Characteristics, Classification & Features of Organisms (Cambridge (CIE) IGCSE Biology)

Table 1 shows the names of three groups of arthropods and some of their characteristics.

Place ticks (✓) in the boxes to show the characteristics present in each group. 

Table 1

All living organisms show the same seven characteristics.

State four of the characteristics of living organisms.

Fig. 1 shows the apparatus used by some students during an investigation.

The apparatus is drawn as seen from above.

Fig. 1

Some arthropods were placed in the container.

A drop of red dye was inserted into the capillary tube.

The drop of red dye in the capillary tube gradually moved towards the arthropods.

(i)

Explain why the drop of red dye moved towards the arthropods.

The investigation shown in Fig. 1 was repeated at different temperatures.

Fig. 2 shows the results. 

[3]

Fig. 2

(ii)

State the trend shown in Fig. 2.

[1]

(iii)

Calculate the percentage increase in the rate of dye movement between 10°C and 20°C. 

Show your working.

[2]

(i)

State the group of arthropods the student used in Fig. 1.

[1]

(ii)

Describe the features visible in Fig. 1 that identify this group.

[3]

The animal in Fig. 1 is a chimpanzee.

Fig. 1

(i)

The chimpanzee is a vertebrate. 

State the main group of vertebrates to which the chimpanzee belongs. 

[1]

(ii)

State two features, visible in Fig. 1, which suggest that it belongs to this group of vertebrates.

[2]

The chimpanzee lives in forests in central and western Africa. The chimpanzee is classified as an endangered species because its population has decreased greatly.

(i)

Suggest why the chimpanzee population has decreased.

[2]

(ii)

Describe how a captive breeding programme can help to conserve chimpanzees in the wild.

[2]

(iii)

State two methods, other than captive breeding, of conserving endangered species.

[2]

The binomial system of naming species gives chimpanzees the name Pan troglodytes.

Describe what is meant by the binomial system of naming species.

Chimpanzees are classified taxonomically as a single species, Pan troglodytes.

Define what is meant by the term species. 

A scientist discovered a new organism and observed some cells from the organism. Table 1 below shows some of the features observed during examination. 

Table 1

Suggest which Kingdom the organism belongs to using the observations recorded by the scientist. 

Extended only

The scientist used DNA sequencing to further study the cells. 

Explain why the scientist used DNA sequencing. 

Extended only

Table 2 shows the DNA base sequence of four species of cat.

Table 2

Explain which two species are most closely related.  

Extended

Cats are animals that share some similarities and differences with prokaryotes.

Compare the main features of animals and prokaryotes.

Extended only

Flowering plants can be divided into two groups.

(i)

State the two groups of flowering plants.

[1]

(ii)

Explain how to distinguish between the two groups.

[3]

 Extended only

A student found the plant shown in Fig. 1 growing in the school grounds.

Fig. 1

Explain what type of plant this would be classified as. 

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The student investigated how the number of leaves on the plant varied. The student visited three different sites within the school grounds and counted the leaves found on one plant within each site. 

Table 1 shows the results of his experiment. 

Table 1

Use the grid below to draw a graph of these results.

[4]

Extended only

Determine how the student could improve the reliability of their data.

The organisms shown in Fig. 1 are a group of invertebrates called arachnids. 

Fig. 1

Describe the common features of arachnids visible in Fig. 1.

[1]

Use the key shown below to identify the arachnids shown in Fig. 1

. 

Extended only

Dichotomous keys can be used to help classify organisms. 

Explain the purpose of classification systems. 

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When attempting to classify organisms based on their characteristics, several types of differences between organisms can be observed. These are shown in Table 1.

Table 1

Reorder differences A - E into the order of the amount of detail that can be gained, starting with the least detailed.  

Extended only

When carrying out DNA base sequence comparisons between species, explain why the same gene has to be selected from each species for sequencing. 

Extended only

Table 2 gives information about the amino acids that go into the chain of haemoglobin protein found in the blood of various animal species. The second column shows how many amino acids are different in the haemoglobin of that species to that of humans. 

Table 2

Humans and gibbons evolved separately from a common ancestor about 18 million years ago.

Calculate an estimate of how many years ago the evolution of frogs diverged from that of humans. 

Give your answer in standard form. 

Classification systems largely depend on grouping species by the features that they share. All organisms can be classified using a hierarchical system starting with Kingdom and ending with the Genus and Species. 

Suggest the benefits of classifying organisms in a hierarchical system.

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Explain why, in evolutionary terms, the more recent a common ancestor between two species, the more closely related those two species are. 

Extended only

Fig. 1 shows the evolution of a group of primates and their associated DNA sequences.

Fig. 1

Using the information provided in Fig. 1 and your knowledge of DNA sequencing as a means for classification, determine with an explanation, which two primates are most closely related. 

Extended only

Explain what Fig. 1 can tell you about the relationship between ancestors of primates.

Extended only

Fig. 1 shows a unicellular organism found in freshwater.

Fig.1

Name the Kingdom this organisms belongs to.

[1]

Extended only

Explain the features of the organism in Fig. 1 that distinguish it from other organisms.

The organism shown in Fig. 1 is found in freshwater and must control its internal conditions by balancing the amount of water that moves in and out of the cell across the cell membrane. 

(i)

State the process by which water moves in and out of the cell. 

[1]

(ii)

As the organism digests its prey, the nutrients released can lower the water potential of the cell.

Suggest how this might affect the movement of water into or out of the cell. 

[2]

(iii)

The cell shown contains a structure called a contractile vacuole, which expels excess water from the cell. As well as excess water, they also remove waste materials from the cell. 

State the characteristic of living organism that the contractile vacuole carries out.

[1]

Fig. 2 shows the same organism from part (a) and it's hunting technique. 

Fig. 2

Explain the characteristics of living organisms that would be expressed in this process. 

A student investigated the relationship between the wavelength of a light source and seedling height. The student used strawberry seedlings and grew the plants in an enclosed box with the coloured light as the only available source of light for the plant. The student watered each seedling daily with 30ml of water. He grew the seedlings for 3 weeks before taking the final measurement. 

Suggest the characteristics of living organisms reflected in this investigation. 

The student grew the strawberry seedlings under different coloured lights. Their results are shown in Table 1. 

Table 1

(i)

Explain why the student calculated the growth of seedlings rather than using the final height.

[2]

(ii)

Calculate the percentage change in the growth of the control group of seedlings. Round your answer to the nearest whole number.

[2]

(iii)

Explain the need for a control group of seedlings.

[1]

A gardener also investigated the effect of changing wavelengths of light on the height of different types of vegetable seedlings. The gardener used an enclosed box and lamps with different colours of light as the only available light source. The gardener watered the plants daily from a watering can. The gardener grew five seedlings of each vegetable over a period of four weeks, measuring their height daily. At the end of the investigation, these measurements were used to calculate their average height. 

Their results are shown in Fig. 1. 

Fig. 1

Suggest with a reason, which light source the gardener should use to produce the tallest vegetable plants. 

Compare the gardener's experimental method with that of the student's.

Dichotomous keys can be used to identify organisms based on a series of questions about their features.

Fig. 1 shows a group of leaves. 

Fig. 1

Suggest a dichotomous key for the leaves shown in Fig. 1 by completing Table 1. An example has been done for you. 

Table 1

Fig. 2 shows a different type of dichotomous key where invertebrates are classified. 

Fig. 2

Complete the dichotomous key to show the classification of arthropods into their four sub groups. 

Extended only

Fig. 3 shows a range of different plants

Fig. 3

(i)

State whether plants A-C are monocotyledons or dicotyledons.

[3]

(ii)

Identify the type of plant shown in image D and explain your answer.

[2]