization.

40. Probability and Punnett Square
Probabilities predict averages,
_____________
outcomes
Probability is more accurate when you have more chances
Just as when you flip a coin twice, you may get one head and one tail OR you may get two heads OR two tails
To get the expected 50:50 ratio you would have to flip the coin many times.
This true for genetics – the more offspring you have, the closer to the expected values you will be.

41. DIHYBRID CROSS
Crossing organisms with genes for two different traits = _______________possible gametes. If we cross RRYY with rryy – what are the possible gametes?

42. DIHYBRID CROSS : punnett square for true breeding or homozygous parents.
R = round
r = wrinkled
Y = yellow
y = green

43. heterozygous
Offspring have combinations of alleles ________in earlier generations = ______________ independently

44. ___________________from dihybrid cross of heterzygotes = 9:3:3:1

45. Summary of Mendel’s Principles
Traits come from your__________________.
_____________________________allele and some are dominant.
Your two copies of each gene (one from each parent) are _________________when gametes form.
Alleles for different genes usually segregate
__________________________of one another.

46. Interest Grabber
Section 11-3
Height in Humans
Height in pea plants is controlled by one of two alleles; the allele for a tall plant is the dominant allele, while the allele for a short plant is the ecessive one. What about people? Are the factors that determine height more complicated in humans?
Go to Section:

47. KEY CONCEPT Phenotype is affected by many different factors.

48. Genetics can be affected by 5 other different heredity patterns.
__________________Dominance
___________________
_________ Traits (Multiple Genes)
_____________ Influences

49. Phenotype can depend on________________________.
In incomplete dominance, neither allele is completely dominant nor completely recessive.
Heterozygous phenotype is intermediate between the two homozygous phenotypes
Homozygous parental phenotypes not seen in F1 offspring

50. neither allele is completely dominant so _________________________
1. Incomplete Dominance
neither allele is completely dominant so
_________________________
cross between red-flowered (RR) and white-flowered (WW) plants consists of pink-colored flowers (RW).
What happens if you breed the pink flowers?

51. Codominant alleles will both be____________________.
Codominant alleles are neither dominant nor recessive.
The ABO blood types result from codominant alleles.
Many genes have more than______________________

52. both alleles expressed in the phenotype –____________________.
2. Codominance
both alleles expressed in the phenotype –____________________.

53. What are ____________ alleles?
Genes that have more than two alleles for a trait. Example: ____ type in humans
What are ______________ traits?
Traits that are controlled by two or more genes. Example: _______in humans.

54. 3. Multiple Alleles
Genes with more________________________
This does not mean that an individual can have more than two alleles. It only means that more than two possible alleles exist in a population.
One of the best-known examples is blood type in humans.

55. _______type alleles gene:
Human Blood Types
_______type alleles gene:
A = makes A surface protein
B = makes B surface protein
O doesn’t make either.
____________alleles are codominant to each other & both __________over recessive O allele.
Is your blood type a genotype or phenotype?

56. 4. Polygenic Traits
Traits controlled by interaction of two or more genes
_____________=“many genes.”
Ex: Hair color, eye color, skin color all the result of several genes

57. Environmental Influence:
Phenotype can depend on conditions in the environment.
Conditions can cause a gene to _______
__________________ in coat color.
This allows the animal to blend in with its background.

58. ENVIRONMENT INFLUENCES ____________TRAITS
I got the “fat” gene.
Environment factors like diet, exercise, exposure to toxic agents, or medications can all influence our genes and traits.

59. Concept Map Gregor Mendel Pea plants “Factors” determine traits Law of
Section 11-3
Gregor
Mendel
experimented with
concluded that
Pea
plants
“Factors”
determine
traits
Some alleles
are dominant,
and some alleles
are recessive
Alleles are
separated during
gamete formation
which is called the
which is called the
Law of
Dominance
Segregation
Go to Section:

60. Linked Genes
Mendel concluded that traits are assorted independently, but some traits are Linked
Linked genes: Genes usually _________________because on same chromosome

61. Genes on the sex chromosomes are linked.
Sex-Linked Genes
Genes on the sex chromosomes are linked.
i. _________ genes Y has few genes – mostly gender determining (boy or girl).
Y only in males so these genes only affect males.
ii. _______________ Many genes on X chromosome
Affects mostly males because only________________
Male copy of _____________(Dad gave Y to son)
Females less affected because ______________= have to inherit trait from both parents.
Heterozygous females are _____________________traits.
EX: baldness, colorblindness

62. Crossing Over affects linked genes.
Crossing over – exchanging DNA during prophase
Genes _______on the chromosome _______ likely to be separated by crossing over.

63. Chromosome Mapping
The farther apart genes are, the higher probability that they will be separated by crossing over.
Scientists conduct experiments to determine how frequently genes of a particular trait are separated from one another.
Chromosome map - _______________sequence of genes on a chromosome.
Two genes that are separated by crossing-over 1 percent of the time are considered to be one________________.

64. Summary of Mendel’s Principles
Traits come from your__________________.
Genes may have ______________and some are dominant.
Your two copies of each gene (one from each parent) are ________________________when gametes form.
Alleles for different genes usually ______________
________________ of one another.

65. Beyond Mendel – Other Patterns of Inheritance
Most genes have more than two alleles.
Some alleles are neither dominant nor recessive (codominance & incomplete dominance)
many traits are controlled by multiple genes.
Some genes are linked and do not segregate independently - on the same chromosome so inherited together.