Topic 4 - Genetic Diversity & Adaptation Flashcards
Enzyme B breaks down a particular substance. Enzyme B has two alleles B^ and B. The enzyme encoded for by B breaks down the substance faster. Suggest why.
- Diff primary structure
- Diff tertiary structure
- Diff AS shape
- enzyme-substarte complexes more likely to form with enzyme B*
Suggest why a scientist took samples from the pop at random?
- eliminate bias
The substance enzyme B breaks down is toxic. Suggest & explain why the freq of B* allele changed during 45 generations.
What type of selection is being investigated here?
- organisms with B* better adapted to survive
- meaning they survive and reproduce
- passing beneficial trait onto offspring
- occurs over many generations
- inc freq of B* over many generations
- Directional selection
Evaluate effect of named variable on deaths in babies before they turn 4 weeks old using graph linked w birth masses.
- does survival inc as birth mass inc or no?
- does survival dec w named variable?
- is the effect of variable on no similar at all birth masses or no?
If scientists only put largest organisms back in breeding tanks what type of selection is this and why?
They have a tank where random organisms added back. What is the purpose of this tank?
- Directional selection
- One extreme of organisms reproducing
- Act as control
- to show effect of no selection
Does a scientists investigation support use of certain removal tools to remove organisms from habitats?
- does removal reduces mean mass of named organisms (if only large removed)
- is info only from one species
- is there a stats test
Why might a student not use a 1/10 dilution of bacteria to estimate the no. of cells in undiluted culture?
- count unlikely to be accurate
- bc too many cells
Why are bacteria resistant to one type of antibiotic more common than bacteria resistant to another type of antibiotic in farm animals?
- certain antibiotic used more often and in higher doses
- resistant bacteria more likely to survive and reproduce and pass on allele for resistance to more commonly used antibiotic
- higher freq of mutations for resistance to certain antibiotic
- so gene passed on to more bacteria
In recent years farm animals have not been given the antibiotic that many bacteria are resistant to. Why is the percentage of bacteria resistant to this antibiotic remaining constant?
- no selection against this resistant bacteria
Why could the no. of people displaying a certain allele inc rapidly once this allele was selected as advantageous?
- dominant allele
- so expressed when only 1 allele is present
LP is caused by a mutation in DNA. This mutation does not occur in the gene coding for lactase. Suggest how this mutation causes LP.
- mutation in promoter region for the gene
- so lactase gene continues to be transcribes
