BIOL133 ACTUAL TEST PAPER COMPLETE QUESTIONS AND ANSWERS FULL SOLUTION.pdf

BIOL133 ACTUAL TEST PAPER COMPLETE
QUESTIONS AND ANSWERS FULL
SOLUTION

●● Genetic variation
Answer: two factors responsible for genetic variation - genes and the
environment


●● Mendelian trait
Answer: trait due to SINGLE gene


●● Multifactorial traits
Answer: traits influenced by enviornment


●● Polygenic traits
Answer: influenced by MORE THAN ONE gene


●● Mendelian traits: "either/or" pattern of inheritance
Answer: ex. pea plants: purple or white
people: Huntington's disease or not


●● Polygenic traits distribution

,Answer: bell curve -continuously varying


●● Quantitative traits
Answer: phenotypes that vary in DEGREE, can be attributed to
polygenic effects
- ex. height, skin color


●● Quantitative traits loci (QTLs)
Answer: section of DNA (locus) that correlated with variation in
phenotype


●● It is ______ to predict recurrence for polygenic traits
Answer: DIFFICULT


●● Empiric risk
Answer: - predictions of recurrence based on trait incidence in specific
population


●● Incidence
Answer: - rate at which event occurs (NEW CASES)


●● Prevalence
Answer: - number of individuals who have a disorder at a specific time

, ●● Heritability
Answer: - % of phenotypic variation due to genes
- H = 1: genes only
- H = 0: environment only


●● Correlation coefficient
Answer: proportion of genes relatives share


●● Heritability
Answer: proportion of people sharing a trait compared to proportion
predicted to share trait


●● Relationships
Answer: - Siblings 1st degree 50%
- Parent and child 1st degree 50%
- uncle/aunt/niece/nephew 2nd degree 25%
- grandparent and grandchild 2nd degree 25%
- first cousins 3rd degree 12.5%


●● Heritability calculation ( proportion)
Answer: people who share trait/people predicted to have trait