mistake log

why is transpiration important for plants?

supply mineral ions

prevents wilting (keeps plant turgid)

prevents overheating

water for photosynthesis

explain what happens to plant cells in concentrated salt solution to change their appearance

water moves out of cell by osmosis to a lower water potential outside the cell, the cell membrane shrinks from cell wall (plasmolysis)

how many sides does a leaf have?

two - IF ESTIMATING TOTAL SA OF A LEAF MULTIPLY BY TWO A LEAF HAS TWO SIDES

what is the function of the amniotic fluid?

protects from physical damage

why does a pregnant woman need more energy than a non pregnant woman?

more weight as she’s carrying the foetus

growth of foetus

what is micropropagation?

growing small pieces of plant tissue in a lab. Key point - produces genetically identical offspring

how does the stomata affect gas exchange in plants?

oxygen moves out and carbon dioxide moves into the leaf via stomata by diffusion (carbon dioxide used for photosynthesis)

explain the effect of moving air on transpiration rate

-increases it

-water is blown off the leaf, so more water is pulled up from the xylem (transpiration)

-maintains a concentration gradient

increases rate of diffusion

why can lactic acid kill cells?

low pH

denatures enzymes

enucleated

nucleus has been removed

give three advantages of using organs produced by therapeutic cloning compared to using donated organs

won’t be rejected

no shortage of organs

free from infection

describe how ammonium ions can be converted to nitrogen ions in the soil

nitrifying bacteria convert nitrite to nitrate (nitrification)

explain the possible consequences of deforestation on the water cycle

fewer plants → less transpiration, so less water returned to atmosphere, so decreased precipitation

explain how deforestation affects the carbon cycle

fewer plants so less photosynthesis, so less carbon dioxide absorbed from atmosphere

increased CO₂ concentration in atmosphere

less consumption of plants

less decomposition

burning of trees produces CO₂

name two different groups of organisms that act as decomposers

fungi

bacteria

explain how the nitrogen in a nitrate ion in the soil can become the nitrogen in a protein molecule in an animal

absorbed in roots (root hair cell) by active transport

make amino acids in plant

plant eaten by animal

plant digested, amino acid broken down with protease

suggest two advantages of using animal waste as a fertiliser rather than using a chemical fertiliser

less eutrophication

cheaper