Review Day!

• Pick up paper: “Genetics Challenge”• Take out a full sheet of paper, we’ll be

answering questions again • Only pick up a Review Packet if you don’t

already have one.

Unit 6 Review

1. Who is named the “Father of Genetics?”

2. Why did he use pea plants?

1. Gregor Mendel

2. To study the inheritance of traitsand they reproduced quickly

1. What is pure bred, true breeding, or homozygous mean?

2. What type of offspring results when you cross two pure “true” breeding parents with different traits?

3. What are the offspring of two parents called?

1. Both alleles are either dominant or recessive AA or aa

2. All hybrid (Aa) offspring result

3. F1 generation Aa

What results when the offspring (F1) of true breeding parents self-pollinate?

R r

R

r

RR Rr

Rr rr

Genotype Ratio: 1 RR: 2 Rr: 1 rr

Phenotype Ratio: 3 Round: 1 Wrinkled

Rr x Rr

1. What is probability?

2. What is the probability of getting heads when you flip a penny?

1. Probability: The chance of something happening!

2. ½ or 50%

Why did we keep increasing the number of flips of our penny in the “Coin Toss” lab?

The higher the number of trials you perform, the more likely you are to get the expected outcome (probability).

½ heads, ½ tails

If you toss a coin 6 times in a row, what is the probability it will land heads for all 6 tosses?

If you toss a coin 6 times in a row, what is the probability it will land heads for all 6 tosses?

½ x ½ x ½ x ½ x ½ x ½

= 1/64

What is the “Principle of Independent Assortment?”

During gamete formation, genes for different traits separate without influencing the other.

Foil each parentto get 4 gametes

G g Y y

GYGygYgy

Be able to define: Complete Dominance Incomplete Dominance Co-Dominance

Complete DominanceThe dominant trait (G) over shadows the recessive trait (g) and only the dominant trait shows up in the phenotype.

Incomplete DominanceNeither trait is dominant over the other and a new trait is displayed. BLENDING!!!Red flowers crossed with white flowers make pink flowers.

Co-DominanceBoth traits are equally displayed and neither is dominant over the other.ABO blood types: A blood x B blood = AB blood

Describe the genotypes and phenotypes of each blood type:

Type A

Type B

Type AB

Type O

Describe the genotypes and phenotypes of each blood type:

AB has same genotype and

phenotype

What are polygenic traits?

What are polygenic traits?Traits that have a wide variety of color ranges such as eye colors, hair color, skin color.

Can this parent AaBBccDdeeFfGgHH

have a child with the following genotype? Why or why not?

A A B b C c D d E E F F G g H h

Can this parent AaBBccDdeeFfGgHH have a child with the following genotype? Why?

NO, because the parent would need to have a big E in their genotype in order for the child to have 2 EE’s.

A A B b C c D d E E F F G g H h

Know what forms from the sex cells in females and males!

FemaleMale

The paired, homologous chromosomes come together during Meiosis I to make Tetrads

The chromatids pull apart during Meiosis I I

4 genetically different cells result at the end of MeiosisHaploid = one set of chromosomes

Know the stages of Meiosis I & II

When does crossing over occur during Meiosis?

Why is this important?

During Prophase I

Importantfor GENETICDIVERSITY!!

XXX

X

Diploid Parent SsTt

S

s

T

t

XX X

S s

Tt

X

What are the four possible combinations for the haploidcells?

ST

XX X

S s

Tt

Xl l

St

l l

sT

l ls

tl l

STSt

sT st

1.What is this picture called?2.What 4 things are shown from this

picture?

1.What is this called? Karyotype2.Shows:• Autosomes = all chromosomes # 1 - 22

chromosome pairs (not sex chromosomes)• Sex Chromosomes

(XX= female or XY= male) # 23 pair• Homologous Chromosomes =

chromosomes that code for the same traits and pair up with each other

• Inherited Disorders (ex: Down’s, Turner’s, Kleinfelter’s, Super males/females)

What is non-disjunction?

Non-disjunction –When chromosome pairs don’t separate properly during Meiosis ICan involve all types of chromosomes (sex, autosomes, homologous)

What chromosomal disorder is this on the #21 pair?

#21

Down’s Syndrome (Trisomy 21)

#21

What chromosomal disorder is this on the sex chromosome?

XXY

XXY

Kleinfelter’s Syndrome

What chromosomal disorder is this on the sex chromosome?

XO

XO

Turner’s Syndrome

Who determines the sex of the offspring? Mother or Father

Why?

What is probability of getting a girl? A boy?

Fatherdetermines

sex of offspring

He provides either an X or a

Y to pair up with the

mother’s X to make a boy or

girl

50% chance of Boy 50% chance of Girl

•What is this picture called?•What do each of the shapes and shading

combinations represent?•How many generations are shown?

Pedigree Chart = shows how a trait is passed from one generation to the next.3 Generations

Normal Male

Normal Female

Female with Trait

Carrier Female

Male with Trait

Carrier Male

Line = Marriage

Be able to describe the differences between:

Meiosis and Mitosis

Be able to describe the advantages and disadvantages between:

Asexual and Sexual Reproduction

Mitosis Meiosis

Somatic Cells – all body cells

Sex Cells - gametes

2 cells are made 4 cells are made

Diploid Haploid

Asexual Reproduction Sexual Reproduction

Advantages No mate needed for

reproduction Very fast reproduction time Lots of organisms

Advantages GENETIC DIVERSITY!

Disadvantages All organisms are alike, No Genetic Diversity

Disadvantages Need a mate for reproduction Slower reproduction time Fewer organisms

Know the term Sex-linked genes/traits and how the key and Punnett square

would look. What chromosome carries these types of traits?

XB Xb

Xb XBXb XbXb

Y XBY XbY

XBXb x XbY female carrier x male colorblind

Phenotypes: 1 Female/Carrier 1 Female/Colorblind1 Male/Normal 1 Male/Colorblind

??

Know the term Sex-linked genes/traits and how the key and Punnett square would look. What chromosome carries these

types of traits?

XB Xb

Xb XBXb XbXb

Y XBY XbY

XBXb x XbY female carrier x male colorblind

Phenotypes: 1 Female/Carrier 1 Female/Colorblind1 Male/Normal 1 Male/Colorblind

Sex-linked traits only carried on X Y doesn’t carry traits

Sex-linked gene/trait – Traits linked to sex chromosomes such as hemophilia or colorblindness

Know the definitions of the following vocabulary terms:

• Allele•Gametes•Genes•Genetics• Karyotype• Pedigree• Probability• Punnett Square

• Allele- Different forms of a gene•Gametes- Sex Cells (egg & sperm)•Gene- Part of a chromosome; codes for traits•Genetics- Study of how traits are passed

generation to generation• Karyotype- Picture of all chromosomes matched

up - looking for sex and the presence of abnormal # of chromosomes

• Pedigree- Family tree (picture) shows passing of trait from one generation to the next generation• Probability - Chance of something happening• Punnett Square- Chart showing offspring’s trait

probabilities

Know the definitions of the following vocabulary terms:

•Dominant• Recessive•Genotype• Phenotype•Heterozygous•Homozygous• Trait•Homologous

•Dominant – Gene whose effect masks the partner (recessive) trait• Recessive – Gene whose effect is masked by

partner (dominant) trait•Genotype – Genetic makeup of organism (letters)• Phenotype – Trait expressed “physical” looks•Heterozygous – Pair of different alleles (Rr)•Homozygous – Pair of same kind of alleles (RR) (rr)• Trait – Inherited characteristic (feature)•Homologous – Pair of same kind of chromosomes

Know the definitions of the following vocabulary terms:

• Co-dominance• Incomplete dominance•Diploid•Haploid• Independent Assortment•Non-disjunction• Segregation

• Co-dominance – Both alleles expressed EQUALLY• Incomplete dominance – Blending of traits•Diploid – Having 2 sets of chromosomes•Haploid – Having 1 set of chromosomes• Independent Assortment – Genes that separate

have no effect on the other’s inheritance•Non-disjunction – When chromosomes don’t

separate• Segregation – Separation of alleles

Understand which is the P, F1, F2 generations and how you get each.

Know how to do the following types of crosses:

•Monohybrid Cross•Dihybrid Cross

•Incomplete Dominance Cross•Sex-linked Cross

Must show: parents’ genotypes, possible gametes, Punnett square,

genotypes and phenotypes of offspring

Practice doing the different types of Punnett Squares!