Biology Flashcards Practice Questions

which of the labelled regions would be directly invovled in learning to play a musical instrument

w and z

the drug metoprolol prevents stimulation of post synaptic receptors in the sympathetic nervous system

which of the following conditions could this drug be used to treat

1) muscle fatigue

2)tachycardia

3)high blood pressure

tachcardia and high blood pressure

explain why glucose is required for the contraction of skeletal muscle

• glucose is used in respiration to produce ATP

• ATP is needed for breaking cross bridges between myosin and actin

• ATP for active transport of calcium ions

outline the importance of photosynthetic pigments in photosynthesis

pigments absorb sunlight

accesory pigments pass energy to primary pigments

primary pigments become oxidised

for light depedent reactions

why may some protists that absorb chlorophyll c need pigments that are different to other photosynthetic organisms

because they absorb light of shorter wavelengths

outline the differences between the chloroplasts in the image and the chloroplasts in flowering plants

the image has fewer thylakoids than flowering plants

the image doesnt have nay starch grains but the flowering plants would

explain how hydrophobic tails contribute to the stability of the plasma membrane

they form a bilayer seperating the 2 aqueous regions

outline the roles of intracellular membranes

• provides attachment sites for enzymes

• provides comparmentalisation of organelles

• allows formation of concentration gradients

give three properties of cellulose which mske it suitable as the basis of cell walls

cellulose is not water soluable

it is fibourous to withstand high pressure

it is flexible

it is inert

outline the processes involved into the generation of ATP through chemiososis

• occurs in mitochondria inloving the inner membrane

• hydrogen ions are pumped out of the matrix into intermembrane space

• creating a proton gradient acitvating the proton movement force

• atp synthase produces ATP through ADP and PI

• H+ ions move form an area of high concentration to low concentration

state two variables which need to be controllled in an investigation with betroot and pigment loss

the type of beetroot the time taken to wash the sample

The following information has been discovered about the effects of TTX on nerve cells: • TTX binds to the external surface of the voltage-gated sodium ion channels in the axon membrane. • Binding of TTX changes the tertiary structure of the channel. • This means the channel cannot open

Using the information provided, explain how TTX affects the activity of neurones.

sodium ions cannot enter the channel

meaning the membrane cannot be depolarised

meaning there is no action potential generated

meaning there is no release of neurotransmitters

explain the effects of the slowing of conduction in the perkyne fibres

slows heart rate

impulses are transmitted

increases diastiole time

why is transmission of aciton potentials along the axon slower in the absence of saltatory conduction

because the whole axon needs to be depolarised

during