Identify the cell, organelle or developmental process first, then use scale, structure, chromosome or expression evidence to justify the biological conclusion.
The photograph shows two human cheek cells on a microscope slide. The mean diameter of human cheek cells is .
Describe a procedure for the accurate determination of the diameter of cell A .
Draw cell A and label the parts of the cell. Include a scale by your drawing.
The photograph below shows part of a transverse section of a plant stem.
Three types of cell are labelled X, Y and Z.
Identify the cell types labelled X, Y and Z. X Y Z
The photograph shows a longitudinal section of where two plant cells meet.
State which of the cells labelled X, Y or Z is shown in this longitudinal section.
Cell
The five stages of cancer are used to describe the size and spread of a cancer in a human body.
The mitotic index of a tissue can be used to determine the stage of cancer.
A higher mitotic index is usually linked to a later stage of cancer.
The mitotic index is calculated using the formula
Tests were performed on three patients, P, Q and R, who had cancer.
The table shows the number of cells that were counted in each stage of the cell cycle per of tissue, taken from the same organ in each patient.
State what is meant by the term tissue.
A student used a microscope to study the tissues in a plant stem and the cell of an animal.
The photograph shows a vascular bundle in a transverse section of the plant stem, as seen using a light microscope.
The photograph shows an animal cell. This photograph was taken using an electron microscope.
Draw this cell as the student would see it under high power of a light microscope.
Label your diagram to show the nucleus, the nucleolus and the nuclear envelope.
State one difference and one similarity between the nuclear envelope and the cell membrane.
Difference
Similarity