Chapter 3 Flashcards
The phenotypic ratio of a heterozygous/homozygous cross is ______
- 1:1
Addition rule
- the probability of one of two or more mutually exclusive events
- get same denominator then add
- “either, or”
Walter sutton and theodor boveri developed __________
- the chromosomal theory of heredity
Crosses of organisms that differ in two characteristics is a _________
- dihybrid cross
To run a test cross you cross an individual with an _______ genotype with a ______ geneotype
- unknown
- homozygous recessive
Autosomal recessive traits
- recessive traits generally skip generations
* start at the bottom most affected individual
In a dihybrid cross Mendel always got a phenotypic ratio of________
- 9:3:3:1
The _________ says that each individual diploid organism possesses two alleles for any particular characteristic. Two alleles ______ into gametes and this occurs randomly in equal proportions
- principle of segregation (Mendels first law)
- segregate
Roll dice once, whats the probability of getting either a 5 or a 6
- 1/6 of getting a 5
- 1/6 chance of getting a 6
1/6 + 1/6 = 2/6, or 1/3
A ________ is the appearance or manifestation of a character
- phenotype or trait
degrees of freedom (df)
df= n-1 n= number of different phenotypes
Only _______ is inherited
- genotype
________ and _______ discovered that homologous pairs of chromosomes consist of one maternal and one paternal
- walter sutton and theodor boveri
Mendels effectiveness was due to
- Choice of subject - easy to grow, grows rapidly
- Had genetically pure stocks of diff types of peas to start studies
- Avoided characters that exhibited variation
- Used “experimental approach” - hypothesis driven
________ recessive traits are never passed down from father to son
- X-linked
A _________ can be achieved by setting out the proportions of genotypes and phenotypes for each allele pair and connecting these to the proportions of the other allele pairs, a branch or web of genotypes or phenotypes can be constructed
- brach diagram
All 7 characteristics mendel studied yields a _______ ratio in the F2 generatiom
- 3:1 ratio
In F1 only ______ phenotype shows up whereas in F2 ______ phenotypes show up in a _______ ratio
- one
- both
- 3 dominant :1 recessive phenotype
What is it called if you cross the other direction?
- reciprocal cross
What is the probability of these (Aa) parents having 3 kids, 1 with albinism(aa) and 2 without
- birth order matters bc there are diff children that can have it, it could be the first, second or third
ANS 27/64
A _____ is an individual possessing two of the same alleles at a locus
- homozygote
For principle of independent assortment to work the characters must be located on ________
- different chromosomes
Consanguinity (incest) is indicated by __________
- a double line
In a ________ parents differ in a single characteristic
- monohybrid cross
The __________ states that alleles at different loci separate independently of one another
- principle of independent assortment
During _______ two alleles separate when gametes are formed, one allele to each gamete one from both parents and separate with equal probability into gametes
- segregation
In a branch diagram you can obtain both ___________ and _________ ratios
- genotypic and phenotypic
A ______ is an attribute or feature
- character or characteristic
The chromosomal theory heredity stated that
- homologous pairs segregate independently at meiosis
A genotypic ratio for a heterozygous cross will result in a ______ ratio
- 1:2:1
Each trait has 2 different _______ that result in different traits and gives _____ possible combinations
- unit factors
- 3
In a cross of TtxTt what are the chances you get a tall plant?
- Tall is TT or Tt
- 1/4 (TT) + 1/4 (Tt) + 1/4 (Tt)= 3/4
In autosomal dominant traits they appear _______ in males and females. Unaffected individuals ______ transmit to offspring, affected individuals have a _____ parent
- equally
- do not
- affected
Different alleles occupy the same locus on _______ chromosomes
- homologous
The phenotypic ratio for a heterozygous cross is ________
- 3:1
If autosomal dominant fill in ___ with all unaffected individuals first
- dd
a ______ is a genetic factor that helps determine a characteristic
- gene
What is the probability of these parents (Aa) having 3 kids with albinism (aa)?
- 1st child AND 2nd AND 3rd
- 1/4 x 1/4 x 1/4
A ______ is a set of alleles that an individual possesses
- genotype
To determine the genotypic and phenotypic ratios use a _________
- Punnet Square
What is the probability of rolling the die twice and getting 4 both times
- independent of eachother
- multiplication rule
- 1/6 x 1/6 = 1/36
A ________ is an individual possessing two different alleles at a locus
- heterozygote
In a homozygous cross traits that were observed in F1 are known as ________ traits and those that disappeared are _________
- dominant
- recessive
autosomal __________ traits can not skip generations if affected
- dominant
What is the probability of getting TT offspring in a TtxTt cross
- prob of T from one parent is 1/2 AND prob of T from the other 1/2
- 1/2 x 1/2 = 1/4
The Chi squared test cannot be used to.. .(1 and 2)
It can be used to…. (3)
- tell us if a cross has been done correctly
- tell us if the results are correct
- it indicates the probability that the difference between the observed and expected is due to chance
autosomal __________ disorders are more common in consanguineous families
- recessive
Chi-Square (X^2) Test
- used to determine the possibility that the difference between the observed and the expected values is due to chance
If P >/= 0.05….
If P< .05…
- differences likely caused by chance (random)
- assume chance is NOT responsible and a significant difference exists
___________ are pictorial representations of a family history
- Pedigrees
A _____ is one of two or more alternative forms of a gene
- allele
A genotypic ratio for a heterozygous and homozygous cross is _______
- 1:1
Two alleles segregate during _______ or _______ (depends on whether or not crossing over has occurred)
- anaphase 1 or 2
Multiplication/Product Rule
- events must be independent
- use when you see the word AND
- multiply fractions across the top then across the bottom
Chi Squared Formula
X^2= (#observed-#expected)^2 / (#expected)
- do this for all classes then add the results of both
A ______ is a specific place on a chromosome occupied by an allele
- locus
Mendel studied genetics using ________ as his subject
- pea plants
To determine whether something is homozygous or heterozygous use a ________
- test cross
