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BIO |! 235 |! Exam |! 2 |! with |! precise |!
detailed |! solutions
Independent |! assortment |! - |! Correct |! answer |! ✔Genes |! assort |! independently |! of |! each |! other |! when |! they |! are |! on |! opposite |! chromosomes Linkage |! - |! Correct |! answer |! ✔Two |! genes |! on |! a |! single |! pair |! of |! homologs; |! exchange |! occurs |! between |! two |! non-sister |! chromatids Chiasmata |! - |! Correct |! answer |! ✔Location |! of |! exchange |! of |! information |! between |! chromatids when |! does |! crossing |! over |! occur? |! - |! Correct |! answer |! ✔prophase |! I |! of |! meiosis How |! often |! does |! recombination |! occur? |! - |! Correct |! answer |! ✔Very |! frequently What |! determines |! how |! often |! genes |! will |! cross |! over? |! - |! Correct |! answer |! ✔Their |! distance |! from |! one |! another. |! The |! closer |! they |! are, |! the |! less |! likely |! they |! are |! to |! cross |! over. What |! does |! it |! mean |! when |! genes |! are |! linked? |! - |! Correct |! answer |! ✔they |! are |! on |! the |! same |! chromosome; |! assort |! independently
Describe |! how |! geneticists |! detect |! linkage |! of |! a |! gene |! - |! Correct |! answer |! ✔1. |! Select |! true-breeding |! lines |! that |! are |! homozygous |! dominant |! for |! one |! trait |! & |! homozygous |! recessive |! for |! the |! other |! trait |! (ygr |! ANL |! / |! ygr |! ANL |! & |! YGR |! anl |! / |! YGR |! anl). |! Parents |! produce |! dihybrid |! F1 |! population |! (ygr |! ANL |! / |! YGR |! anl)
- |! Cross |! the |! F1 |! dihybrid |! with |! a |! homozygous |! recessive |! (ygr |! anl |! / |! ygr |! anl). |! This |! will |! result |! in |! an |! F2 |! pop. |! where |! the |! dihybrid |! traits |! segregate.
- |! Cross |! each |! F2 |! individual |! with |! a |! homozygous |! recessive How |! do |! you |! determine |! if |! the |! genes |! are |! linked |! or |! not |! after |! performing |! a |! test |! cross? |! - |! Correct |! answer |! ✔If |! the |! ratio |! is |! 1:1:1:1, |! they |! assort |! independently |! and |! are |! unlinked If |! the |! ratio |! for |! the |! recombinant |! class |! is |! less |! than |! the |! parental |! class, |! you |! know |! they |! do |! not |! assort |! independently |! and |! are |! linked Parental |! class |! - |! Correct |! answer |! ✔original |! arrangement |! of |! alleles |! on |! the |! two |! chromosomes |! (no |! recombination); |! came |! from |! meiosis |! unchanged Recombinant |! class |! - |! Correct |! answer |! ✔does |! not |! have |! chromosomes |! passed |! from |! parents How |! is |! distance |! between |! genes |! found? |! - |! Correct |! answer |! ✔The |! farther |! apart |! two |! genes |! are |! located |! on |! a |! chromosome, |! the |! higher |! the |! probability |! that |! a |! recombinant |! event |! takes |! place |! between |! them Recombinant |! frequency |! (RF) |! - |! Correct |! answer |! ✔percentage |! of |! the |! total |! progeny |! that |! are |! recombinant |! type
Phenotypic |! marker |! - |! Correct |! answer |! ✔mark |! of |! position |! on |! chromosome |! that |! allows |! you |! to |! create |! a |! map |! of |! the |! chromosome How |! are |! phenotypic |! markers |! similar |! to |! highway |! markers? |! - |! Correct |! answer |! ✔They |! don't |! change |! or |! do |! anything, |! they |! just |! help |! you |! know |! where |! you |! are |! at How |! can |! you |! calculate |! the |! frequency |! of |! double |! crossover |! (DCO) |! events? |! - |! Correct |! answer |! ✔product |! rule If |! the |! frequency |! of |! a |! single |! crossover |! between |! A |! and |! B |! is |! 12%, |! the |! frequency |! for |! B |! and |! C |! is |! 18%, |! what |! is |! the |! frequency |! of |! a |! double |! crossover |! between |! A |! and |! C? |! - |! Correct |! answer |! ✔0.18*0.12 |! = |! 0. 21.6% Chromosomal |! Interference |! - |! Correct |! answer |! ✔Crossovers |! do |! not |! occur |! independently Crossover |! between |! A |! and |! B |! decreases |! the |! chance |! of |! a |! crossover |! between |! B |! and |! C How |! do |! you |! calculate |! interference? |! - |! Correct |! answer |! ✔Observed |! frequency |! of |! DCO |! divided |! by |! Expected |! frequency |! of |! DCO |! is |! equal |! to |! coefficient |! of |! coincidence |! (0.52/0.79 |! = |! 0.66) Interference |! = |! 1 |! - |! coefficient |! of |! coincidence |! (1 |! - |! 0.66 |! = |! 0.34)
Deletion |! - |! Correct |! answer |! ✔Loss |! of |! a |! chromosomal |! agent Duplication |! - |! Correct |! answer |! ✔repetition |! of |! a |! chromosomal |! segment ectopic |! recombination |! - |! Correct |! answer |! ✔recombination |! between |! two |! DNA |! sequences |! at |! different |! genomic |! locations. Inversion |! - |! Correct |! answer |! ✔Change |! in |! the |! direction |! of |! part |! of |! the |! genetic |! material |! along |! a |! single |! chromosome |! (AGCCAG |! -> |! GACCGA) Translocation |! - |! Correct |! answer |! ✔Segment |! of |! one |! chromosome |! becomes |! attached |! to |! a |! different |! chromosome Simple |! translocation |! - |! Correct |! answer |! ✔one-way |! transfer; |! piece |! of |! chromosome |! is |! attached |! to |! another |! chromosome Reciprocal |! translocation |! - |! Correct |! answer |! ✔two-way |! transfer; |! two |! different |! types |! of |! chromosomes |! exchange |! pieces, |! producing |! two |! abnormal |! chromosomes |! w/ |! translocations Deletion |! loop |! - |! Correct |! answer |! ✔the |! loop |! formed |! at |! meiosis |! by |! the |! pairing |! of |! a |! normal |! chromosome |! and |! a |! deletion-containing |! chromosome
Results |! in |! two |! normal |! chromosomes, |! one |! with |! two |! centromeres, |! and |! one |! with |! no |! centromeres What |! happens |! to |! the |! two |! abnormal |! chromosomes |! from |! pericentric |! inversion? |! - |! Correct |! answer |! ✔The |! chromosome |! with |! no |! centromere |! will |! be |! lost |! bc |! the |! spindle |! fibers |! have |! nothing |! to |! grab |! hold |! of The |! chromosome |! with |! 2 |! centromeres |! will |! break |! because |! one |! spindle |! fiber |! will |! grab |! it |! from |! one |! end |! and |! another |! from |! the |! opposite |! end, |! playing |! tug |! of |! war What |! happens |! when |! inverted |! chromosomes |! crossover? |! - |! Correct |! answer |! ✔They |! do |! not |! crossover |! equally, |! leaving |! one |! part |! of |! the |! chromosome |! without |! a |! centromere. |! That |! chromosome |! is |! lost |! bc |! it |! has |! no |! centromere. Dicentric |! chromosomes |! lead |! to |! dicentric |! bridges dicentric |! bridge |! - |! Correct |! answer |! ✔Structure |! produced |! when |! the |! two |! centromeres |! of |! a |! dicentric |! chromatid |! are |! pulled |! toward |! opposite |! poles, |! stretching |! the |! dicentric |! chromosome |! across |! the |! center |! of |! the |! nucleus. |! Eventually, |! the |! dicentric |! bridge |! breaks |! as |! the |! two |! centromeres |! are |! pulled |! apart. What |! causes |! Familial |! Down-Syndrome? |! - |! Correct |! answer |! ✔Translocation |! of |! q |! are |! of |! chromosome |! 21 |! (q-) |! is |! translocated |! to |! chromosome |! 10 |! or |! 14 |! (q+). |! This |! causes |! there |! to |! be |! three |! ends |! of |! chromosome |! 21, |! which |! heavily |! affects |! gene |! dosage. Translocation |! carrier |! - |! Correct |! answer |! ✔Individual |! organism |! heterozygous |! for |! a |! chromosome |! translocation
metacentric |! chromosome |! - |! Correct |! answer |! ✔Chromosome |! in |! which |! the |! two |! chromosome |! arms |! are |! approximately |! the |! same |! length, |! which |! leaves |! one |! fragmented |! chromosome. |! Person |! can |! live |! without |! fragment. What |! happens |! to |! translocated |! chromosomes |! when |! they |! find |! their |! homologous |! pair? |! - |! Correct |! answer |! ✔They |! form |! cross-like |! structures |! in |! order |! to |! line |! up |! correctly. It |! causes |! infertility |! 50% |! of |! the |! time; |! it |! depends |! how |! the |! chromosomes |! line |! up |! during |! metaphase Fragile |! X |! Syndrome |! - |! Correct |! answer |! ✔A |! genetic |! disorder |! involving |! an |! abnormality |! in |! the |! X |! chromosome, |! which |! becomes |! constricted |! and |! often |! breaks. If |! have |! just |! a |! few |! repeats, |! the |! effects |! are |! not |! bad |! but |! become |! worse |! as |! the |! number |! of |! repeats |! increases trinucleotide |! repeats |! - |! Correct |! answer |! ✔a |! form |! of |! mutation |! associated |! with |! the |! expansion |! in |! copy |! number |! of |! a |! nucleotide |! triplet |! in |! or |! near |! a |! gene How |! do |! numbers |! of |! triunucleotide |! repeats |! affect |! people? |! - |! Correct |! answer |! ✔<50 |! - |! unaffected 55-230 |! - |! pre-mutation
230 |! disease |! causing
Primary |! Down |! Syndrome |! - |! Correct |! answer |! ✔Caused |! by |! the |! failure |! of |! chromosome |! 21 |! to |! segregate |! properly |! (nondisjunction) Nondisjuction |! - |! Correct |! answer |! ✔the |! failure |! of |! one |! or |! more |! pairs |! of |! homologous |! chromosomes |! or |! sister |! chromatids |! to |! separate |! normally |! during |! nuclear |! division, |! usually |! resulting |! in |! an |! abnormal |! distribution |! of |! chromosomes |! in |! the |! daughter |! nuclei |! (down |! syndrome) Are |! autosomal |! conditions |! more |! severe |! than |! sex |! chromosome |! conditions? |! - |! Correct |! answer |! ✔Yes |! bc |! the |! extra |! X |! chromosomes |! are |! made |! nonfunctional Autosomes |! carry |! hundreds |! of |! genes Are |! monosomies |! lethal? |! - |! Correct |! answer |! ✔Yes, |! very Autopolyploidy |! - |! Correct |! answer |! ✔a |! type |! of |! euploidy |! wherein |! the |! additional |! set |! of |! chromosomes |! is |! derived |! from |! a |! parent |! or |! identical |! parental |! species Allopolyploidy |! - |! Correct |! answer |! ✔chromosome |! sets |! are |! from |! two |! or |! more |! species amphidiploid |! - |! Correct |! answer |! ✔contains |! diploid |! sets |! of |! chromosomes |! from |! two |! different |! species Endopolyploidy |! - |! Correct |! answer |! ✔certain |! body |! tissues |! display |! normal |! variations |! in |! the |! number |! of |! sets |! of |! chromosomes
diploid |! animals |! sometimes |! produce |! tissues |! that |! are |! polyploid What |! generates |! autopoplyploids? |! - |! Correct |! answer |! ✔complete |! mitotic |! nondisjunction |! in |! mitosis Complete |! mitotic |! nondisjunction |! - |! Correct |! answer |! ✔sister |! chromatids |! separate, |! but |! will |! not |! be |! pulled |! in |! separate |! daughter |! nuclei, |! they |! end |! up |! in |! the |! same |! nucleus |! as |! independent |! chromosomes 4n What |! is |! the |! purpose |! of |! colchicine? |! - |! Correct |! answer |! ✔Causes |! failure |! of |! anaphase |! by |! blocking |! activity |! of |! spindle |! fibers, |! causing |! complete |! nondisjunction Used |! in |! plants |! to |! increase |! gene |! expression Triploids |! - |! Correct |! answer |! ✔Having |! three |! complete |! sets |! of |! chromosomes comes |! from |! one |! diploid |! gamete |! & |! one |! haploid |! gamete Are |! polyploids |! sterile |! or |! not? |! - |! Correct |! answer |! ✔Sterile |! bc |! odd |! number |! of |! chromosome |! sets |! produce |! unbalanced |! gametes, |! which |! leads |! to |! imbalance |! of |! gene |! dosage Why |! are |! allodiploids/allopolyploids |! infertile? |! - |! Correct |! answer |! ✔When |! distantly |! related |! species |! produce |! offspring, |! many |! or |! all |! of |! their |! chromosomes |! fail |! to |! find |! a |! homologue |! or |! segregate |! properly |! and |! produce |! unbalanced |! gametes
What |! composes |! the |! bacterial |! genome? |! - |! Correct |! answer |! ✔one |! or |! more |! circular |! chromosome |! & |! one |! or |! more |! plasmids Transformation |! - |! Correct |! answer |! ✔when |! bacterial |! cell |! dies, |! DNA |! is |! released |! from |! cell, |! & |! another |! cell |! picks |! it |! up |! & |! takes |! it |! as |! its |! own Conjugation |! - |! Correct |! answer |! ✔only |! for |! plasmids donor |! cell |! establishes |! bridge, |! passes |! one |! strand |! of |! plasmid |! DNA |! to |! the |! recipient |! cell Transduction |! - |! Correct |! answer |! ✔viruses |! (phages) when |! phage |! infects |! bacterial |! cell, |! it |! kills |! that |! cell |! & |! the |! created |! phages |! infect |! other |! cells, |! passing |! on |! original |! cell's |! DNA Plasmid |! - |! Correct |! answer |! ✔a |! small |! ring |! of |! DNA |! that |! carries |! accessory |! genes |! separate |! from |! those |! of |! the |! bacterial |! chromosome replicates |! independently Are |! plasmids |! essential? |! - |! Correct |! answer |! ✔no |! but |! they |! do |! provide |! advantages |! for |! the |! cell |! such |! as |! the |! ability |! to |! make |! hosts |! sick F |! factor |! (fertility |! factor) |! - |! Correct |! answer |! ✔conjugative |! plasmid |! transferred |! from |! cell |! to |! cell |! by |! conjugation is |! an |! episome low |! copy |! number |! plasmid |! in |! length
Episome |! - |! Correct |! answer |! ✔a |! genetic |! element |! that |! can |! exist |! either |! as |! a |! plasmid |! or |! as |! part |! of |! the |! bacterial |! chromosome Describe |! the |! process |! of |! conjugation |! and |! the |! F |! factor |! - |! Correct |! answer |! ✔F+ |! cells |! use |! appendages |! called |! pili |! to |! find |! a |! F- |! cell. |! When |! they |! do, |! they |! form |! a |! bridge |! between |! the |! cells. |! A |! single |! strand |! of |! the |! DNA |! from |! the |! F+ |! cell |! will |! go |! across |! the |! bridge |! into |! the |! F- |! cell. Hfr |! cell |! - |! Correct |! answer |! ✔a |! cell |! with |! the |! F |! plasmid |! integrated |! into |! the |! chromosome How |! is |! transfer |! of |! Hfr |! different |! than |! F? |! - |! Correct |! answer |! ✔Since |! the |! F |! factor |! in |! Hfr |! is |! integrated |! into |! the |! chromosomes, |! the |! recipient |! cell |! receives |! some |! of |! the |! DNA |! from |! the |! chromosome Describe |! the |! process |! of |! Hfr |! transfer |! from |! one |! cell |! to |! another |! - |! Correct |! answer |! ✔A |! cell |! with |! integrated |! F |! in |! Hfr |! will |! find |! an |! F- |! cell |! and |! form |! a |! bridge |! between |! them. |! The |! Hfr |! cell |! will |! begin |! a |! rolling-circle |! replication |! process |! starting |! at |! the |! Hfr, |! sending |! one |! strand |! to |! the |! F- |! cell |! similar |! to |! unwinding |! tape. |! The |! Hfr |! cell |! will |! begin |! to |! replicate |! and |! the |! transferred |! strand |! will |! also |! replicate |! until |! it |! is |! done |! and |! will |! separate. |! The |! newly |! acquired |! chromosome |! fragment |! will |! find |! its |! homologous |! pair |! and |! crossover, |! leaving |! the |! Hfr |! and |! part |! of |! the |! donor |! cell's |! DNA |! in |! the |! F- |! cell. |! Recipient |! cell |! remains |! F-. interrupted |! mating |! technique |! - |! Correct |! answer |! ✔Hfr |! and |! F- |! strains |! were |! incubated, |! and |! samples |! were |! removed |! at |! various |! intervals |! and |! placed |! in |! a |!
Virulent |! phages |! - |! Correct |! answer |! ✔reproduce |! strictly |! through |! the |! lytic |! cycle |! and |! always |! kill |! their |! host |! cells Temperate |! phages |! - |! Correct |! answer |! ✔phages |! that |! use |! both |! the |! lytic |! and |! lysogenic |! cycles Generalized |! transducing |! phage |! p1 |! - |! Correct |! answer |! ✔cuts |! bacterial |! chromosome |! into |! pieces |! and |! can |! package |! bacterial |! DNA |! into |! phage |! particles generalized |! transducing |! phage |! - |! Correct |! answer |! ✔transfers |! DNA |! derived |! from |! any |! part |! of |! the |! bacterial |! chromosome specialized |! transducing |! phage |! - |! Correct |! answer |! ✔transfers |! genes |! from |! a |! particular |! region |! of |! the |! bacterial |! chromosome contransduction |! - |! Correct |! answer |! ✔probability |! of |! two |! markers |! being |! transduced |! simultaneously Natural |! transformation |! - |! Correct |! answer |! ✔DNA |! uptake |! occurs |! without |! outside |! help artificial |! transformation |! - |! Correct |! answer |! ✔DNA |! uptake |! occurs |! with |! the |! help |! of |! special |! techniques
Retroviruses |! - |! Correct |! answer |! ✔use |! reverse |! transcriptase |! to |! copy |! their |! RNA |! genome |! into |! host |! genome |! (HIV, |! SIV) RNA |! to |! RNA |! - |! Correct |! answer |! ✔replication |! of |! RNA |! viruses |! (COVID-19) RNA-dependent |! & |! RNA |! polymerase DNA |! to |! DNA |! - |! Correct |! answer |! ✔chromosomal |! replication DNA-dependent |! & |! DNA |! polymerase DNA |! to |! RNA |! - |! Correct |! answer |! ✔gene |! transcription DNA-dependent |! & |! RNA |! polymerase |! (most |! common) RNA |! to |! DNA |! - |! Correct |! answer |! ✔retroviral |! insertion |! in |! genome RNA-dependent |! & |! DNA |! polymerase Structure |! of |! retrovirus |! - |! Correct |! answer |! ✔Viral |! protein |! coat |! (capsid) |! - |! houses |! two |! copies |! of |! RNA |! genome |! and |! reverse |! transcriptase |! enzyme Core-shell |! proteins |! - |! surrounds |! capsid Viral-envelope |! glycoprotein |! - |! has |! important |! proteins |! that |! must |! recognize |! certain |! receptors |! in |! cells infection |! cycle |! of |! retrovirus |! - |! Correct |! answer |! ✔1. |! virus |! attaches |! to |! host |! cell |! at |! receptors |! in |! the |! membrane
- |! viral |! core |! enters |! host |! cell
