korousbiology.weebly.com · Web viewGuided Notes Mendelian Inheritance _____ is the study of _____...
Transcript of korousbiology.weebly.com · Web viewGuided Notes Mendelian Inheritance _____ is the study of _____...
Name __________________________ Period _____
Guided NotesMendelian Inheritance
_________________________ is the study of ___________________________.
Who is Gregor Mendel? _______________________________________________________________”Principle of ______________________________ – Inheritance of one trait has __________ _______________ on the inheritance of another trait.
Law of ______________________ - suggests that __________ __________ (segregate) during gamete formation.
TraitsGenetics – study of how _____________ are passed from ___________ to ______________ Traits are determined by the _____________________________ on the _______________. A gene is a segment of _________ that determines a _________________________ .
Chromosomes come in pairs, thus __________________________ come in pairs.
Homologous pairs – _________________________________ genes – one from female parent and one from male parent
Example: Humans have 46 chromosomes or ________________ pairs.
One set from dad – 23 in __________ One set from mom – 23 in _________
One pair of Homologous Chromosomes:
_____________________ – different ____________________ (possibilities) for the same _______________________
ex: blue eyes or brown eyes
Name __________________________ Period _____
Dominant and Recessive
Mendel’s second Principle is __________________ – Some alleles are dominant and some are recessiveGene that __________________ the other gene from “showing” – __________________
Gene that ___________ _______ “show” even though it is __________________ – __________________
Symbol – Dominant gene – _______ case letter – ____ Recessive gene – _______ case letter – ____
Example: Straight thumb is _________to hitchhiker thumb ____= straight thumb ____= hitchhikers thumb
(Always use the same letter for the same gene)Straight thumb = TTStraight thumb = TtHitchhikers thumb = tt
Must have ____ recessive __________ for a recessive trait to “________”
Both genes of a pair are the same – __________________ or __________________
TT – homozygous __________________ tt – homozygous __________________
One dominant and one recessive gene – __________________ or __________________
Tt – heterozygous
Genotype and Phenotype
____________________ - the combination of genes an organism has (___________________ _________________ ___________________ )
Ex: TT, Tt, tt
– _________________________ - the __________________________ ______________________________ resulting from genetic make-up Ex: hitchhiker’s thumb or straight thumb ______________ determines the ________________.
Notation of Generations (P, F1, F2)
____ _____________ ___________________ - It is the original pair of plants.____ __________ _________ ______________ - The offspring of the P generation.____ ________ _________ ______________ - The offspring of the F1 generation.
Hitchhiker’s thumb
Name __________________________ Period _____
True Breeding vs Hybrid______ ______________ means the organism has a _______ genotype and will only produce offspring that have the same trait as the parents.
___________ means the organism has been produced by parents that have a two different traits, so ________________ _____________ could been seen in the offspring.
Punnett Squares and Probability
________________________- crosses that involve one trait
Punnett Squares are used to _______________ the ________________ gene makeup of ________________
Example: Black fur (B) is dominant to white fur (b) in mice
1. Cross a heterozygous male with a homozygous recessive female.
Male =_________ X Female= ____________
Write the ratios in the following orders:
Genotypic ratiohomozygous : heterozygous : homozygous dominant recessive
Phenotypic ratio dominant : recessive
Genotypic ratio = 2 _____: 2 _____ 50% Bb : 50% bbPhenotypic ratio = 2 ________ : 2 ________
50% black : 50% whiteCross 2 hybrid mice and give the genotypic ratio and phenotypic ratio.
_________ typic ratio = _____: _____ : _____ 25% BB : 50% Bb : 25% bb
_________ typic ratio = __________: __________ 75% black : 25% white
Name __________________________ Period _____
Example: A man and woman, both with brown eyes (B) marry and have a blue eyed (b) child. What are the genotypes of the man, woman and child?Man = _______________
Woman = _____________
Crosses involving 2 traits – Dihybrid crosses
Example: In rabbits black coat (B) is dominant over brown (b) and straight hair (H) is dominant to curly (h). Cross 2 hybrid rabbits and give the phenotypic ratio for the first generation of offspring.
_____ _____ _____ ______
Possible gametes: _______ X ________
Phenotypes: 9______________ _____3 ______________3 ______________ 1 ______________ _____
_____ _____
Example: In rabbits black coat (B) is dominant over brown (b) and straight hair (H) is dominant to curly (h). Cross a rabbit that is homozygous dominant for both traits with a rabbit that is homozygous dominant for black coat and heterozygous for straight hair. Then give the phenotypic ratio for the first generation of offspring.
Possible gametes (genotypes):
Phenotypes:
Name __________________________ Period _____
Genotypic ratio:
Guided NotesOther Types of Inheritance (Non-Mendelian)
Incomplete Dominance and Codominance
When one allele is NOT completely _____________ over another (they __________ ) – ________ _________ Example: In carnations the color red (R) is incompletely dominant over white (W). The ______color is
______. Give the genotypic and phenotypic ratio from a cross between ______ _________ _________.
_____ X ______
Genotypic = ______ :______ : ______Phenotypic = ______ : ______ : ______
When _________ alleles are _________ - ________________
Example: In certain chickens black feathers are codominant with white feathers.
Heterozygous chickens have black and white speckled feathers.
Name __________________________ Period _____
Name __________________________ Period _____
Sex Determination
• People – ______ chromosomes or _________ pairs
• 22 pairs are ____________________________ (look alike) – called _________________________ – determine body traits
1 pair is the ________________ chromosomes – determines sex (male or female)
• Females – sex chromosomes are ___________ (look alike) – label ________ Males – sex chromosomes are ____________ (different) – label _______
What is the probability of a couple having a boy? Or a girl? Chance of having
female baby? _________male baby? _________
Who determines the sex of the child? ________________
Sex – linked Traits
________________ for these ________________ are located ________________ on the ______ chromosome at the 23rd spot (NOT on the Y chromosome)
X linked alleles ________________ show up in ________________ whether ________________ or ________________ because males have only ____________ X chromosome at the 23rd spot
Examples of ________________ sex-linked disorders:
1. _______________________________ – inability to distinguish between certain colors
2. _____________________________ – blood won’t clot
Name __________________________ Period _____
Why are sex-linked traits like color blindness more common in men?
Example: A female that has normal vision but is a carrier for colorblindness marries a male with normal vision. Give the expected phenotypes of their children. N = normal visionn = colorblindness
Phenotype: ___ _________ __________ __________ ___ _________ __________ __________ ___ _________ __________ __________
Name __________________________ Period _____
Multiple Alleles
__________ _____________ ___________ of the __________ gene that code for a _____________ trait.
In humans, _____ ______ is determined by 3 alleles – ____ , ___ , and ____
BUT each human can only ________ ___ alleles1. Dominant – IA and IB (codominance)
Recessive – ii Type O 2. Blood type – A =IAIA or IAi
B = IBIB or IBi AB = AB O = OO
Example: What would be the possible blood types of children born to a female with type AB blood and a male with type O blood?
_____ X ______
Children would be type _____ or ______only
Name __________________________ Period _____
Guided Notes - Applications of Genetics
Pedigrees________________________ representation of how a __________________ is passed from parents to ___________________________
Tips for making a pedigree
1. ___________________________ are for females
2. ___________________________ are for males
3. _______________ ________________ connecting a male and a female represent a _________
4. _______________ _________________ and ___________________ connect parent to offspring
5. A _________________ circle or square indicates a person _____________________ the trait
6. A circle or square _______________________ ________________________ represents an individual who does NOT have the trait
_______________ shade indicates a _______________ – someone who is _____________________for the trait
Make a pedigree chart for the following couple. Dana is color blind; her husband Jeff is not. They have two boys and two girls. Recall that colorblindness is a recessive sex-linked trait. * Label the pedigree with the generation numbers, person numbers, and genotypes of all individuals.
Name __________________________ Period _____
Polygenic Inheritance______________ ________ - a trait that is controlled by __ or more genes.Examples: height, hair color, eye color, skin color
Gene linkage_________ _______________ - Linked genes sit ___________ _______________ on a chromosome, making them likely to be ______________ together (left). Ex: red hair and freckles
Genes on _____________chromosomes are never linked (center).
Not all genes on the same chromosome are linked. Genes that are __________ ________ from each other are more likely to be _______________ during a process called homologous recombination (right).
Pleiotropy_______________ - when one gene mutation results in ____ or more seemingly ______________observable traits. For example, phenylketonuria (PKU), is characterized by intellectual disabilities and reduced skin and hair pigmentation.
A pleiotropic gene can have an effect on a __________ of traits because the gene ___________ more than one _______________.
Epistasis______________- describes a certain relationship between genes, where an allele of one gene ______ or _________ the visible output, or ___________ , of another gene.
Epistasis is seen in the coat color of Labrador retrievers.
-The _______________allele E determines whether the coat will have dark pigment-Allele B determines how ________ the coat will be.-When a dog has recessive ee alleles, the coat will be _____________.
Name __________________________ Period _____
Goodness of fit - Chi Squared test_____ ____________ (χ2) test - a statistical analysis used to determine if _____________ results are statistically valid when compared to the _______________ results.
It allows us to test for ____________________of observed frequencies from expected frequencies.
Karyotypes detect genetic disorders_______________ - a picture of an individual’s chromosomes. It can be used to _______________ chromosomal _______________ .
○ ________________ - a chromosome that is not directly involved in determining the sex of the individual.
○ _____ ___________ - a chromosome that is directly involved in determining the sex of the individual.
_________ _________________ – (Trisomy 21) 47 chromosomes, extra chromosome at pair #21
Klinefelter’s syndrome – 47 chromosomes, ________ X chromosomes (_______) Boys have low _________________ levels, underdeveloped muscles, sparse facial hair.