OCR Gateway GCSE Biology A cell level systems (B1) overview quiz quiz

Cell wall, chloroplasts and permanent vacuole

Nucleus, mitochondria and ribosomes only

Cell membrane, cytoplasm and many ribosomes throughout

Plasmids, flagella and a single circular loop of DNA

How many times bigger the final image appears than the real object

The ability to distinguish two close points as separate

The brightness of the lamp or light source used to view the slide

The thickness of the specimen mounted on the microscope slide

10 micrometres

100 micrometres

40 micrometres

0.04 micrometres

A with C, and T with G

A with G, and T with C

All four bases pair with each other

A with T, and C with G

Because only a substrate with a complementary shape fits its active site

Because it carries on working well at absolutely every temperature it meets

Because it is completely used up each time the reaction takes place

Because it is able to catalyse any reaction happening anywhere in the cell

It simply keeps working faster and faster, with no upper limit, as the temperature climbs

Its active site changes shape so the substrate no longer fits, and it is denatured

It is killed off, because an enzyme is itself a tiny living organism

It is gradually turned into a substrate that other enzymes act on

$6CO_2 + 6H_2O \rightarrow C_6H_{12}O_6 + 6O_2$

$C_6H_{12}O_6 + 6O_2 \rightarrow 6CO_2 + 6H_2O$

$C_6H_{12}O_6 \rightarrow 2C_2H_5OH + 2CO_2$

$C_6H_{12}O_6 \rightarrow 2C_3H_6O_3$

Carbon dioxide and water

Ethanol and carbon dioxide

Lactic acid

Glucose and oxygen

Exothermic, because it gives out energy to the surroundings

Neutralisation, because it makes water as a product

Anaerobic, because the plant carries it out without oxygen

Endothermic, because it takes in light energy

It falls to one quarter

It falls to exactly one half

It stays exactly the same

It rises to four times as much