Practice questions Flashcards
Name a property of a DNA barcode that makes it ideal for identifying species.
shows a large amount of variation between species
Which of the reactions occurs in the blood clotting process?
A) Fibrinogen is converted to fibrin by the enzyme thromboplastin
B) Prothrombin is converted to thrombin by the enzyme thromboplastin
B) Prothrombin is converted to thrombin by the enzyme thromboplastin
What would be the correct antigens and antibodies for a patient receiving blood from a donor with blood group AB?
A and B antigens on erythrocytes
no antibodies in blood plasma
reason: AB donor matches AB patient blood group
Are neutrophils granulocytes or agranulocytes?
granulocytes
Which part(s) of a RNA nucleotide can form a phosphodiester bond with other nucleotides?
phosphate group and OH of the pentose sugar
Name and describe the 4 key features of the genetic code
degenerate - more than 1 codon for each amino acid
non-overlapping - each one codon/triplet in the sequence is read separately
triplet code - three bases are needed to code for one amino acid
universal - the same in almost all organisms
What feature of the DNA molecule provides stability?
phosphodiester bonds / sugar-phosphate backbone / double helix
Name the membrane which surrounds the vacuole in plant cells.
tonoplast
At a low pH, will a solution be more or less acidic?
How will protons affect proteins and membranes?
more acidic
protons will affect the ionic bonds in proteins and cause them to denature, causing membranes to become more permeable
Describe the inflammatory response
triggered by damaged cells / entry of pathogens
mast cells release histamine causing vasodilation
there is increased blood flow to the area
capillary walls are more permeable, making it easier for phagocytes to leave the blood
Describe how an ultrasound is used to measure the biparietal diameter of a fetus.
handheld transducer emits sound waves into the mother’s body which are then reflected back by the fetus to produce an image of the fetus on a monitor screen
a transducer can be used to provide different angles
the head of the fetus is measured at its widest point for the BPD
Suggest 4 factors that should be taken into account when using a growth chart to estimate the gestational age of a fetus
gender
maternal lifestyle
genetics
if a twin, the fetus could be smaller
During _ of meiosis 1, homologous chromosomes begin to pair up to form a bivalent.
prophase
During meiosis 1, alignment on the equator of the spindle and separation of the chromosomes in each pair to opposite poles of the cell is random. This process is called _.
independent assortment
Explain the term PEFR.
peak expiratory flow rate = the maximum rate at which air is forcibly exhaled
Explain the term FEV1
forced expiratory volume in one second = the volume of air that can be breathed out in the first second of forced exhalation
If FEV1 is lower than expected, this could be…?
a respiratory problem (airways reduced or restricted)
How must expired air resuscitation differ when being carried out on a child (3 ways)?
smaller puffs of air expired
head not tilted back as far
cover the mouth and nose of the child
Name the key advantage of a live-attenuated vaccine?
gives the strongest immune response and long lasting immunity
Name the 3 key advantages of killed inactivated pathogens?
safer / more stable than live vaccines
do not require refrigeration
can be given to patients with weakened immune systems
If the anticodon of the tRNA molecule specific to the amino acid phenylalanine (phe) is AAG. Which of the following statements is correct?
A) the triplet on the template strand that codes for phe is AAG
B) the triplet on the sense strand that codes for phe is AAG
C) the triplet on the template strand that codes for phe is TTC
D) the triplet on the sense strand that codes for phe is UUG
A) the triplet on the template strand that codes for phe is AAG
reasoning: template (antisense) strand = template for transcription with complementary bases to mRNA and the DNA sense strand
sense strand = same base sequence as RNA (T replaced with U in mRNA)
the anticodon of the tRNA has the same base sequence as the template strand (but uses U)
template strand bases = tRNA bases
sense strand bases = mRNA bases
Which of the following statements about fossil evidence does not support the conclusion that hominids were bipedal?
A) Hominids have a large cranial capacity
B) Hominid vertebral columns have a double curve
C) Hominid feet are arched
D) Hominid thigh bones slope inward from hip to knee
A) Hominids have a large cranial capacity
reason: bipedal = using only two legs for walking
What is cell x if it is a leucocyte and can differentiate to become a plasma cell?
B lymphocyte
Where are antibodies synthesised?
on the RER
How are the 4 polypeptide chains of an antibody molecule held together?
by disulfide bonds
Many bananas in shops are triploid. Which stage of the cell cycle would they be unable to complete? A) cytokinesis B) mitosis C) meiosis D) S phase
C) meiosis
reason: meiosis only occurs in gamete formation
A 40yr old man has measured blood pressure of 170/105mm Hg. Which of the following best describes the interpretation of this reading? A) high normal B) hypertension requiring treatment C) hypotension D) mild hypertension
B) hypertension requiring treatment
reason: 140/90mm Hg and above requires treatment
What type of bonds can the R group of an amino acid form in the tertiary structure of a protein?
hydrogen bonds
In people with a patent foramen ovale (PFO), there is a small gap in the atrial septum allowing some blood to pass between the atria. Explain why the circulatory system of a person with PFO may not be considered a double circulatory system.
Not all blood will pass through the heart twice in 1 circuit.
Some blood will not pass through pulmonary circulation.