diffusion and osmosis Flashcards
name the substance that causes change in mass of the plant tissue
water
explain the term diffusion
spreading out of molecules from a region of higher concentration to a region of lower concentration
explain the term osmosis
movement of water molecules across a semi permeable from a region of higher water concentration to a region of lower concentration
describe in detail what happens to a plant cell that is placed in a solution with less dissolved solutes than its cytoplasm
water enters the cell, the cell becomes turgid
describe what would happen to an animal cell if it was exposed to a place in a solution with less dissolved solutes than its cytoplasm
burst
describe the biological basis and the advantage of having high salt or water concentration on food
water leaves the cell of micro-organisms present and they die which results in an extended shelf life
living cells can be classified into two major types based on the presence or absence of cell organelles. what are the names of these two major types of cells
-eukaryotic
-prokaryotic
how do turgid cells remain its shape
cell wall
outline how a scientist uses a coverslip
lowered at an angle
explain why a coverslip is used
to prevent cell from drying out
when prepping a sample of a cheek cells on a microscope slide, why did you apply methylene blue to the cells
to stain the cells to see clearer
when extracting DNA from plant tissue, why did you use washing up liquid
breakdown membrane
when extracting DNA from plant tissue, why did you use freezer cold ethanol
to make DNA insoluble
when using seeds to investigate the effect of IAA on plant tissue, why did you carry out a serial dilution of an IAA solution
to make solutions of different concentrations
when using seeds to investigate the effect of IAA on plant tissue, why did you place the seeds on a grid in petri dishes
to measure the growth
when carrying out an activity to investigate osmosis why did you use visking tubing
act as a selectively permeable membrane
when carrying out an activity to investigate osmosis how did you know osmosis had taken place
tubing got fuller
give a detailed explanation for - high sugar or high salt concentration are used in preservation of food
food decay by bacteria
what is the purpose of replicates in scientific experimentation
to verify result
what is meant by the term hypothesis
an untested explanation
when investigating the conditions necessary for seed germination, describe how you provided an oxygen free environment
boiled water which has been cooled
when investigating the conditions necessary for seed germination, describe how you determined that germination had taken place
radicles observed
how did you prepare the section of a dicotyledonous stem
cut a thin section
when isolating DNA from plant tissue give a reason for adding salt to the chopped plant tissue
to clump DNA
when isolating DNA from plant tissue why was the mixture contains the chopped plant tissue, salt and washing liquid kept at 60*C for a period of time
to denature DNA
what do you understand by the term turgor in plant cells
pressure or cell contents against the cell wall
how do plant cells remain turgid for a considerable period of time
by taking in as much water as they lose
what happens to a plant if many of its cells turgidity
wilt
explain the term selectively permeable
a selectively permeable membrane allows some but not all molecules to pass through
suggest an advantage to the cell of having a selectively permeable membrane
substance can be kept in
name two substances that enter a human muscle cell by osmosis
-oxygen
-water
suggest a way in which turgor is of value to plants
support
when demonstrating osmosis, for what purpose did you use Viking tubing, potato tissue or some similar material
light - vary lmap distance
in the microscopic examination of a plant cell, name the stain that you used and the colour it imparted to the cell wall
iodine- yellow
how did you apply the stain to the cells on the slide
dropper
when investigating digestive activity during seed germination, how did you supply a substrate suitable for the digestive enzymes
milk agar
when investigating digestive activity during seed germination, how did you ensure that no digestive enzymes were available on the control plate
boiled seeds
explain the term homeostasis
maintenance of a constant internal environment
explain the term active transport
movement of molecules using energy
state one way in which the liver contributes to homeostasis
absorption of water
state one way in which the lungs contributes to homeostasis
excretion of water
state one way in which the nephrons of kidneys contributes to homeostasis
excretion of water
describe the role of the skin in controlling body temperature
too hot - sweat
too cold - hair stands up
state the precise location of the cell membrane in plant cells
inside the cell wall
with what type of cell do you associate membrane bond organelles
eukaryotic
what corresponding term is used to describe bacterial cells
prokaryotic
why is diffusion known as passive transport
no energy
osmosis may be described as a special case of diffusions, explain why
movement of water
name the structure by which amoeba gets rid of excess water that has entered by osmosis
contractile vacuole
give two locations in a cell at which there is a selectively permeable membrane
choloroplast, nucleus
explain the biological basis for the used of high sugar or high salt concentration in the preservation of food
bacteria lose water by osmosis
