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