Date | May 2021 | Marks available | 1 | Reference code | 21M.1.SL.TZ1.25 |
Level | Standard level | Paper | Paper 1 | Time zone | Time zone 1 |
Command term | Question number | 25 | Adapted from | N/A |
Question
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
Markscheme
C
Examiners report
Syllabus sections
-
16N.1.SL.TZ0.19:
Lichens are returning to the forests of the industrial areas of the United Kingdom due to strict pollution control.
What is the expected outcome in the population of peppered moths (Biston betularia)?
A. Increased numbers of light-coloured peppered moths
B. Increased industrial melanism in peppered moths
C. Increased predation of peppered moths
D. Increased speciation of peppered moths -
22M.1.SL.TZ1.21:
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.
-
21N.1.SL.TZ0.21:
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.
- 21M.1.SL.TZ1.22: Which process results in decreased variation? A. Meiosis B. Mutation C. Sexual...
- 19M.1.SL.TZ2.27: What is the reason for antibiotics not damaging human cells? A. The dose is too small to be...
- 19N.2.HL.TZ0.3b: Outline how variation in organisms of the same species could lead to natural selection.
- 16N.1.SL.TZ0.21: What is the major contributor to the increase in antibiotic resistance in bacteria? A....
- 17N.1.SL.TZ0.21: What causes variation within a population? A. Fertilization and change in the...
- 17M.2.SL.TZ1.4b.ii: Suggest one type of additional evidence that could provide strong support for Turtles 3 as...
- 18M.2.SL.TZ1.1b: Suggest either one possible advantage or one disadvantage of having a banded shell, stating...
-
18M.1.SL.TZ1.20:
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.
-
18M.2.SL.TZ1.1a:
Determine the maximum percentage of yellow base colour shells found in woods.
- 18M.1.HL.TZ2.26: Which of the adaptations of flowers would be most successful for the survival of a...
- 17M.1.HL.TZ2.28: The photograph shows vegetation in a rocky area. Which characteristic of the plants...
-
18M.2.SL.TZ1.1c:
Using the data in the graph, distinguish between the distribution of C. nemoralis shells in woods and fields.
- 17M.1.SL.TZ2.27: The bacterium Neisseria gonorrhoeae causes infections related to the human reproductive...
- 18M.2.SL.TZ1.1f: Using the theory of natural selection, explain the differences shown in the graph between the...
- 18M.2.HL.TZ1.3a.ii: State the major chemical component of the shell in molluscs.
-
21N.2.SL.TZ0.3d:
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.
-
16N.2.HL.TZ0.4b:
Describe how variation contributes to evolution by natural selection.
- 20N.1.SL.TZ0.21: What would restrict evolution by natural selection, if a species only reproduced by...
- 20N.2.SL.TZ0.4b.ii: Explain how evolution by natural selection depends on mutations.
- 17M.1.SL.TZ1.20: A bacterial population with no resistance to an antibiotic may develop into a bacterial...
- 17M.1.SL.TZ1.21: Cladograms can be created by comparing DNA or protein sequences. The cladogram on the left is...
-
22M.2.SL.TZ1.7c:
Explain the development of antibiotic resistance in terms of natural selection.
-
22M.2.SL.TZ2.7b:
Explain how natural selection can cause traits such as drought resistance to develop in wild plants.
-
18M.2.SL.TZ1.1e:
Discuss whether there is evidence in the data that colour plays a role in the survival of the snails.
- 18M.2.SL.TZ1.1d: Deduce from the data in the graph which shell base colours are on average most and least...
-
22M.1.SL.TZ2.23:
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
- 17M.2.HL.TZ1.1f.ii: Suggest a reason for the greater expression of the gene for the urea transporter after an...
-
18M.2.HL.TZ1.2b:
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.
- 17M.1.HL.TZ1.17: A bacterial population with no resistance to an antibiotic may develop into a bacterial...
-
21M.2.HL.TZ1.7b:
Explain how genetic variation between the individuals in a species can be generated.
-
21M.2.SL.TZ2.6c:
Describe the risk to the human population of indiscriminate use of antibiotics.
- 17M.2.SL.TZ1.1c: Estimate how much smaller drilled oysters raised in seawater at a high CO2 concentration were...
- 17M.2.SL.TZ2.4b.ii: Some lice live in human hair and feed on blood. Shampoos that kill lice have been available...
- 19M.2.HL.TZ1.7b: Explain how natural selection can lead to speciation.
- 19M.2.SL.TZ1.7c: Explain how natural selection can lead to speciation.
- 17M.1.SL.TZ2.21: What is a direct consequence of the overproduction of offspring? A. Individuals become more...
-
18M.2.HL.TZ1.3a.i:
C. nemoralis is a mollusc. Identify two external features that distinguish this snail from an arthropod.
-
18M.2.SL.TZ2.6b:
Describe the evolution of antibiotic resistance in bacteria.
-
18M.1.HL.TZ2.28:
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.