Cell Structure (SL IB Biology)

A prokaryotic cell has a diameter of 1 µm. The cell is magnified ×50 000 by an electron microscope.

In the electron micrograph that is produced by the electron microscope, what is the diameter of the prokaryotic cell?

The electron micrograph shows the organelles in a leaf cell. A student uses their ruler to measure the length of the scale bar, which they find to be 1.5 cm.

What is the magnification of the micrograph?

The electron micrograph below shows a root vascular system. The magnification of the image is ×200. A student uses a ruler to measure distance X and finds it to be 10 mm.

What is the diameter of the cell labelled Y?

The electron micrograph of the plant cell has a 2 cm scale line labelled 5 µm.

What is the magnification?

Erythrocytes (red blood cells) have a diameter of 7 000 nm. Pancreatic cells have a diameter of 35 µm.

Which of these statements about the relative sizes of these cells is correct?

Which of the following ideas are part of cell theory?

1. Cells are the smallest unit of life
2. Cells show great variety in shape and structure
3. Cells are derived from other cells (pre-existing cells) by division

The role of exocrine gland cells in the pancreas is to secrete digestive enzymes into the pancreatic duct. 

Which of the following organelles does not directly help it to achieve this task? 

Which of the following is not a correct description of a light microscope or an electron microscope?

The list below contains structures that are all features of eukaryotic cells.

1. Nucleus
2. Endoplasmic reticulum
3. Lysosome
4. Chloroplast
5. Mitochondrion

Which of these structures contain(s) a double membrane?

Which set of observations would indicate that a student is observing a eukaryotic cell?

Membrane-bound sacs containing products of metabolism are produced by the endoplasmic reticulum.

Where are these products used?

The image below shows an electron micrograph of a specialised cell.

Which of the following correctly identifies the function of this specialised cell?

Which statements best describe ribosomes?

In prokaryotes, the processes of transcription and translation are said to be coupled, which means they can proceed simultaneously.

Which is the key cellular feature of prokaryotes that allows this to happen?

John Cairns carried out a study in which he kept E. coli bacteria in a solution containing radioactive thymine. 

What was he able to conclude from the results of his study?

Which of the following statements about eukaryotic chromosomes are correct? 

1. Chromosomes are long, linear molecules that can be condensed for compact storage.
2. After DNA replication, the two strands of DNA are held together at the centromere.
3. DNA wraps around histone proteins to form chromatids.

A stage micrometer with small divisions of 0.1 mm was used to calibrate an eyepiece graticule, as shown in the diagram below.

 A slide containing a plant cell was placed on the stage in place of the stage micrometer. 

What is the width of one of the chloroplasts below?

A giant bacterium, Epulopiscium fishelsoni was discovered in 1985.

Which cell structure(s) would enable biologists to classify Epulopiscium as prokaryotic?

A cell which is actively growing is supplied with radioactive amino acids.

Which cell component will show an increase in radioactivity first?

The image below is an electron micrograph of part of an animal cell.

Which of the following options (A to D) would be the site of protein modification and packaging?

The electron micrograph below shows a small section of a palisade mesophyll cell.

Which structure controls the exchange of substances into and out of the cell?