The graph shows the proportion of a bacterial population of Neisseria gonorrhoeae, displaying resistance to the antibiotic tetracycline.

[Source: © All rights reserved. Canadian Antimicrobial Resistance Surveillance System Report, 2016. Public Health Agency of Canada. Adapted and reproduced with permission from the Minister of Health, 2022.]

What can be deduced from this graph?

A. Bacteria with beneficial adaptations survive and pass on their genes.

B. Immunity to tetracycline is triggered by over-use of the antibiotic.

C. Genetic variation in this bacterial population is increasing.

D. Use of tetracycline inhibits the growth of antibiotic-resistant N. gonorrhoeae.

Scientists studying ground finches (Geospiza fortis) on the island of Daphne Major in Galapagos found great differences in the shapes of the beaks.

[Source: Public domain.]

What is the explanation for this variation in beak shape between the birds?

A. Ground finches grow larger beaks if there is competition for food.

B. They belong to different species.

C. They are adapted for different diets.

D. The more a beak is used by a ground finch, the larger it becomes.

Balkan green lizards, Lacerta trilineata, living in mainland Greece eat mostly insects but also small amounts of plants. The same species living on Greek islands (where insects are scarce) show a greater percentage of those physical traits useful for eating plants than the mainland lizards.

[Source: Penny Turner/Wikimedia file licensed under CC BY-SA 4.0
https://creativecommons.org/licenses/by-sa/4.0/deed.en]

What is the biological explanation for these observations?

A. Variation in each lizard population allowed adaptation to occur.

B. Lizards migrated to areas where they were better adapted.

C. Lizards on the islands diverged due to lack of interbreeding with the mainland population.

D. Homologous structures have prevented separate species from evolving.

Determine the maximum percentage of yellow base colour shells found in woods.

On the islands of the St Kilda chain, off the coast of Scotland, there are small birds called St Kilda wrens (Troglodytes troglodytes hirtensis). They look similar to wrens on the mainland of Scotland (Troglodytes troglodytes indigenus), but they are larger and there are differences in the colour of their feathers.

What is the most likely explanation for these differences?

A. Convergent evolution

B. Stabilizing natural selection

C. Gradual divergence

D. Exposure to similar selection pressure

Using the data in the graph, distinguish between the distribution of C. nemoralis shells in woods and fields.

All of the leaves in the image are from Solanum, a wild genus of tomato.

[Source: Courtesy: National Science Foundation, Credit Leonie Moyle.]

State one cause of variation in a plant such as the tomato.

Describe how variation contributes to evolution by natural selection.

Explain the development of antibiotic resistance in terms of natural selection.

Explain how natural selection can cause traits such as drought resistance to develop in wild plants.

Discuss whether there is evidence in the data that colour plays a role in the survival of the snails.

Which factor(s) would favour evolution by natural selection?

I. Long lifespans

II. Favourable characteristics acquired by individuals during their lifetime

III. Variation within a species

A. II only

B. III only

C. I and II

D. I and III

Birds, bats and humans are all vertebrates with pentadactyl limbs. Birds and bats use their forelimbs to fly whereas humans can use them to lift and manipulate objects. Outline how the bird, bat and human forelimb can be used to illustrate the concept of homologous structures.

Explain how genetic variation between the individuals in a species can be generated.

Describe the risk to the human population of indiscriminate use of antibiotics.

C. nemoralis is a mollusc. Identify two external features that distinguish this snail from an arthropod.

Describe the evolution of antibiotic resistance in bacteria.

Prickly pear cactus plants are well adapted to desert conditions. The stems are the flattened structures visible in the image and the leaves are reduced to spines. The white spots in the image are groups of spines.

[Source: Stan Shebs/Wikimedia. File licensed under CC BY-SA 3.0 (https://creativecommons.org/licenses/by-sa/3.0/)]

Which characteristic describes the advantage of one of their adaptations?

A. Leaves are reduced to spines to lose less carbon dioxide.

B. Spines increase surface area for more photosynthesis.

C. Stems are flattened to allow more water to be stored between periods of rain.

D. Waxy cuticle on the stems is very thin to allow rapid absorption of rain.