Classification

Plesiosaurs are extinct reptiles that lived in the ocean.

Figure 5 shows a fossil of a plesiosaur.

Plesiosaurs may have moved rapidly upwards to hold their heads above the water surface to search for prey.

What type of adaptation was the rapid upwards movement?

Give two biotic factors that may have caused the extinction of plesiosaurs.

Describe how the plesiosaur fossil in Figure 5 could have been formed.

Scientists use fossils to study evolution.

Suggest two reasons why scientists cannot study the mutations involved in the evolution of plesiosaurs.

Do not refer to extinction in your answer.

Table 1 shows part of the classification of a plesiosaur.

Complete Table 1.

Give the binomial name of the plesiosaur in Table 1.

Figure 8 shows an evolutionary tree.

Which species in Figure 8 is most closely related to lions?

Tick (✓) one box.

Tigers are more closely related to snow leopards than to jaguars.

Draw a line on Figure 8 to show the evolution of tigers.

Label the line ‘Tiger’.

What is represented by species R on Figure 8 ?

Tick (✓) one box.

Complete the sentence.

Choose the answer from the box.

Evolution occurs by the process of.

Species can become extinct.

Give two possible causes of extinction.

Fossils are used to study the evolution of some species.

Suggest one reason why fossils are used to study evolution.

Some bacteria have evolved to be resistant to penicillin.

Penicillin is an antibiotic.

How has the process of evolution produced bacteria that are resistant to penicillin?

Write the stages, A, B, C, D and E in the correct order.

The first stage has been completed for you.

A The bacteria with mutations are more likely to survive.

B The population of bacteria is exposed to penicillin.

C The mutation for resistance to penicillin is passed on to offspring.

D Variation in the population of bacteria is caused by mutation.

E The surviving bacteria reproduce.

New antibiotics are not likely to control the spread of bacteria that are resistant to antibiotics.

What are two reasons why?

Tick (✓) two boxes.

Potatoes are a food crop.

Potato plants are classified as eukaryota.

What type of classification group is eukaryota?

Tick (✓) one box.

Potato plants can reproduce by asexual reproduction.

Which statement is true for asexual reproduction?

Tick (✓) one box.

Flowers of potato plants contain gametes for sexual reproduction.

How is a gamete different from other cells in a potato plant?

Tick (✓) one box.

Plants in the same genus as potatoes have been studied by scientists.

Describe one way a new plant species could be identified as being in the same genus as potatoes.

Scientists have collected and stored seeds from species in the same genus as potatoes.

In the future, these seeds may be used for genetic modification of potato plants.

Genetically modified potato plants could help supply food to the human population as the climate changes.

Explain why genetic modification of crop plants may be important for the human population to survive climate change.

Potatoes are a food crop.

Potato plants are classified as eukaryota.

What type of classification group is eukaryota?

Tick () one box.

Potato plants can reproduce by asexual reproduction.

Which statement is true for asexual reproduction?

Tick () one box.

Flowers of potato plants contain gametes for sexual reproduction.

How is a gamete different from other cells in a potato plant?

Tick () one box.

Plants in the same genus as potatoes have been studied by scientists.

Describe one way a new plant species could be identified as being in the same genus as potatoes.

Scientists have collected and stored seeds from species in the same genus as potatoes.

In the future, these seeds may be used for genetic modification of potato plants.

Genetically modified potato plants could help supply food to the human population as the climate changes.

Explain why genetic modification of crop plants may be important for the human population to survive climate change.

Salmon are fish. A species of salmon has the binomial name Oncorhynchus keta.

Table 3 shows the classification for this species of salmon. Complete Table 3. Choose answers from the box.

Figure 5 shows sea lice attached to the skin of a salmon.

Sea lice are small animals that feed on the skin and blood of salmon. On a salmon farm, the salmon are fed with food made from soya plants.

Which food chain represents the salmon, sea lice and soya plants? Tick (✓) one box.

What do the arrows in a food chain represent? Tick (✓) one box.

Some salmon are more resistant than other salmon to sea lice infections. Salmon farmers selectively breed salmon.

Salmon farmers select salmon that are most resistant to sea lice and breed these salmon together. What is the next stage in selectively breeding salmon that are resistant to sea lice? Tick (✓) one box.

When is the process of selective breeding finished? Tick (✓) one box.

Salmon that do not have sea lice are more profitable for the salmon farmer. Suggest one reason why.

What is a disadvantage of selectively breeding salmon? Tick (✓) one box.

Other fish farmers have produced genetically modified (GM) salmon.

GM salmon grow large enough to sell in 18 months. Non-GM salmon grow large enough to sell in 3 years. GM salmon need 25% less food than non-GM salmon to get to the same size.

Suggest two advantages of farming GM salmon instead of farming non-GM salmon.

GM salmon are often farmed a long distance from where wild, non-GM salmon live. What is an advantage of farming GM salmon a long distance from where wild salmon live? Tick (✓) one box.

Sea lice are small animals that feed on the skin and blood of salmon fish. Figure 3 shows sea lice attached to the skin of a salmon, Oncorhynchus keta.

What is the genus name of salmon?

Which domain are sea lice classified in?

Some salmon have genes that result in fewer sea lice attaching to the skin. Describe how fish farmers can selectively breed salmon that sea lice cannot attach to.

Explain the advantages to salmon farmers of producing salmon that do not have sea lice attached to their skin.

Explain the disadvantage of selectively breeding salmon. Do not refer to cost or to time in your answer.

The theory of evolution by natural selection was suggested by Charles Darwin in 1859. Evidence from fossils supports Darwin’s theory.

What evidence supports the theory of evolution by natural selection? Tick (✓) one box.

Figure 3 shows a fossil fly preserved in amber. The fossil formed when the amber solidified with the fly trapped inside.

Why has the fly been preserved? Tick (✓) one box.

Figure 4 shows a simplified evolutionary tree for the insect group of animals.

Figure 4

Which present day insect evolved first?

Animals A, B, C and D were ancestors of present day insects. Which animal is the most recent ancestor of both grasshoppers and beetles? Tick (✓) one box.

Name the group of present day insects which have wings which do not fold.

The house fly has the binomial name Musca domestica. Table 2 shows part of the classification for the house fly.

Complete Table 2. Choose answers from the box.

Carl Woese proposed the ‘three-domain system’ of classification. Which domain are insects in? Tick (✓) one box.

The polar bear is a mammal that lives in arctic habitats.

Complete Table 2 for the classification of the polar bear, Ursus maritimus.

Scientists have been measuring the area of sea ice in the Arctic since 1980. Figure 5 shows the area covered by sea ice every September.

Determine the annual rate of loss of sea ice between 1985 and 2017. A trend line has been drawn on Figure 5 to help you.

The total number of polar bears living on the arctic ice is not known. The hunting of polar bears has been banned or reduced in some areas. In some populations the average mass and height of polar bears has decreased. Polar bears eat seals. Seals live on the sea ice in winter and raise their pups there in early spring. In the summer seals live mainly in the sea catching fish to eat. Polar bears spend much of the year hunting seals on the sea ice and in the sea nearby. The sea ice area is at its lowest each year in September at the end of summer. The polar bears feed mainly in early spring, and again in autumn to build fat stores to survive the next winter. During the winter of 2017 scientists measured the metabolic rates of nine female polar bears and found them to be much higher than expected. Cameras attached to the female polar bears showed they had to swim long distances to find seals to eat.

Suggest why polar bears find it harder to catch seals in autumn than in spring.

Evaluate what might happen to the population of polar bears in the Arctic in the future.

A fossil was found in rocks. The rocks were formed from mud.

The fossil is of the fungus Ourasphaira giraldae.

What is the genus of the fungus?

Tick (✓) one box.

The mud around the fungus did not contain oxygen.

Which process did the mud around the fungus prevent?

Tick (✓) one box.

The fossilised fungus is estimated to be 890 000 000 years old.

What is 890 000 000 in standard form?

Tick (✓) one box.

Traditional classification divided organisms into kingdoms.

Who developed the traditional system of classification?

Tick (✓) one box.

More recent classification methods use a three-domain system.

What is the name of the domain the fungus Ourasphaira giraldae is classified in?

Tick (✓) one box.

Why has classification changed over time?

Tick (✓) one box.

The fungus Ourasphaira giraldae is now extinct.

Give two possible causes of extinction.

A fossil was found in rocks. The rocks were formed from mud. The fossil is of the fungus Ourasphaira giraldae.

What is the genus of the fungus?

Why was the mud important during the formation of the fossil? Tick (✓) one box.

The estimated age of the fossil is in the range from 8.9 × 10⁸ years old

to 1.1 × 10⁹ years old.

Calculate the size of the range of the estimated age of the fossil.

Humans did not exist when the fungus was alive. Suggest one other reason why an accurate estimation of when this species of fungus existed is not known.

Carl Woese developed the three-domain system of classification.

Fungi are not in the domain Archaea. Which domain are fungi classified in?

Which two characteristics are features of organisms in the domain Archaea? Tick (✓) two boxes.

Carl Linnaeus lived in the 1700s. Carl Linnaeus classified living things into groups depending on their appearance. Give three types of evidence that are used now to classify living things. Do not refer to appearance in your answer.

Figure 3 shows one species of bird on a bird feeder.

The birds use their beaks to reach nuts inside the bird feeder.

Figure 4 shows the mean beak length of this species of bird in the UK. This species of bird often visits bird feeders.

Determine the rate of change in beak length from 1984 to 2000. Use Figure 4.

Explain the process of evolution that could cause the trend in Figure 4.

Birds of this species:

• live for about 3 years

• produce up to 24 eggs every year.

Explain why evolution is easier to study in this species of bird than in humans.

Birds of this species are found in different parts of the world. Describe evidence that would show two individual birds are the same species.

Scientists believe that the first life on Earth was primitive anaerobic bacteria which first appeared billions of years ago.

Which domain of the three-domain classification system do these primitive anaerobic bacteria belong to?

Scientists have identified five periods of mass extinction since the fossil record began. Figure 6 shows the timeline of the five mass extinction events.

Ammonites were organisms that first appeared in the oceans 415 million years ago. Ammonites disappeared in the 5th mass extinction. Draw a horizontal line on Figure 6 to show the time period that ammonites existed on Earth. Label the line ‘ammonites’.

Another type of organism that existed in the oceans was called trilobites. Trilobites existed from 544 million years ago until 278 million years ago. How many more years did ammonites exist than trilobites?

There was an increase in the percentage of species which became extinct in the third mass extinction compared to the first mass extinction. Calculate the percentage increase.

Scientists have removed microorganisms from inside rocks in caves in Mexico. The microorganisms have been trapped there for between 10 000 and 50 000 years. The caves are dark, very hot, humid and acidic.

Why are these microorganisms called extremophiles? Tick two boxes.

The microorganisms have been inactive for thousands of years but the scientists have reactivated them. Figure 2 shows the results of enzyme analysis on four enzymes, A, B, C and D. Three of the enzymes were from microorganisms found in the soil near the caves. One of the enzymes was from a reactivated microorganism from the caves.

Which enzyme comes from the microorganism from the caves? Tick one box.

Give the reasons for your answer to question 03.2

Carl Woese developed the ‘three-domain system’ of classification. Describe the ‘three-domain system’ of classification.

Most of the microorganisms from the caves were classified as belonging to the Archaea domain of the ‘three-domain system’. Suggest why.