A patient goes into an MRI for a suspected bowel tumour, what planes of the body are being scanned?
Transverse, Sagittal and Coronal
(Content from Week 2)
What are the different stages of the cell cycle and give a brief description in what occurs in each stage?
Interphase - Cell prepares for replication
Prophase - Chromosomes condesnse, centrioles move to opposite poles
Prometaphase - Nuclear envelope dissolves
Metaphase - Chromosomes line up at center of cell
Anaphase - Chromosomes split and go to either ends of the cell
Telophase - Nuclear envelope reforms around chromosome, cytoplasm divides
Cytokinesis - Cells split
Cynthia James has fallen pregnant. Her husband James is ecstatic about the news. In which 3 ways has genetic diversity occurred in this scenario and at what time/phase does it occur in?
Crossing Over - Prophase 1, physical exchange of DNA between 2 homologous chromosomes
Independent Assortment - Orientation of chromosomes at metaphase
Parents are not related
Give 5 differences between eukaryotes and prokaryotes.
Prokaryote vs Eukaryote
Size - .4-2.0um vs 5-100um diamter
Nucleus - No defined region vs Bound by double membrane, contains DNA
Genetic Material - plasmid or double stranded DNA vs double stranded DNA with histones to form chromosomes
Membrane Bound organelles - Absent vs Present
Endoplasmic reticulum - Absent vs Present
Ribosomes - smaller 70s vs larger 80s
Reproduce - asexually binary fission vs sexual or asexual
Explain the difference between passive and active transport?
Passive processes = no cellular energy (ATP) required, substances moves down their concentration gradients, can be “facilitated” or “not facilitated”
Active processes = energy (ATP) required, always “facilitated”, can be against the concentration gradient
Chase woke up this morning and had a big breakfast. After this he went for his morning run but as he was about to finish he fell on the sidewalk and scraped his knee.
Give 2 feedback loops present in this scenario?
Positive Feedback = Blood clotting
Negative Feedback = Vaso Dilation, Increasing blood glucose levels
What occurs during interphase in the cell cycle and what are the distinct phases?
G1 = Cell growth & preparation of chromosomes for replication
G0 = Quiescent State, cell cycle machinery is dismantled, cells are neither dividing or preparing for division
S = Synthesis of DNA & duplication of the centrosome
G2 = Preparation for Division
What are the two types of Chromatin and describe their structure and function?
Heterochromatin = Tightly packed/condensed DNA, less transcriptionally active, AT-rich
Euchromatin = Lightly pack/relaxed DNA, most active proportion genome, GC-rich
What is the difference between cilia, microvilli and stereocilia? Give a brief description of their function, structure and where they are found.
Cilia - Motile projections from the apical surface, Beat rhythmically to move material (e.g. mucus) along the surface. Found in the upper respiratory tract, Fallopian tube
Microvilli - Non-motile projections from the apical surface, Increase surface area for absorption or secretion, GIT (Small Intestine)
Stereocilia - Long microvilli, Non-motile projections from the apical surface of the cells of the epididymis
Describe the general structure of a neuron.
Soma (perikaryon) Nerve cell body, containing nucleus and organelles, present in distinct locations, CNS - grey matter and PNS - ganglia
Dendrites = Usually many, Receive stimuli and pass to soma
Axon/fibre = Single, transmits impulse away from soma
What are the different macromolecules and their respective subunit?
Protein and Amino Acid
Lipid and Fatty Acid
Carbohydrates and Mono/Polysaccaride
Nucleic Acids and Nucleotide
(Content from Week 2)
Cynthia James is planning for a baby with her husband Sean. She takes a pregnancy test 8 days after their last attempt and it comes back positive. What stage of embryonic development will she have reached and describe the structure of the cell?
The blastocyst would have implanted. Consists of trophoblast cells and inner cell mass.
Explain the difference in activity between cardiac, smooth and skeletal muscle?
Cardiac = Strong, quick, continuous, involuntary contraction
Smooth = Weak, slow, continuous contraction
Skeletal = Strong, quick, discontinuous, voluntary contraction
What are the four types of collagen?
Type I: Most common type. ‘Typical’ collagen comprising thick fibres, often arranged in bundles
Type II: Mainly in cartilage. Fibrils embedded in cartilage ground substance
Type III: Reticular fibres. Small fibres forming networks, support blood vessels, muscle, lymphoid organs, form the reticular lamina of basement membrane
Type IV: Does not form fibres or fibrils. Major component of the basal lamina
What are the 4 types of active transport?
Primary active transport = ions are “pumped” across the membrane, powered by ATP, e.g. Na+ / K+ / ATPase pump
Secondary active transport = depends on ion gradient created by primary active transport, energy stored in ionic gradient used indirectly to drive transport of other solutes
“bulk transport”/vesicular transport
can be against concentration gradient, requires energy, typically “bulk” movement of substances
Endocytosis = phagocytosis, pinocytosis, receptor-mediated
Exocytosis = vesicular trafficking
What properties makes water the universal solvent?
Maintains body temperature
High heat capacity & heat of vaporisation
Transports nutrients & respiratory gases away, out and to cells in blood and urine
Carries the most substances out of any solvent due to its polarity
Ensures adequate blood volume
Participates in chemical reactions
Hydrolysis/condensation
Cushioning around body organs/lubricant around joints/surfaces
Hydrates eyes, mouth, nose
Sean James's family has a history of anemia. He goes online to look at genetics and finds the terms: Chromosomes, Centromere, Telomere and Chromatid. He is confused about their structure and role. He decides to go with his wife Cynthia to meet you and to clear up his confusion. Define the terms above and specify their structure and function.
Chromosomes have two (2) arms
p arm (petite/short arm); q arm (long arm)
Chromosome always orientated with p arm at top
Centromere
Site of spindle fibre attachment (mitosis, meiosis)
Necessary for proper segregation of chromosomes
Telomere
Defined ends of each Chromosome, responsible for stability
Contains repetitive sequence (TTAGGG)
Chromatid
One copy of a duplicated chromosome
Called sister chromatids if joined by the centromere
Sean James goes to the GP after finding out his wife is pregnant. He is confused by a few terms he found when researching about genetics as his family has a history of hemophilia. He asks the doctor about the terms deletion, duplication, translocation and the two types of inversions as he can't seem to understand it. Define the above terms.
Deletion - DNA region is remove
Duplication - DNA region is duplicated/copied and inserted twice
Translocation - Regions of DNA are moved between chromosomes
Pericentric - includes centromere
Paracentric - excludes centromere
What are 4 types of junction complexes. Give a brief definition of each.
Tight junction = Seals off basolateral compartment from apical compartment
Adherent junction = Holds cells together
Desmosome = Strong adhesion between cells
Gap junction = Allows rapid communication between cells
What are the 4 types of passive membrane transport?
Simple Diffusion - directly through phospholipid bilayer
Carrier Mediated Facilitated Diffusion - Via protein carrier specific for one channel, binding of substrate causes shape change in transport protein
Channel Mediated Facilitated Diffusion - through a channel protein, mostly ions selected on basis of size and charge
Osmosis - through phospholipid bilayer and channel protein (aquaporin)
A swab of a patient's saliva with a suspected bacterial infection is sent to the pathology lab. The pathologist sees two different distinct type of cells with different cell wall composition. What are the two types of cell wall and how can they be differentiated?
Gram-positive and Gram negative and
Gram-positive = Thick outer layer of peptidoglycan and complex poly-saccharides called teichoic acids attached to the outside, no lipid membrane
Gram-negative = Thin peptidoglycan layer and have an outer lipid membrane.
Cynthia James finds out she is pregnant and researches online on where she is in her pregnancy. It mentions that 3 layers would have formed. What are these 3 layers and what specific cells do they form?
Endoderm - alveolar cells, thyroid cells and digestive cells
Mesoderm - cardiac muscle cells, muscle cells, tubule cells of the kidney, red blood cells and smooth muscle cells
Ectoderm - Skin cells, neurons, pigment cells
What are the 4 differences between Meiosis and Mitosis?
Mitosis = Growth and Repair, Somatic cells, Genetically identical to parents, 1 division, ends with two diploid cells
Meiosis = Reproduction, Gametes, Genetically different to parents, 2 division, ends with 4 haploid cells
A patient comes into the GP clinic with a persistent cough, fever, a sever headache and a felling of complete exhaustion. The doctor believes the patient has a bacterial infection and chooses to prescribe an antibiotic. What are the 5 actions in which an antibiotic could target a bacteria?
1.Cell Wall Synthesis = destroys peptidoglycan and prevent synthesis
2. Cell Membrane = damage membranes, inhibition of cell wall synthesis
3. Nucleic Acids = targets enzymes that are unique to prokaryotic, specifically replication and transcription enzymes
4. Protein Synthesis = Interfere with ribosome, prokaryotic ribosome different than eukaryotic, targets tRNA
5. Metabolism = folic acid synthesis and para-aminobenzoic acid (PABA)
A woman is 8 months pregnant when she goes to visit the GP for a routine check-up. She mentions to the doctor that she has been drinking a decent amount, about 5 standard drinks every other day. The doctor is worried about the effect of this on the child especially as it crosses the placenta. What determines placental transport and why is the alchol able to cross the placenta?
Size
Hydrophobicity/lipophilicity
Concentration gradient
Consumption & metabolism
Characteristics of microvillus vs basal
- Specific transporters
- Surface area
It is polar and small in size, it can easily diffuse from the maternal blood to the fetal blood through the interstitial space of the placenta.