chapters 11 & 14
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Chapters 11 & 14. 1. Who is named the “ Father of Genetics ?” 2. Why did he use pea plants?. 1. Gregor Mendel 2. To study the inheritance of traits a nd they reproduced quickly. What is pure bred, true breeding, or homozygous mean? - PowerPoint PPT PresentationTRANSCRIPT
Chapters 11 & 14
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.
How many different gametes would you get from the following parent?
A A B b C c D d E E F F G g H h
First determine how many different letters are there for each letter type then multiply!
A A B b C c D d E E F F G g H h 1 x 2 x 2 x 2 x 1 x 1 x 2 x 2 =
32 gametes
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!
4 Sperm are produced
1 Egg and 3 polar bodies are produced
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
What chromosomal disorder is this on the sex chromosome?
XXY
What chromosomal disorder is this on the sex chromosome?
XO
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
girl50% 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 key, parents’ genotypes, possible gametes, Punnett square,
genotypes and phenotypes of offspring
Doing the different types of Punnett Squares!