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).