Flashcards
Genetics and Evolution IV
Flashcards do conjunto (22)
- 1What is an autosome?A non-sex chromosome that appears in equal frequencies between sexes
- 2What is autosomal dominant?Affected individuals have at least 1 affected parent (unless mutation has appeared de novo)
Trait usually doesn't skip generations. - 3What is autosomal recessive?Infantile onset epilepsy (GM3 synthase)
Cystic fibrosis
Phenylketonuria
Appears both sexes w/ = frequency
Parents can be unaffected
Parents often related, although this depends on allele F in the population
trait frequently skips generations - 4X-linked recessiveRed-green colour blindnes
Haemophilia
Appears in men more frequently than women
Parents can be unaffected
Fathers don't transmit to sons
trait often skips generations. - 5X-linked dominantFamilial vitamin-D-resistant rickets
Appears in females more often than males
at least 1 parent affeted (unless de novo)
Fathers don't transmit the train to their sons, do pass it to daughters
Trait doesn't skip generations. - 6What is incomplete dominance?Heterozygote of 2 incompletely dominant alleles has an intermediate phenotype between the 2 homozygotes e.g. red+white=pink.
- 7What is co-dominance?Heterozygote between 2 co-dominant alleles has the some of the 2 phenotypes
- 8What is overdominance or heterozygote advantage?Fitness of heteroz > either homoz
Sickle cell disease
cystic fibrosis
A disease allele is present in the gene pool at higher f than would be expected given the nature of the disease - 9What is under-dominance or heterozygote disadvantage?Homoz of either allele's fitness > heteroz
Chromosomal rearrangements
Significant implications for speciation because it typically causes the population to fix one of the two alleles
This can reduce immigration potenetial and lead to populations becoming genetically isolated - 10What is an example of this?Human chromosome 2 formed from a fusion of 2 ancestral chromosomes
Should have been selected against in heterozygotes with the non-fused chromosomes
Would have lead to gametes either missing or having extra chromosome arms, ergo missing/extra genes
Fusion would only survive in very small populations here inbreeding and genetic drift is present. - 11How could this have arisen in the germ line?Rearrangements in premiotic germ cells of an individual leading to more than one sibling offspring with the same rearrangement.
If these siblings mate some of their progeny could be homozygous for the fusion chromosome only 2 generations after the genetic change - 12What is an allele series?Multiple alleles of an individual lous
- 13What is a "wild type" allele?An allele that is overwhelmingly common in a population
- 14What are polymorphic alleles?Loci controlling a highly variable train in a population e.g. hair colour
- 15What does the ABO locus encode?A glycosyltransferase
- 16What is the most common O alleleMost common O allele has a 1bp deletion (relative to allele A)
This results in a frameshift and so no active protein is produced. - 17What does allele A encode?GST-A which adds alpha-N-acetylgalactoserase residue to the chain
- 18What does allele B encode?GST-B, which adds an alpha-galactose residue to the chain
- 19How can a single allele be both dominant and recessive?Can be dominant wrt to one trait and recessive to another
In Drosophila many alleles that confer a dominant viable phenotype are also recessive elthal
Similarly, in humans dominant viable alleles (e.g. skeletal defects) are not viable as homozygotes
So if 2 D's are brought together, they compete like 2 charging bulls and their collision is lethal - 20What is pleiotropy?When a single mutation can affect multiple processes
Many gene products function in multiple contexts in the organism
mutating the gene ill result in a variety of defects.
e.g. protein phosphatase 1 - 21Gives us a rundown of PP1Catalytic SU binds to different targeting/regulatory SU
Each cat/reg SU complex has a distinct target specificity
Mutating catalytic SU creates a broad range of phenotypes, reflecting the function of this protein in many different biological contexts - 22Do a big fuck off thing showing dominance versus recessiveSickle cell anaemia
Homoz WT HbβA/HbβA
Normal RBC
Homoz defective HbβS/Hbβs
Sickle cell anaemia
Heteroz HbβA/Hbβs
No disease
Informações
- Descrição
- O usuário eliminou as informações de disciplina FlashCards sobre Genetics and Evolution IV, criado por Usuário eliminado em 05-03-2018.
- Criado por
- Usuário eliminado · mar 2018
- Atualizado
- 5 mar 2018
- Visualizações
- 21
- Histórico
-
- Criado por J yadonknow · 27 fev 2018
- Copiado por J yadonknow · 5 mar 2018
- Avaliação