cell structure Questions with Correct Answers

does a white blood cell have a cell wall does a white blood cell have a cell membrane does a white blood cell have a nucleus does a bacterial cell have a cell wall does a bacterial cell have a cell membrane does a bacterial cell have a nucleus - ANSWERSno yes yes yes yes no (c) Some scientists support the theory that mitochondria are organelles that evolved from prokaryotic cells. (i) Give one piece of evidence that supports the theory that mitochondria evolved from prokaryotic cells. - ANSWERSCircular DNA / smaller/70S ribosomes / no introns / no histones/proteins associated with DNA; What is the advantage to cells of having mitochondria? - ANSWERSAble to respire aerobically; So make (more) ATP/ release (more) energy; (b) (i) The organelles labelled X all have very similar shapes in this cell. Explain why they appear to have different shapes in this drawing. - ANSWERS(Sections cut at) different angles/in different planes; Large numbers of organelles X and Z are found in mucus-secreting cells. Explain why. - ANSWERSZ modifies/packages/transports/secretes mucus/ Z adds sugars to proteins; X provides ATP/energy (for this); Explain how these structures help in the absorption of substances from the small intestine. - ANSWERSmicrovilli; they are there to increase the surface area (ii) Explain why an electron microscope shows more detail of cell structure than a light microscope. - ANSWERSelectron microscope has a greater resolving power / objects closer together can be distinguished; electron (beams) have a shorter wavelength; Small samples of plant tissue were placed in a cold, isotonic solution and then treated to break open the cells to release the organelles. The different organelles were then separated. Describe a technique that could be used to (i) break open the cells; separate the organelles. - ANSWERShomogeniser / blender / pestle and mortar / description e.g. grind with sand; centrifuge ne group of organelles was placed in a hypotonic solution. The diagram shows one of these organelles seen under an electron microscope before and after it was placed in the hypotonic solution. (b) Name the organelle. - ANSWERSchloroplasts Give two features shown in the drawing which are evidence that this cell is eukaryotic. - ANSWERSnamed organelle e.g. nucleus / nuclear envelope; vacuole; chloroplast; RER; mitochondrion; no membrane bound organelles; (only award if no organelles named) (reject ribosomes, cell membrane, cell wall) ref to large(r) size Give one way in which a typical animal cell differs from the cell shown in the drawing. - ANSWERSno cell wall (permanent) / (large) vacuole / chloroplasts / smaller; Give two ways in which the structure of this bacterium is similar to the structure of a cell lining the human small intestine. - ANSWERScytoplasm; ribosomes; Give two ways in which the structure of this bacterium differs from the structure of a cell lining the human small intestine. - ANSWERScell wall; capsule; flagellum; mesosome; (d) The epithelial cells of the small intestine have large numbers of organelle A. Explain how this is an adaptation for the function of these cells. - ANSWERSprovide / produce energy or ATP (reject create energy); (disqualify first mark if ' for respiration') high respiration (rate) (accept lots) for active uptake / transport (accept description); absorption of digested food / substances / products / correctly named product