(03) Pedigrees and Inheritance Flashcards
(Mendelian Traits)
- sometimes referred to as what?
- Convey a distinct _______.
- Traits are controlled by nature of the alleles present at ____ genetic locus (gene).
- “simple” traits
- phenotypic character (either/or). (eye and coat color)
(Mendelian Inheritance)
- gametes are ____. each carries how many alleles of each locus?
- In absence of contrary evidence, it is assumed that segregation at one locus is _______ of segregation at another locus.
- If segregation is not random the loci are said to be _____.
- haploid, one
- indenpendent
- linked
(Single Locus Allele Segregation)
What is homozygous?
Heterozygous?
What does (Aa, Bb) + (Aa, Bb) result in?
- parents produce one type of gamete
- two types
- 9 genotypes, 4 phenotypes
(How Many Gametes?)
- Number of different gametes produced depends on the number of _______.
number of gamete types =
different genotypes =
- heterozygous loci (n)
- 2^n
- 3^n
Basic questions when asked if something is heritable:
Does is run in families? Is it more common within a single or related breeds?
Trait (phenotype) = _____ + _____
What is a congenital defect?
- genotype, environment
- something that is present at birth
What are the two possibilites when something has a congenital defect?
What is more common on a farm, breeding thing, etc?
- genetics or environment
- environment
What causes contracutre-type skeletal birth defects and cleft palate (crooked calf syndrome)?
If lupins are eaten between which days of getation is it most likely to cause brith defects in calves?
What was wrong with the charolis calves that got really tired and died when they worked out a little?
What kind of inheritance whas it?
- lupins in feed (the seeds have flavones and toxic alkaloids
- day 40 to 70
- they had inactive glycogen phosphorylase
(Genetic Defects)
- Abnormality is typically due to how many genes? or a what trait?
- Genetic defects are more likely to occur at a low or high frequency? within related individuals of a similar breed? with repearted matings?
- Do they show unpredicateble patterns of inheritance?
- single gene; polygenic trait
- low frequency; yes; yes
- No - they are predictable
(Why might there be numerous genetic disorders in domestic animals?)
(true or false)
- There usually isn’t a predominance of certain sire lines
- Many breeds start out with a small number of founder animals (80% of thoroughbreds are descendants of 10 stallions)
- Line-breeding (which leads to loss of genetic variation)
- Lack of inbreeding
- F
- T
- T
- F
What is a founder effect?
When there is a bottleneck which leads to a few individuals being the ancestors of many and passing on shitty genes (or at least similar combinations of shitty genes)
Human vs. animal
- average equine stallion might produce 250 offspring (max of 3,000)
- humans - 10 offspring max
Patterns of Mendelian Inheritance
- Autosomal Dominant (A/_)
- Autosomal recessive (a/a)
What is x linked recessive? x-linked dominant?
- Xa/Xa or Xa/Y
- XA/A_ or XA/Y
(Autosomal Dominant)
- Equal frequency of males and females?
- Do they skip generations?
- Affected offspring have at least ___ affected parent
- Normal offspring from affected parents produce only normal offspring when mated to normal individuals
- yes
- no
- one
(Autosomal Recessive)
- equal in males and females?
- A/a + A/a = how many affected?
- can the disorder skip generations?
- Because these are often rare traits - affected x normal matings usually produce _______.
- yes
- 25%
- yes
- only normal
(Autosomal Recessive) (a/a)
If the disorder is rare:
- Most affected individuals will have two normal or abnormal parents? Most matings producing affected offspring will be of what type?
- Carriers will usually mate with homozygous normals, producting _____ of the offspring as carriers
example?
- normal, heterozygous matings (Aa)
- one-half
- pyruvate kinase deficiency
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