TAMU Bio 112 Exam 2 Questions And Well Detailed 100% Explained Answers

characteristics of virus - correct answer very small(nm) acellular (without a cell) obligate (need) intracellular (inside) parasites nucleic acids: either DNA or RNA species and tissue specific (receptor specific) nucleic acids + protein coat (capsid) uncertain origin can infect almost all life morphology of virus - correct answer DNA or RNA (double or single stranded) circular (like bacteria) or linear (like us) protein capsid some have "envelope" 4 shapes of viruses - correct answer filamentous-helical icosahedral enveloped head & tail (are complex) bacteriophage - correct answer phage- infects bacteria dna genome head, tail, tail fibers adenovirus - correct answer be able to label/identify: dna, capsomere, glycoproteins (spikes), capsid infects human respiratory tract (cold) non-enveloped (poliovirus, HPV, hepatitus A) Retrovirus - correct answer ex) HIV be able to label/identify: RNA, capsid, reverse transcriptase, matrix proteins, viral envelope, glycoprotein enveloped reverse transcribe RNA genome into DNA form. RNA genome-- DNA virus genome - correct answer smaller than cells genome dna directs host cell to make new virus copies rna may be directly transcribed or replicated first (rna viruses make more errors, mutate more frequently) Baltimore classification - correct answer genome- DNA, RNA single, double stranded linear, circular nofsegmented vs segmented damaging effects of cell - correct answer when virus replicates in host -lysis (burst open) (naked viruses exit this way) -apoptosis (self-destruction) can also leave the cell by budding - doesn't kill the cell immediately (enveloped viruses by exocytosis) virus infections-steps - correct answer 1. attachment 2. entry 3. replication and assembly 4. egress (release) attachment - correct answer receptors bind to virus capsid proteins or virus envelope glycoproteins -only to R receptor (very specific) entry - correct answer bacteriophage enter "naked" may enter by endocytosis, or if enveloped by fusion naked-endocytosis enveloped-fusion (like dissolve like) replication and assembly - correct answer dna- use host enzyme rna- rna retrovirus- reverse transcription egress - correct answer lysis & death host maybe by budding virus infections- steps summarized - correct answer 1. protein on virus attach to receptor (glycoprotein) on host. specific in shape 2. endocytosis or fusion 3. dna or rna Dna- use host dna & dna polymerase rna- have own enzymes rna retrovirus- reverse transcriptase (rna-- dna) 4. release of progeny (babies/offspring) lysis-naked budding off-enveloped bacteriophages - correct answer virus infect bacteria well studied can carry genes from 1 bacteria to the next double stranded 10^31 SARS-CoV-2 - correct answer enveloped non-segmented positive sense (looks like mrna. goes straight to ribosome and make proteins) single stranded rna virus origin in bats. primary host wuhan, china covid transmission - correct answer respiratory drops propelled droplets surfaces tests for covid - correct answer -diagnostic PCR-amplify nucleic acids molecular- detect genetic material (active) antigen- detect protein on virus surface -antibody past infection look for antibodies (immune response) antibiotics - correct answer target prokaryotic cell structure CANT use to treat viral infections vaccines - correct answer -trigger immune response antibody against virus memory (B cells and T cells) -damaged "live" virus (risk infection) -killed virus -molecular subunits (RNA--protein) lytic - correct answer "normal" pathway attachment, entry, replicate genome, protein transcription (assembly), exit (lysis) lysogenic - correct answer attachment, entry, insert genome into host chromosome, genome copied every time cell divides, conditions get bad, goes into assembly/exit mode. cancer - correct answer incorporating virus into genome can cause cancer. when incorporated into oncogene-cause cancer oncogene - correct answer protein control cell cycle. animal viruses - correct answer fast disease (cold, flu) chronic infection (hep C) (long lasting) intermittent symptoms (herpes, chicken pox) asymptomatic infection oncogenesis plant viruses - correct answer 1. horz transmission enters damaged tissue 2. vert transmission from parent plant hypoplasia (decreased growth) necrosis measles and ro - correct answer MMR vaccine- measles, mumps, rubella measles- deadly mumps- young boys sterile rubella- miscarriage, deformities Ro (R naught) - correct answer # of people a person with disease infects. Ro1, cases drop SARS- 1.3 & 2.3 measles- 15 or 16 antivirals - correct answer fusion inhibitors- keep from attaching to the receptor reverse transcriptase inhibitor- retrovirus (RNA does not go to DNA) integrase inhibitors- DNA & retroviruses. block virus get into DNA protease inhibitors- viruses are often 1 long protein. use protease cut into smaller pieces. prions - correct answer protein gone bad. misfiled protein causes other proteins like it to misfold very small no nucleic acid fatal nerogenic disease viroids - correct answer small circles of rna only known infect plants replicate in cell don't make proteins cause crop failure prokaryotic structure (bacteria) - correct answer very small (bigger than virus, smaller than eukaryote) no membrane bound nucleus no membrane bound organelles 3 shapes: bacillus (rod), cocci (spheres), spiral unicellular almost all cell wall except mycoplasma gram + - correct answer purple thick cell wall (peptidoglycan) gram - - correct answer pink thin cell wall outer membrane 2 periplasmic spaces penicillin - correct answer inhibits synthesis of peptidoglycan (inhibits enzyme) capsule or slime layer of bacteria - correct answer sticky carb and protein outside cell wall glues cells together resist attacks from immune system holds in moisture hairlike fimbriae - correct answer stick to surface and each other movement (bacteria) - correct answer taxis: move to or away from stimu