Practise Cambridge International AS Biology 1.2 by identifying cell structures, comparing plant, animal and bacterial cells, and applying ATP and virus concepts to exam questions.
Which type of cell will have the highest proportion of its volume taken up with cell structures bound by a single membrane?
ciliated epithelial cell
goblet cell
red blood cell
companion cell
The electron micrograph shows onion root cells prepared using a freeze-fracture technique. The cells were quickly frozen and then physically broken apart. Freeze fracture breaks apart cells along weak areas, such as membranes and the surfaces of organelles.
\(\times 20000\)
Which statement best explains the appearance of the electron micrograph?
The cells were broken apart at the endoplasmic reticulum; structure X is a ribosome.
The cells were broken apart at the nuclear envelope; structure X is a nuclear pore.
The cells were broken apart at the nuclear envelope; structure X is a ribosome.
The cells were broken apart at the tonoplast; structure X is a plasmodesma.
Which row is correct for the structures present in typical plant cells and typical animal cells?
cell structure
plant cell
animal cell
plasmodesmata
present
present
Golgi body
present
not present
centriole
not present
present
tonoplast
not present
not present