1
Q
What is blending ?
A
- mixing of two characteristic and getting out the average
- which does not work cuase then all phenotypes would be equal
2
Q
What is the structure of mendal experimnets regarding white and purple flowers ? And what were the results ?
A
- P1 generation true breedings crossbreed
- F1 hybrid all purple after crossbreed again
- F2 3/4 purple and 1/4 white
- > heritable factor white flowers are not lost just unexpressed
3
Q
What is an allele ?
A
- genotype Aa
- A is an allele
- a is also an allele
- > varaiations of characteristics
4
Q
What is homozygous ?
A
- pair of identical alleles (PP/pp)
5
Q
What is Heterozygous ?
A
- two different alleles for a gene (Pp)
6
Q
What is a dominant allele ?
A
- heterozygous allele Pp
- > large P determins characteristics
7
Q
What is a rezessive allele ?
A
- heterozygous allele Pp
- > small p no noticable effect
8
Q
Draw a punnett square !
A
- remeber addition and multiplication rules
9
Q
What is the law of segregation ?
A
First mendel experiment !
- allele get split randomly during meiosis
- only regarding one trait
- 3 to 1 in F2 generation
- during gamete formation
10
Q
What is the law of Independent Assortment ?
A
Second experimnet
- two traits
- ratio 9:3:3:1
- it describes independent corelation of two allele !
- during gamete formation
- All possible trait combination outcomes
11
Q
Why should we aviod inbreeding according to mendel ?
A
- recessive deleterious allele will not be expressed if there is no other recessive deleterious allele
- but your siblings mostlikly have the same so it is more likly that that allele will be epxressed in offspring
- > Mendelian Diseases
12
Q
What is complete dominance ?
A
- AA has the same phenotype as Aa you can not distingluish between them
- normal dominant allele
13
Q
What is incomplete dominance ?
A
- Phenotype of AA and Aa is different
- Aa = mixture of P1 generation
- due to parental FREQUENCIES of allele
- combination of Frequencie dominant allele determine color
14
Q
What is co dominance ?
Give an example were this is often present !
A
- AB (dominant) will be crossed with AB (dominant no rezessive) and then we would have 3 outcomes
- 1 Completly red (A)
- 1 completly white (B)
- 2 White and red not mixed !
- BLood groupd
15
Q
What is pleiotropy ?
A
- one gene can code for more then one phenotype
- A = would stand for BLURE RED and YELLOW
16
Q
What is Epistasis ?
A
- When one gene depens on another gene to be expressed
17
Q
Does the enviorment has an effect on phenotypes ?
A
- Yes
18
Q
What happens during meiosis ?
A
- paired chromosomes exchange dna structure
- called: crossing over !
19
Q
Name the two types of crossing over:
A
- Parental type:
offspring phenotypes which exist in both parents - Recombinants: phenotypes which were diff in both parents
20
Q
How does natutal selection determine the best fitting allele ?
A
- interplay between environment and genotype -> will deterimne which genitc combinations will persist over time
21
Q
What is gene pool ?
A
- consists of all copies of every type of allele at every locus from all members of the population
22
Q
What is a fixed allele ?
A
- one allele exists for a particular locus in the population
23
Q
What are the conditions for the Hardy weinberg equiliburum ?
A
- no mutation in gene pool, random mating no natural selecetion, large population, no gene flow.
24
Q
How does natural selection happen accorrding to Hardy-Weinberg ?
A
- when frequencies changes
25
What is the hardy weinberg formula ?
- p^2+2pq+q^2 = 1
- p = homozygous dominant
- q = homozygous rezessive
26
What is gentic drift ?
- When frequencies of one allele dramticall increase and the other decrease -> this can lead to fixation: An allele that everyone has
27
What is the neutral theory of molecular evolution ?
- The more difference there is between the DNA sequences of twó animals, the greater the time since their common ancestor
- Metaphor: molecular clock
28
What does heritability mean ?
- estimates the degree of variation in a phenotypic trait in a population that is due to genetic variation
- depends on genotypic variation
- depends on enviormental variation
29
What would heretiablity look like if it depends completly on genetic or completly on enviorment ?
- 1 = gentic
| - 0 = enviorment
30
What are complex traits and give some examples ?
- They do not follow Mendalian propotions
- So it is not just rezessive or dominant
- Enviorment has an huge impact on traits
- Example: Schizophrenia and general cognitve abiltys
31
What is a polygenic trait ?
- complex traits that are influenced by several genes
32
What is the coefficient of relatedness ?
- probability that any two allele in two individual derived from the same immediate source
33
What are monzygotic twins and dizygotic twins ?
- Mono = identical r=1
| - Diz = not identical r= 1/2
34
What is the benefit of twins study ?
- eviormental factor are most likly 100% equal
| - MZ twins any phenotypic differences must be due to NSEI (non shared enviormental influences)
35
What is the Falconer heritablity formula ? And what does it determine ?
- 2 x (rmz – rdz)
- > rmz and rdz are given
- > relative contribution of genetics vs. environment to variation in a particular trait
36
What is the ACE model ?
- A= Heritability
- C = effect of shared enviorment
- E = effect of non shared enviorment
- > based on addition
37
Why are adoption studies so relevant ?
- showes you the complete enviormental facors
| - all based on genetic or nothing depens on gentic factors
38
What were some problems rgarding Adoption studies and twin studies ?
Twin studies:
1. treat their MZ twins more similarly than they do their DZ twins
2. two-thirds of MZ twin pairs share a placenta, whereas no DZ twin pairs do
- > so allready shared enviorment
39
What is the dominance effect ?
- Due to interaction between the pair of alleles at a locus
40
What is the epistatic effect ?
- Due to interactions between alleles at different loci
41
What did the IQ study in different enviorments show ? (ACE model)
- If you live in an sufficient/high enviorment then A the additive genetic effect is the most important factor regarding IQ
- A was = for poor enviormental factor
- If not then the enviorment had an huge impact
42
Name the top 10 replicated findings from behavioral genetics: How does genetic influence behavior ?
1. All psychological traits show significant and substantial genetic influence
2. No traits (behavioral) are 100% heritable
3. Heritability is caused by many genes
4. Phenotypic correlations between psychological traits show significant genetic impact
5. The heritability of intelligence increases throughout devlopement
6. Age-to-age stability is mainly due to genetics ( increase (a lot ) of one gene propotinal to another gene (basically trough out life you gain more gene expression and you become simmilar to your parents)
9. Most environmental effects are not shared by children growing up in the same family (different enviorment growing up)
43
What is linkage/dependent assortment ?
- opposite of independent assortment
- when 2 traits are linked together to one because the allele lies right next to each other on same the chromosome (exchange together)
3;1
- during recombination
(exchange together)
44
in an extrem cas of disrpupitve selection what can happen ?
- out of the two extrem their could be a new species
Evolution and genetics
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