B1a - cell structure and microscopy exam questions Flashcards
name two pieces of laboratory equipment the student could have used to prepare cells to view using a microscope (2 marks)
- (microscope) slide
- cover slip
- dye/stain
- needle
- scalpel
- pipette/dropper
- tweezers/forceps
- allow swab (to collect cells)
why might the student not be able to see anything when looking through the eyepiece lens (1 mark)
- no cells in the field of view
- slide not in the correct position
- mirror not in correct position
- allow light / microscope not switched on
/ plugged in - (objective) lens not clicked into place or (objective) lens dirty
- (student is) looking at a (large) air bubble
- (the microscope is) not focused
- allow student did not stain the cells
- allow idea of magnification not being
high enough
compare the structure of a red blood cell with the structure of a plant cell (6 marks)
differences
- red blood cell has no nucleus OR plant cell has nucleus
- red blood cell has no cell wall OR plant cell has a cell wall
- red blood cell is a biconcave disc OR there are many different shapes of plant cell
- red blood cell contains haemoglobin OR plant cells do not contain haemoglobin
- red blood cells do not contain chlorophyll OR plant cells (may) contain chlorophyll
- red blood cell has no chloroplasts OR plant cell has chloroplasts
- red blood cell has no (permanent) vacuole OR plant cell has (permanent) vacuole
- red blood cells are (much) smaller than plant cells
similarities
- both have: cytoplasm, cell membrane, pigments (although they are different)
- ignore references to mitochondria and ribosomes
explain why a red blood cell bursts and a plant cell does not burst when placed into a beaker of water (2 marks)
- water enters cells by osmosis
- ignore information on osmosis
- allow water enters cell and cell starts to swell
- AND plant cell has a cell wall (which stops it from bursting)
- allow red blood cell has no cell wall (so it swells and bursts)
complete the sentences: (3 marks)
- Plant cells absorb substances from the soil.
- Plant cells use osmosis to absorb ____________.
- Plant cells use active transport to absorb ____________________.
- Active transport moves substances against the concentration gradient and needs __________________.
IN THIS ORDER ONLY
1. water
2. mineral ions
3. energy
how is a root hair cell adapted to increase absorption of substances from the soil (1 mark)
large surface area
how do the following features help the sperm cell carry out its function (2 marks)
- contains a nucleus
- has a long tail
- to provide the chromosomes for fertilisation
- to help the cell swim to the egg
describe one feature of a nerve cell which helps it to carry out its function (1 mark)
- long
- has branches
- has insulation
what is the function of the cell wall (1 mark)
to strengthen the cell
which part of the cell makes it green in colour (1 mark)
chloroplast
what is the function of these sub-cellular structures: (3 marks)
- cell membrane
- mitochondria
- ribosomes
IN THIS ORDER ONLY
1. controls transport of substances into the cell
2. where energy is released
3. where proteins are made
how can you get a clear image when looking at a cell through a microscope (1 mark)
adjust the focus knob
give two similarities between a prokaryotic cell and a eukaryotic cell (2 marks)
- both have cytoplasm
- both have cell membrane
- both have ribosomes
- both have DNA/genetic material
give three differences between a prokaryotic cell ad a eukaryotic cell (3 marks)
- prokaryotic cell is smaller OR eukaryotic cell is larger
- prokaryotic cell does not have mitochondria OR eukaryotic cell does
- prokaryotic cell has no nucleus OR eukaryotic cell does
- prokaryotic cell has a single loop of DNA
- prokaryotic cell has plasmids
name the type of cell division that produces genetically identical body cells for growth and repair (1 mark)
mitosis (correct spelling only)
