Cell Structure
614 questions· page 1 of 62
In an electron micrograph, the length of a mitochondrion is measured as . The magnification of the electron micrograph is .
What is the actual length of the mitochondrion?
Options
A
B
C
D
There is a theory that mitochondria and chloroplasts were originally free-living prokaryotes. It is thought that millions of years ago these free-living prokaryotes were taken into larger cells by endocytosis where, instead of being digested, they became functional organelles.
Which features of mitochondria and chloroplasts support this theory?
1 Mitochondria and chloroplasts are surrounded by double membranes.
2 Mitochondria and chloroplasts have small, circular DNA.
3 Mitochondria and chloroplasts synthesise proteins.
Options
A 1, 2 and 3
B 1 and 2 only
C 1 and 3 only
D 2 and 3 only
Which row correctly describes a function of each cell structure?
Options
| lysosome | mitochondrion | smooth endoplasmic reticulum | |
|---|---|---|---|
| A | digestion of unwanted structures | abundant in sites of active transport | processing of proteins |
| B | digestion of unwanted structures | ATP synthesis | lipid production |
| C | spherical sacs containing hydrolytic enzymes | abundant in sites of active transport | lipid production |
| D | spherical sacs containing hydrolytic enzymes | ATP synthesis | processing of proteins |
Which cell components are present in typical prokaryotic cells?
Options
| cell wall | 80S ribosomes | |
|---|---|---|
| A | ✓ | ✓ |
| B | ✓ | ✗ |
| C | ✗ | ✗ |
| D | ✗ | ✓ |
key
✓ = present
✗ = not present
X-ray analysis of fossilised cells found in rocks in central India dating back 1.6 billion years has revealed several features.
1 The cells are up to long.
2 The cells are joined end to end to form filaments.
3 The cells contain some internal cell structures.
4 The cells are surrounded by a cell wall.
Which two features, when taken together, provide most support for the conclusion that the cells are plant cells?
Options
A 1 and 3
B 1 and 4
C 2 and 3
D 2 and 4
The electron micrograph shows an organelle found in some cells of many multicellular organisms.
Which row shows structures that are expected to be present in cells that contain this organelle?
Options
| cell wall | centrioles | plasmodesmata | |
|---|---|---|---|
| A | ✗ | ✓ | ✗ |
| B | ✓ | ✗ | ✗ |
| C | ✗ | ✓ | ✓ |
| D | ✓ | ✗ | ✓ |
key
✓ = expected to be present
✗ = not expected to be present
Which molecule forms a bilayer in the cell surface membrane of a bacterial cell?
Options
A fatty acid
B peptidoglycan
C phospholipid
D cholesterol
Which row correctly matches each description to cilia or root hairs?
Options
| contain vacuoles | more than one present per cell | |
|---|---|---|
| A | root hairs | root hairs |
| B | cilia | cilia |
| C | root hairs | cilia |
| D | cilia | root hairs |
Which statements about light microscopes are correct?
1 To calculate the magnification of a light microscope, the eyepiece lens and objective lens magnifications are added together.
2 The resolution of a light microscope is limited by the wavelength of light.
3 The divisions on the scale on a stage micrometer are closer together than the divisions on the scale on an eyepiece graticule.
Options
A 1, 2 and 3
B 1 and 2 only
C 2 only
D 3 only
A student measured the width of a mitochondrion in an electron micrograph of an animal cell with a magnification of . The width was .
What was the actual width of the mitochondrion?
Options
A
B
C
D