QUESTIONS THAT COULD BE ON TOPIC TEST Flashcards
describe the limitations of using a dialysing tube as the plasma membrane
dialysising tube cannot model the proteins eg. carrier or channel proteins embedded in the celluar memrbane which assist transport of materials across the membrane
differ in feautes of dinoflagellate and bacterium
a dino flagellate would contain membrna bound orangelles, whereas bacteria would not
describe how an amoeba, heterophic protist, may engulf bacteria
the amoebas or heterophicn protistsplasma membrane would surround the bacterium, fusing to form a vesicle containing the bacteria which would then enter the amoeba to be digested
compare the chances of survival of two dino flagellates in a low light enviorment, assuming one has chlorpplasts with granum containing fewer thykalids and the other has chlroplast with granum containing many thykloids.Justify your answer
the dinoflagellate with many thykaloids is more likely to survive in low light because more thykaloids should allow more light to be absorbed for photosythensis.
In a low light enviornemnet fewer thyalkoids may mean not enough light is absorbed for suffifencet level of photythensis for survival.
on the surface of the plasma membrane are some carbohydrate protrusions. name the complex consisitng of these protusions and a phosophlipid and descibre the function of these protusions
glycoplipids
glycolipids act as receptors and assist in cell signallin
there is a hgihg concentraiton of a certia ion outside the cell than inside the cell. Justify the pathwya that the ion takes
The ion would move through the protien channel via faciliated diffusion as it is a charged molceule repelled by the fatty acid phosophlipid tails.
It would move down the concentration gradient from an area of low solute concentraiton to an area of high solute concentration to the intracelluar region
suggest why bacteria have developed antibiotic resistance over short period of time since the antibiotics were devleoped and widely used, compared to mutlicelluar ogranisms which evolve much more slowly
binary fission is a very quick process compares to reproduction in mutlicelluar organisms
therfeore, bacteria undergos DNA mutations and evolutions by selection by the antibiotics much quicker than mutlicelluar organisms do
disadvatnage of binary fission
lack of diveristy
What is cancer and what causes it
cancer is a disease taht spreads uncontrollably due to malfunctions of regulatory processes of cell devision.
It often results from exposure to environmental factors like carcinogens or genetic factorsthat make an individaul more susceptible to developing cance.r
besides the loss of stem cells, what is a possible side effect of chemotherapy. Explain why this side affect may arise
Infertility may occur due to chemotehrapy doing damage to normal cells in addition to cancer cells
Are stem cells pluripotent or somatic. Justify your answer
stem cells are somatic because pluripotent stem cells are only found in embyros whilst somatic stem cells can be found in adults
What is a possible side effect of stem cell transplant?
the body of the stem cell recipient may reject the donor stem cell
describe two ways in which cancer cells flourish over normal human cells
cancer cells induce the formation of blood supply (angiogenesis) and thus receive extra nutrients and blood than normal cells
In some plants, a modified leaf forms an insect trap. ‘Motor cells’ are located along the midrib of the modified leaf. In their resting state, these cells are turgid and contain potassium ions at a concentration higher than the surrounding fluid. When the trap is triggered, potassium ions stream out of the motor cells through ion channels. The cells lose their turgidity. The pressure in the surrounding cells then causes the modified leaf to bend and so the trap closes.
When the trap is opening, by what process are potassium ions moved into the motor cells?
Explain your answer.
Active transport, because ATP energy is required to move the potassium ions into the motor cell against their concentration gradient.
n some plants, a modified leaf forms an insect trap. ‘Motor cells’ are located along the midrib of the modified leaf. In their resting state, these cells are turgid and contain potassium ions at a concentration higher than the surrounding fluid. When the trap is triggered, potassium ions stream out of the motor cells through ion channels. The cells lose their turgidity. The pressure in the surrounding cells then causes the modified leaf to bend and so the trap closes.
When the trap is closing, by what process do potassium ions stream out of the cell?
Explain your answer.
Facilitated diffusion, because the ions are moving down a concentration gradient, and through a channel protein (ion channel).
In some plants, a modified leaf forms an insect trap. ‘Motor cells’ are located along the midrib of the modified leaf. In their resting state, these cells are turgid and contain potassium ions at a concentration higher than the surrounding fluid. When the trap is triggered, potassium ions stream out of the motor cells through ion channels. The cells lose their turgidity. The pressure in the surrounding cells then causes the modified leaf to bend and so the trap closes.
Explain why the cells lose their turgidity when potassium ions stream out of the motor cells.
As the potassium ions move out of the motor cells, water also moves out by osmosis. As a result, ion concentration outside the cell increases. Therefore, the cell loses its turgidity
Chlamydomonas are classified into Kingdom Protista, Phylum Chlorophyta. Each cell has a cell wall made of a complex molecule called glycoprotein.
In what way is this cell wall not typical of a true plant cell?
Plant cell walls are made of cellulose, not glycoprotein.
incorrect statements about the cell theory
all cells require glucose to meet their deamdns
ALL cells can produce new cells from preexisiting cells
do all plantcells contian chrlopalst
no root cells have no chlropalasr
fungi cell walls r made of
chitin
Eukaryotes have membran bound organelles that result in the formation of comparmtent like structuers; this is usefule because
it enables partiuclar molcuelcs to selcvltey enter aneexit the cell
which structure would play the most direct role in excretion of sweat during excerise
RER
sOME CELLS in the body such as entercytoes(ntestintal absorptive cells are involved in the uptake of moleucles in the body. Amino acids are one such molecule absorbed from digested food in the small intestine into the entercytoes lining gut wall.
By what process would the amino acids be taken in entercyotes if a low portein content meal was eaten
ACTIVE TRANSPORT
It is notde that bacteria cells are much smaller in size than similary shaped typicak eukaryotic cell. Explain why this made an advnatage to bactiera
bacteria has agreater surface area to volume ratio, which signinfcal increase the effiency of transport of materials across the cell’s plasma membrane.
Prokaryoteiccells such as bactiera do not have mmebrane bound organelles embbeded in their cytoplasm. This is a fundmanetalchrastctierisic of eukayrotic cells. Explain the purpsoe fo this feature
the presence of mmebrane bound organlles allows for the compartemalismsaton of cytosol in eukaryotic cells, creating a varieyt of intracelluar environemnet facilating speicifc biochemical functions of differnet organelles.
Describe the chemical reactio that takes place to join aino acids together for ribosomes
The chemical reacitonthat produces proteins is condensaiton polymerisation reaction. Eneegry is an input and water is an output of this endergonic reaction as each amino acid comoner adds to the chain.
chemical equation of hpotheystehnsis
6CO2+6H20 chlorplhyll/sunlight> C6 H12 06+60^2
photyothenseitc bacteria such as cynobacteria have been proposed for use byy othre scietnists. Wy might these be more benfifiac in plant speicifes
bactria may be more energy dense than plants, and easier to culture hence requiring frewer resources to grow the samea mount of nutrients as bacteri
3 ways to increase surface area
decreasing size
flattening shape
folding
Compare the DNA found in a cell during G1 phase and G2 phase.
DNA is in its first phase of interphase in G1 phase whereas in the G2 phase DNA is in its final stage of interphase. In the G1 phase DNA has not been replicated yet so it would contain 46 chromeosm adn 46 chroamtids. Whereas, in the G2 phase the DNA has already gone through the S phase and been duplicated, therefore the cell contains 46 chroomes and 92 chromatids.
an example of pluripotent cells and where they come from
embyronic stem cells come from a blastocyte
an example of multipotent cells and where they comefrom
an exmaple are blood cells which come from the bone marrow
An exmaple of totipotent cells andwhere they come from
a zygote which comes frm sperm and egg
An example of a unipotent cell and where it comes from
unipotent cell example is lung cell which comes from a mutlipotent cell
Why would the arrow go in the direction drawn(area of high ion cncentration outsdie the cell to low ion coencntraitoninsidethecell)
The ions would move thorugh the channel proteins via facilated diffusion as it is a charge molecule replled by the hydrophobic tails. It would move down the concentration gradeitn to the intraceluar region
