Biology weaknesses for June mocks Flashcards
what is an ester bond?
reaction between an acid and an alcohol, water molecule removed
max resolution of TEM
0.0002 Mm
description of image produced by TEM
2Dimage of cell interior
description of image produced by SEM
3D image of surface
max resolution of SEM
0.002 Mm
how to calculate RF value
divide the distance travelled by the component - in other words, the distance from the starting pencil line to the coloured spot -by the distance travelled by the solvent
the two cells produced by mitosis are ….
Genetically Identical
What is a Totipotent stem cell
Can make all cell types
Zygote and early embryo cells are like this
What is a Pluripotent stem cell
Capable of producing all cells derived from a particular germ layer: ectoderm, endoderm, mesoderm.
Present in early embryos
What is a multipotent stem cell
Can make a restricted range of related cell types
E.g: haemopoietic stem cells make red, white blood cells and platelets
What happens in G1 mitosis
Growth (biosynthesis)
Proteins made , organelles replicate
What happens in S in interphase
DNA synthesis
What happens in G2 of interphase
Further growth of cell
Checks DNA for errors
What does the p wave in an electrocardiograph represent
Contraction of the atria
What is the main peak of the heartbeat in an electrocardiograph called
What is it caused by
QRS complex
Contraction of the ventricles
What is the T wave in and electrocardiogram caused by
Relaxation of the ventricles
What does the electrocardiogram represent?
The changes in electrical charge in the heart
Contraction = lose electrical charge (depolarise)
Relaxes = regain charge (repolarise)
How does Tachycardia affect the heart
Fast heart rate at rest, around 120mph
How does Bradycardia affect the heart
Slow heart rate (around 50bpm)
How does poor atrial Contraction effect the heart
How does it show on graph
Shown thru low or unclear P wave, blood isn’t entering ventricles correctly
How Ectopic heartbeat effect heart rate
An ‘extra’ heartbeat interrupting regular rhythm
Can be a ‘one off’
How Atrial flutter affect heart ?
Large regular P waves, atria beating too fast
How Fibrillation affect heart
Very irregular heartbeat. Lose rhythm
How ventricular hypertrophy affect ECG
Cause?
Can be seen as tall R wave on ECG trace.
Caused by thick ventrical wall
Bigeminy heart condition
Each normal heart beat is followed by a premature heartbeat
Components of capillary
-one cell thick Endothelium
Components of veins
- Little smooth muscle or elastic fibre
- Endothelium
- Collagen fibre surrounding outside
- contain valves
- wide lumen
Components of Artery
- Thick muscular walls surrounding elastic tissue
- Endothelium folded allowing it to expand under pressure
- small lumen
- Collagen fibres surrounding outside
Phagocytes _______ pathogens
Engulf
What do you need to say about setting up and using a potometer
-dry leaves, let shoot acclimatise
-cut shoot underwater, at a slant
-all apparatus set up underwater
-reservoir present to prevent air bible entering plant
-take capillary tube out of water and blot to create air bubble
-
Is this in standard form?
3000000
No standard form is 3x10^6
How is a guard cell specialised for its function
Thin outer walls and thicker inner walls.
To allow water in so that it swells to change shape (to close and open stomata)
How is a root hair cell specialised for its function
Many mitochondria, Thin permeable cell wall Extension protruding from cell.
Increase SA, mitochondria for active transport
How is a palisade cell specialised for function
Lots of chloroplast to absorb large amounts of light for photosynthesis
How are elastic fibres used in the airways
Recoil of alveoli and lungs
What is the prokaryotic cell wall made of
Peptodiglycan
What is the fungal cell wall made from
Chitin
What is the plant cell wall made from
Cellulose
How are squamous Epithelial cell specialised for function
squat/flat cells
-once cell thick
To create short diffusion distance
PH is
The change in concentration of hydrogen ions
Are there relatively more or less hydrogen ions in Acid
More hydrogen bonds
Care competitive inhibitors reversible?
Yes
What are opsonins
Molecules, usually antibodies, that bind to antigens and mark for cell phagocytosis
Increase likelihood of phagocytosis
Name 3 bacterial diseases and state if they’re plant or animal
- tb animal
- Bacterial meningitis, A
- ring rot, plant, potato
Name 3 viral diseases and state whether they’re animal or plant
- hiv/aids, animal
- influenza, animal
- TMV, plant
Name 2 potist diseases and state whether they’re plant or animal
- malaria, animal
- Potato blight, P
Name the primary non specific defenses animals have against pathogens
- skin
- lysozyme
- expulsive reflexes
- mucus membranes
- BLOOD CLOTTING + WOUND REPAIR
Percentage change formula
(Finial-initial) /initial
what is the pathogen that causes malaria
Plasmodium
What is meant by autoimmune disease
- abnormal immune response
- against tissues normally in the body
How do T cells speed up clonal selection of B cells
- helper T cells stimulated by antigen-presenting cells
- release cytokines/ interleukins
- these stimulate B cell clonal expansion
4 ways potatoes defend against pathogen
- leaf drop/abscission
- necrosis
- release toxic chemical
- produce callose
Phloem transports
Assimilates
amino acids
Sucrose
How does temperature effect thr erate of transpiration
Increases rate of evaporation
Evidence for translocation
- rate of movement of sugars in phloem is faster than what diffusion could achieve alone
- companion cells decrease the pH of surrounding tissues
How is translocation linked to respiration
Active transport requires energy in the form of ATP
Magnification of TEM
500,000
Mag of SEM
100,000
How does surfactant prevent alveoli from collapsing
Reduce surface tention
Why does hydrostatic pressure decrease as blood moves away from the heart
-fluid moves out of blood
-enters tissue fluid
-down pressure gradient
-proteins too large to leave capillary wall
-HYDROSTATIC PRESSURE GREATER THAN WATER POTENTIAL
-
Why is the left ventricle thickest
- needs more force
- pushes blood against greater resistance
- Pumps blood at higher pressures
- pumps blood to entire body
Two advantages of keeping blood in vessels
Maintain higher blood pressure
Increase rate of flow
Flow can be directed
explain why fetal haemoglobin curve is to left of adult curve
- placenta has low PO2
- Adult haem will dissociate at lower PO2
- fetal haemoglobin has higher affinity for o2
- fetal haemoglobin is able to take up 02 in placenta at low pO2
when does oxygen associate to haemoglobin
at high pO2
max resolution of light microscopes
0.2 Mm
what process do channel proteins do
facilitated diffusion
what process do carrier proteins do
active transport
3 roles of plasma membranes
- partially permeable barrier, control what enters + leaves
- site of chemical reactions
- receptors for hormones + drugs to bind
What is pinocytosis
Liquid absorbed by cell
What is phagocytosis
Liquid absorbed
