PLTW - MEDICAL INTERVENTIONS FINAL
COMPREHENSIVE STUDY GUIDE 2026 FULL QUESTIONS
AND SOLUTIONS GRADED A+
● What is the difference between gram (+) bacteria and gram (-) bacteria?. Answer: Gram (+)
bacteria have a thick peptidoglycan wall and a cell membrane. Gram (-) bacteria have a thin
peptidoglycan wall, a cell membrane, and are covered with lipopolysaccharides and proteins.
● What does a BLAST analysis do?. Answer: BLAST compares the DNA sequences input
into it to its large database
● What does the ELISA test do and what does it stand for?. Answer: ELISA-
Enzyme-linked-immunosorbant-assay This is a test that takes advantage of some of the
body's natural immune responses to identify the presence of illness.
● What is an antigen?. Answer: An antigen is really a type of protein found on the outside of
every living cell (and virus!). Antigens are surface markers that cells use to identify each other.
It's how your body knows that your body cells are truly yours, and they are how your body
identifies cells and viruses that aren't yours.
● What is an antibody?. Answer: The job of antibodies is to attach to foreign antigens. By
attaching, those foreign antigens are neutralized. That attachment also signals other types of
leukocytes (T lymphocytes) to come in and destroy whatever the antibody is attached to. So,
antibodies attach to antigens. That is the principle behind an ELISA.
● What are the symptoms of meningitis?. Answer: Fever; stiff neck; severe headache;
vomiting or nausea with headache; confusion or difficulty concentrating; sensitivity to light;
seizures; fatigue/difficulty waking up; loss of appetite; skin rashes (in some cases)
● What are β-Lactam Antibiotics and what is an example?. Answer: Irreversibly inhibit
enzymes involved in the final steps of cell wall synthesis. The enzymes inhibited by these
drugs mediate the formation of the peptide bridges between adjacent strands of
peptidoglycan. These drugs vary in their spectrum of activity; some are more active against
Gram positive bacteria; whereas, others are more active against Gram negative bacteria;
example, Penicillin
● What are tetracyclines and what is an example?. Answer: Reversibly bind to the 30S
ribosomal subunit, blocking the attachment of tRNA to the ribosome and preventing the
, continuation of protein synthesis. They are effective against certain Gram positive and Gram
negative bacteria; example, Doxycycline
● What are sulfonamides and what is an example?. Answer: Inhibit the growth of many Gram
positive and Gram negative bacteria. They are structurally similar to paraminobenzoic acid
(PABA), a substrate in the pathway for folic acid biosynthesis. Because of this similarity, the
enzyme that normally binds with PABA preferentially binds with the sulfonamide drugs,
resulting in its competitive inhibition. Human cells are not affected by these drugs because
they lack this enzyme; example, Sulfadiazine
● What are fluoroquinolones and what is an example?. Answer: Inhibit one or more of a group
of enzymes called topoisomerases, which maintain the supercoiling of the chromosomal DNA
within the bacterial cells. The inhibition of these enzymes prevents essential cell processes.
The fluoroquinolones are active against a wide variety of bacteria, including both Gram
positive and Gram negative bacteria; example, Ciprofloxacin
● Starting from the outer ear, trace the pathway of structures to the inner ear.. Answer: 1)
Pinna (outer ear), 2) external auditory meatus, 3) tempanic membrane (eardrum), 4) ossicles
(malleus, incus, stapes), 4) tympanic cavity, 5) eustachian tube, 5) semicircular canals, 6)
cochlea, 7) vestibular nerve, 8) facial nerve, 9) cochlear nerve, 10) Internal auditory meatus
● Does a higher frequency show a higher or lower pitch?. Answer: Higher pitch
● Conductive vs. sensorineural hearing loss?. Answer: Conductive hearing loss - hearing loss
of the outer ear; sensorineural hearing loss - hearing loss of the inner ear
● What are the three steps of PCR?. Answer: 1) Denaturation 2) Annealing 3) Exension
● What is the difference between amniocentesis and chorionic villi sampling?. Answer:
Amniocentesis involves inserting a large needle through the abdomen and into the uterus,
where amniotic fluid (the fluid surrounding and protecting the baby) is removed. This fluid
contains cells shed from the baby: skin cells, cells from the lining of the small intestine, or cells
from the bladder. The cells in this fluid provide the DNA needed to perform genetic testing.
Chorionic villus sampling, on the other hand, can be done earlier. Here, chorionic villus cells
are removed from the placenta. This is done by inserting a needle vaginally and directing that
needle to the placenta. A small sample of those cells - which are identical to the cells inside
the baby - are removed and used for testing.
● What does an MRI scan stand for? CT scan?. Answer: MRI - Magnetic Resonance Imaging
CT - Computed Tomography scan
● What is the best method for being able to diagnose cancer?. Answer: Biopsy
COMPREHENSIVE STUDY GUIDE 2026 FULL QUESTIONS
AND SOLUTIONS GRADED A+
● What is the difference between gram (+) bacteria and gram (-) bacteria?. Answer: Gram (+)
bacteria have a thick peptidoglycan wall and a cell membrane. Gram (-) bacteria have a thin
peptidoglycan wall, a cell membrane, and are covered with lipopolysaccharides and proteins.
● What does a BLAST analysis do?. Answer: BLAST compares the DNA sequences input
into it to its large database
● What does the ELISA test do and what does it stand for?. Answer: ELISA-
Enzyme-linked-immunosorbant-assay This is a test that takes advantage of some of the
body's natural immune responses to identify the presence of illness.
● What is an antigen?. Answer: An antigen is really a type of protein found on the outside of
every living cell (and virus!). Antigens are surface markers that cells use to identify each other.
It's how your body knows that your body cells are truly yours, and they are how your body
identifies cells and viruses that aren't yours.
● What is an antibody?. Answer: The job of antibodies is to attach to foreign antigens. By
attaching, those foreign antigens are neutralized. That attachment also signals other types of
leukocytes (T lymphocytes) to come in and destroy whatever the antibody is attached to. So,
antibodies attach to antigens. That is the principle behind an ELISA.
● What are the symptoms of meningitis?. Answer: Fever; stiff neck; severe headache;
vomiting or nausea with headache; confusion or difficulty concentrating; sensitivity to light;
seizures; fatigue/difficulty waking up; loss of appetite; skin rashes (in some cases)
● What are β-Lactam Antibiotics and what is an example?. Answer: Irreversibly inhibit
enzymes involved in the final steps of cell wall synthesis. The enzymes inhibited by these
drugs mediate the formation of the peptide bridges between adjacent strands of
peptidoglycan. These drugs vary in their spectrum of activity; some are more active against
Gram positive bacteria; whereas, others are more active against Gram negative bacteria;
example, Penicillin
● What are tetracyclines and what is an example?. Answer: Reversibly bind to the 30S
ribosomal subunit, blocking the attachment of tRNA to the ribosome and preventing the
, continuation of protein synthesis. They are effective against certain Gram positive and Gram
negative bacteria; example, Doxycycline
● What are sulfonamides and what is an example?. Answer: Inhibit the growth of many Gram
positive and Gram negative bacteria. They are structurally similar to paraminobenzoic acid
(PABA), a substrate in the pathway for folic acid biosynthesis. Because of this similarity, the
enzyme that normally binds with PABA preferentially binds with the sulfonamide drugs,
resulting in its competitive inhibition. Human cells are not affected by these drugs because
they lack this enzyme; example, Sulfadiazine
● What are fluoroquinolones and what is an example?. Answer: Inhibit one or more of a group
of enzymes called topoisomerases, which maintain the supercoiling of the chromosomal DNA
within the bacterial cells. The inhibition of these enzymes prevents essential cell processes.
The fluoroquinolones are active against a wide variety of bacteria, including both Gram
positive and Gram negative bacteria; example, Ciprofloxacin
● Starting from the outer ear, trace the pathway of structures to the inner ear.. Answer: 1)
Pinna (outer ear), 2) external auditory meatus, 3) tempanic membrane (eardrum), 4) ossicles
(malleus, incus, stapes), 4) tympanic cavity, 5) eustachian tube, 5) semicircular canals, 6)
cochlea, 7) vestibular nerve, 8) facial nerve, 9) cochlear nerve, 10) Internal auditory meatus
● Does a higher frequency show a higher or lower pitch?. Answer: Higher pitch
● Conductive vs. sensorineural hearing loss?. Answer: Conductive hearing loss - hearing loss
of the outer ear; sensorineural hearing loss - hearing loss of the inner ear
● What are the three steps of PCR?. Answer: 1) Denaturation 2) Annealing 3) Exension
● What is the difference between amniocentesis and chorionic villi sampling?. Answer:
Amniocentesis involves inserting a large needle through the abdomen and into the uterus,
where amniotic fluid (the fluid surrounding and protecting the baby) is removed. This fluid
contains cells shed from the baby: skin cells, cells from the lining of the small intestine, or cells
from the bladder. The cells in this fluid provide the DNA needed to perform genetic testing.
Chorionic villus sampling, on the other hand, can be done earlier. Here, chorionic villus cells
are removed from the placenta. This is done by inserting a needle vaginally and directing that
needle to the placenta. A small sample of those cells - which are identical to the cells inside
the baby - are removed and used for testing.
● What does an MRI scan stand for? CT scan?. Answer: MRI - Magnetic Resonance Imaging
CT - Computed Tomography scan
● What is the best method for being able to diagnose cancer?. Answer: Biopsy
