February/March 2026 Paper 42

The features of an organism are used to classify them into one of five kingdoms. One kingdom is the animal kingdom. State the name of two other kingdoms.

Tick (✓) the statements that describe all organisms in the animal kingdom.

The Felidae are a group of animals commonly known as the cat family. There are 41 species in the cat family. The base sequences in the DNA of these cat species have been compared. Figure 1.1 is a diagram of part of a DNA molecule.

On Figure 1.1, draw an X to identify a base.

DNA is made from four different bases. Base G is one of these bases. State the letters of the three other bases and state which bases pair together.

Figure 1.2 shows the evolutionary relationships between several species of cat based on their DNA sequences. The diagram should be interpreted from left to right. Each branch shows the point at which a new species was formed.

Use Figure 1.2 to determine which species has the closest base sequence to the Felidae ancestor.

Use Figure 1.2 to determine which two species are most closely related. Explain your answer.

Figure 1.3 shows a photomicrograph of part of an animal cell.

State the letters shown in Figure 1.3 that identify the:

State the letter shown in Figure 1.3 that identifies a mitochondrion and describe the functions of mitochondria. letter functions of mitochondria

The cell shown in Figure 1.3 contains ribosomes. State the function of ribosomes.

The magnification of the photomicrograph shown in Figure 1.3 is $\times 18000$. State the other measurement needed to calculate the actual size of the cell.