ap bio long essays unit 3

8c. predict DNA point mutation that will result in methionine-to-valine substitution

A --> G

7a. describe steps involved in synthesis of this polypeptide (translation)

- translation - process of making polypeptides using mRNA as a template - mRNA is read in codons, which are sets of 3 nitrogen bases that code for a specific amino acid - tRNA carries anticodons, which are sets of 3 bases complementary to mRNA's codons - translocation - process of mRNA moving along ribosome & poplypeptide is made

4b. propose improvement of environmental factor and explain how it will affect experiment

- keep constant temperature - different temperature affect flies' activity - more active at higher temperatures = need more glucose for cellular respiration

5c. identify and discuss 2 different factors that would affect whether the island's fly population is in Hardy-Weinberg equilibrium for the traits above.

- no mutation - no new alleles in population - no natural selection - no alleles favored or disfavored by environment

10c. select specific virus and explain how it deviates from central dogma

- HIV - rna to dna

4c. perform a chi-square test on data for 10-min time point in banana experiment. specify null hypothesis

null hypothesis: the flies will be evenly distributed across the 3 parts of the chamber chi-square = (o-e)^2/e

8b. calculate minimum number of nucleotides to produce & terminate 565-amino acid polypeptide. provide 2 reasons nucleotides in mature mRNA may differ from base pairs in gene.

565x3= 1695+3+3=1701 - 3 nucleotides=codon=amino acid - 3 nucleotides for start codon - 3 nucleotides for stop codon - introns are removed from mRNA but remain in gene structure - alternative splicing mixes different exons

10a. explain role of

rna polymerase- enzyme that uses DNA as template to make RNA spliceosomes- removes introns and connect exons in RNA codons - groups of three that code for amino acids ribosomes - made up of RNA and proteins and is site of protein synthesis tRNA - transports amino acids during translation

11a. describe role of the following

rna splicing - spliceosomes remove introns and splice together exons methylation - methyle groups are added to DNA, causing tight coiling & decreased gene expression siRNA - RNA molecules that binds to mRNA

5a. what conclusions can be drawn from cross 1 and cross 2? explain how data supports conclusions

- bronze is dominant b/c all F1 offspring had bronze eyes - the trait is autosomal/non sex-linked b/c equal distribution of F2 phenotypes for both genders

4d. explain whether hypothesis is supported by chi-squared test & justify explanation

- degrees of freedom is 2 - critical value is 5.99 - hypothesis rejected b/c chi-squared value is greater than critical value

7b. explain effect of deletion or addition in one nuceotide

- deletion will result in frameshift mutation - all codons after mutation will change, amino acids change - if deletion occurs in start codon, translation could be inhibited - if deletion occurs in stop codon, translation could stop in wrong place - deletion could create stop codon, stop prematurely

10b. discuss 3 specific mechanisms of protein regulation in eukaryotic cells

- dna methylation - methyl groups added to DNA, causes tight coiling & decreases gene expression - histone acetylation - acetyl groups added to histone proteins, causing less coiling & increases gen expression - alternative rna splicing - different mRNA molecules are produced from same pre-mRNA

5b. what conclusions can be drawn from cross 3? explain how data your conclusions

- genes are linked - the genes are not a 1:1:1:1 ratio as predicted by independent assortment

4e. briefly propose model that describes how environmental cues affect behavior of flies in the choice chamber

- glucose is the stimulus - fruit flies move towards glucose as a response

4a. predict distribution of flies in chamber after 10 minutes & justify answer

- more flies in chamber w/ glucose soaked cotton ball - glucose is an energy source for fruit flies = more attracted to it

7c. explain effect of substitution in one nucleotide

- most substitutions alter only one amino acid - substitution at start or stop, translation doesn't start or end properly - substitution creates stop codon, premature stop - substitution occurs in intron, protein made properly

8d. propose 3 features of model to connect genetic mutation you predicted with activity of signal pathway

- mutation causes structural change in protein, which affects shape of receptor and causes loss of function - mutation leads to change in protein, which increases ligands ability to bind to receptor, which increases signaling pathway for protien - mutation leads to overproduction of membrane protein, increasing signaling pathway for protein

8a. describe 2 characteristics of pedigree that would support disorder being autosomal dominant

- occurs equally in males and females - carriers must express loeys-dietz syndrome

4b. propose improvement of experimental control and explain how it will affect experiment

- soak control cotton with water - eliminates moisture content as a variable

7a. describe steps involved in synthesis of this polypeptide (transcription)

- transcription - the process of using DNA as a template to make mRNA - promoter - a segment of DNA where RNA polymerase attaches & initiates transcription RNA polymerase - an enzyme that binds to the DNA & adds nucleotides to growing chain of RNA during transcription - mRNA travels from nucleus to ribosome