The overall structure of the flipper of a whale, in terms of bones and muscles, is similar to the overall structure of the limb of a horse.  What are these structures referred to as?

:br

::indent
- A.$\hspace{1em}$ Ancestral structures

- B.$\hspace{1em}$ Convergent structures

- C.$\hspace{1em}$ Analogous structures

- D.$\hspace{1em}$ Homologous structures

Which of the following is the strongest evidence supporting the hypothesis that two populations are two different species?

:br

::indent
- A.$\hspace{1em}$ Allele frequencies differ between the two populations. 

- B.$\hspace{1em}$ The two populations are reproductively isolated.

- C.$\hspace{1em}$ The DNA sequence of some genes was found to be different.

- D.$\hspace{1em}$ The two populations are geographically isolated.

Which characteristic(s) is/are observed in both natural selection and selective breeding?

::indent
- :::tableoptions{col1="hide" col2="hide"}
    | | |
    | :-- | :-- |
    | I. | Favourable traits are selected|
    | II. | Increase in variation |
    | III. | Change is driven by the environment |
    :::

:br

::indent
- A.$\hspace{1em}$ I only

- B.$\hspace{1em}$ I and II only

- C.$\hspace{1em}$ I and III only

- D.$\hspace{1em}$ I, II and III 

Which of the following statement concerning analogous structures is/are correct?

::indent
- :::tableoptions{col1="hide" col2="hide"}
    | | |
    | :-- | :-- |
    | I. | They are formed through convergent evolution |
    | II. | They perform the same or similar functions in different organisms |
    | III. | They evolve from a common ancestor |
    :::

:br

::indent
- A.$\hspace{1em}$ II only

- B.$\hspace{1em}$ I and II only

- C.$\hspace{1em}$ II and III only

- D.$\hspace{1em}$ I, II and III

\[Maximum mark: 6\]

The male firefly (*P. pyralis*) signals to potential female mates by flashing its lights in specific patterns. Females will only respond to light patterns produced by their own species.

:::center
![BI0715A](question:d2b81121-d7da-4354-9e50-45429c3e396a)
:span[\[Source: Adapted from Gallagher, J. (2014, June 3). *File: Firefly - Photinus pyralis, Woodbridge, Virginia.jpg - Wikimedia ...* Wikimedia commons. Retrieved July 1, 2022, from https<NO LINK>://commons.wikimedia.org/wiki/File: Firefly_-_Photinus_pyralis,_Woodbridge,_Virginia.jpg Copyright under CC BY 2.0\]]{style="font-size:14px; line-height:1"}
:::

1. Identify the form of reproductive isolation that fireflies exhibit. Justify your answer.	 :marks[2]

2. Suggest **one** possible advantage of this mating ritual.  :marks[1]

3. All fireflies seen today have diverged from the same ancestral species. Explain how speciation is responsible for the large variety of firefly species.  :marks[3]


Shown in diagrams A and B are two pairs of similar structures. 

:::center
![BI0857](question:3cd298f7-34ad-4f4c-bc2b-6b7a3b43bf2f)
:span[\[© Revision Village 2022\]]{style="font-size:14px; line-height:1"}
:::

Which of the following statements correctly explain the structural similarities shown in diagrams A and B?

::indent
- :::tableoptions{col1="hide" col2="hide"}
    | | |
    | :-- | :-- |
    | I. | Structural similarities in diagram A are primarily due to random mutations, not common ancestry. |
    | II. | Structural similarities in diagram B are due to the fact they both perform similar functions. |
    | III. | Diagram A depicts analogous structures, and diagram B depicts homologous structures. |
    :::

:br

::indent
- A.$\hspace{1em}$ II and III only

- B.$\hspace{1em}$ I and II only

- C.$\hspace{1em}$ II only

- D.$\hspace{1em}$ I, II and III

It is thought that the Congo River divided a population of the common ancestor of bonobos (*Pan paniscus*) and chimpanzees (*Pan troglodytes*), resulting in geographic isolation.  Which correctly pairs theoretical selection pressures and consequent adaptations of the two populations?

:br

![BI0859](question:e9f0bfbf-b64e-4476-8fa3-e01eb43f2eb1)

What sequence of events usually occur during the process of speciation?

:br

::indent
- A.$\hspace{1em}$ Reproductive isolation → one species becomes two species → random mutations

- B.$\hspace{1em}$ Random mutations → reproductive isolation → one species becomes another species

- C.$\hspace{1em}$ Geographic isolation → reproductive isolation → one species becomes another species

- D.$\hspace{1em}$ Geographic isolation → reproductive isolation → one species becomes two species

\[Maximum mark: 10\]

The graph shows the changes in the population of pale (mostly white) and dark (mostly black) peppered moths (*Biston betularia*) during and post the industrial revolution.

:::center
![BI1291](question:d3574329-664b-4912-804c-f9a20dfa2636)
:span[\[© Revision Village 2023\]]{style="font-size:14px; line-height:1"}
:::

:br 

The image shows the phenotype of pale and dark moths on white tree bark.

:::center
![BI1291b](question:2cab37cd-63f2-45dd-b597-e0d9ac454ded)
:span[\[Source: Adapted from Bedin, T. (2020, May 26). *Tilpasning og evolusjon - natural science (PB) - NDLA. ndla.no*.  Retrieved October 02, 2023, from https<no link>://ndla.no/en/subject:1:bb834c76-d1e4-46c4-8c0a-8f978bd2c956/topic:6:f604b380-5cdb-4227-885e-bc9b57cb3237/topic:3:aa019f6a-a569-4491-b0d2-c8d2df21733f/resource:09fc6c1a-eaa1-4901-b2ae-ee5e7ce1900c. Copyright free\]]{style="font-size:14px; line-height:1"}
:::

1. Distinguish between the changes in the numbers of pale and dark moths shown in the graph.		:marks[2]


2.
    1. Outline how the trends in the graph can be explained by natural selection.	 :marks[3]

    2. Suggest a technique a group of students could use to compare the population sizes of peppered moths between a deciduous and a coniferous wood.		:marks[1]

3. Calculate the percentage increase in dark-coloured moths between 1850 and 1900.		:marks[1]

4. Draw a line on the graph, predicting how the number of pale moths would have changed, if the industrial revolution did not happen.	:marks[1] 

5. In addition to collecting data such as that shown in the graph, scientists rely on various forms of evidence to explore the concept of evolution. State two other forms of evidence that supports the theory of evolution.	:marks[2]




Which pair of structures would be considered analogous?

:br 

:::center
![BI1154](question:b41d5e40-835b-4b46-8022-7f52ad7a8980)
:span[\[© Revision Village 2023. Created with BioRender.com\]]{style="font-size:14px; line-height:1"}
:::

Which of the following provides evidence for evolution through selective breeding?

::indent
- :::tableoptions{col1="hide" col2="hide"}
    | | |
    | :-- | :-- |
    | I. | Phenotypic variation in the domesticated dog (*Canis familiaris*) has increased significantly as a result of humans selecting desirable traits. |
    | II. | Crop yield in domesticated crop plants is significantly greater than their wild relatives. |
    | III. | *Homo sapiens* in many parts of the world have alleles that provide resistance to diseases endemic to their region. |
    :::

:br

::indent
- A.$\hspace{1em}$ I and II only

- B.$\hspace{1em}$ I and III only

- C.$\hspace{1em}$ III only

- D.$\hspace{1em}$ I, II and III

The base sequence between two species was found to be 78% the same, while the order of amino acids found in the same cell types between two species was 82% the same.  What may be the reason for this?

:br

::indent
- A.$\hspace{1em}$ The genetic code is degenerate.

- B.$\hspace{1em}$ Mutations occur more frequently in DNA that codes for proteins.

- C.$\hspace{1em}$ Techniques used to analyse base sequences of DNA are less reliable.

- D.$\hspace{1em}$ The genetic code is universal.

\[Maximum mark: 16\]

1. Outline three sources which provide evidence for evolution.	:marks[3]

2. Describe how both bats and butterflies have wings.		:marks[5]

3. Explain the process of speciation with at least one named example. 	:marks[7]

\[Maximum mark: 10\]

A study has been conducted on the effect of hormonal contraception pollution on the mating calls of the adult male African clawed frog (*Xenopus laevis*). The spectrogram shows the frequency and pitch of clicks (mating call) of control *X.laevis* and those exposed to oestrogen.

:::center
![BI0813ai](question:667a05b0-9823-4179-8462-aeb8533d89e6)
![BI0813aii](question:d72923f4-70b3-4902-9dca-a7691677d6e1)
:span[\[Source: Adapted from Hoffmann, F., & Kloas, W. (2012, February 15). *Estrogens can disrupt amphibian mating behavior*. PLOS ONE. Retrieved May 13, 2023, from https<NO LINK>://journals.plos.org/plosone/article?id=10.1371%2Fjournal.pone.0032097.  Copyright under CC BY 4.0\]]{style="font-size:14px; line-height:1"}
:::

1. Distinguish between the clicks in the spectrogram between the control *X. laevis* and the *X. laevis* treated with oestrogen in 1 second.			:marks[2]

:br 

The graph shows the average duration of the *X. laevis* mating calls when exposed to the hormone oestrogen.

:::center
![BI0813b](question:e40617ac-738d-43f5-b7d7-96a0d5c44a0d)
:span[\[Source: Adapted from Hoffmann, F., & Kloas, W. (2012, February 15). *Estrogens can disrupt amphibian mating behavior*. PLOS ONE. Retrieved May 13, 2023, from https<NO LINK>://journals.plos.org/plosone/article?id=10.1371%2Fjournal.pone.0032097.  Copyright under CC BY 4.0\]]{style="font-size:14px; line-height:1"}
:::

2. Describe the effect of oestrogen on the duration of the mating call shown in this study.		:marks[2]

3. Explain why it is important to have the *X.laevis* control group.		:marks[1]

4. Identify the independent variable in this study.	:marks[1]

5. 
    1. Predict the relative reproductive success of *X.laevis* exposed to 29.6 ngL:sup[-1] of oestrogen.			:marks[1]

    2. Outline the possible consequences of oestrogen exposure on *X. laevis*.:marks[3]

\[Maximum mark: 6\]

Below is a diagram that outlines the bone structure of four different animal species. These structures all evolved from a common ancestor with a pentadactyl (5-digit) limb.

:::center
![image](question:f6014efd-35d1-4a93-af4c-2c6a333b810b)
:span[\[Source: Adapted from Волков Владислав Петрович.  2011, January, 1. *Homology*.  Retrieved December 9, 2022 from https<NO LINK>://en.wikipedia.org/wiki/Homology_(biology)#/media/File: Homology_vertebrates-en.svg. CC BY-SA 4.0\]]{style="font-size:14px; line-height:1"}
:::

1. State the term used to describe anatomical features found in different species that share a common ancestor.  :marks[1]

2. Bones are living tissues that require nutrients that are transported in the blood.  Outline how the structure of capillaries makes them well-adapted for the exchange of nutrients.  :marks[2]

3. Compare and contrast natural selection and selective breeding.  :marks[3]

Which statement best illustrates the process of evolution?

:br

::indent
- A.$\hspace{1em}$ A horse that increases its maximum running speed has faster offspring.

- B.$\hspace{1em}$ A random mutation gives resistance to a disease and spreads in the population.

- C.$\hspace{1em}$ Mutations occur as needed to increase fitness in individuals and populations.

- D.$\hspace{1em}$ The most complex organisms are the most evolved.

\[Maximum mark: 16\]

Chimpanzees (*Pan troglodytes*) and Bonobos (*Pan paniscus*) are humans’ closest living primate relatives. The chimpanzee and bonobo genomes are approximately  98.7 % identical to the human genome. However, studies have shown that chimpanzees have evolved to use and make tools for foraging food, whilst bonobos use tools less frequently and diversely than chimpanzees. The map shows their distribution in Western and Central Africa. 

:::center
![BI1421a](question:bb9ae1a9-328c-4780-a74b-19e10239746a)
:span[\[Source: Adapted from Guy, Cp. (2016, May 24). *File: Bonobo vs chimp.png* - Wikimedia Commons. Wikimedia commons. Retrieved January 12 , 2024 from URL https<no link>://commons.wikimedia.org/wiki/File: Bonobo_vs_chimp.png. Copyright under CC BY 4.0\]]{style="font-size:14px; line-height:1"}
:::

1. State the genus of chimpanzees.		:marks[1]

2. Researchers use the distribution of chimpanzees and bonobos as an example of ‘natural selection that has resulted in speciation’. Explain why this is.	:marks[2]

3. Suggest what evidence researchers may have discovered to support the hypothesis that chimpanzees and bonobos share a recent common ancestor.		:marks[1]

:br 

The chart shows the mean diet compositions of chimpanzees and bonobos.

:::center
![BI1421c](question:4af9abb7-2574-46b3-a363-896c87b78616)
:span[\[Source: Adapted from Masi, S. (2023, September 20). Tool use, or not tool use, that is the question: *Is the necessity hypothesis really inconsequential for the African great apes?*. Frontiers. Retrieved January 12 , 2024 from URL https<no link>://www<no link>.frontiersin.org/articles/10.3389/fmamm.2023.1281030/full. Copyright under CC BY 4.0\]]{style="font-size:14px; line-height:1"}
:::

4. Compare and contrast the diets of chimpanzees and bonobos.:marks[3]

:br 

The chart shows the mean number of microorganisms that aid in the digestion of cellulose and fibre in chimpanzees and bonobos. 

:::center
![BI1421E](question:2dc3031f-c8d3-427f-80ec-2ea794101382)
:span[\[Source: Adapted from Masi, S. (2023, September 20). *Tool use, or not tool use, that is the question: Is the necessity hypothesis really inconsequential for the African great apes?*. Frontiers. Retrieved January 12 , 2024 from URL https<no link>://www<no link>.frontiersin.org/articles/10.3389/fmamm.2023.1281030/full. Copyright under CC BY 4.0\]]{style="font-size:14px; line-height:1"}
:::

5. Suggest why the presence of microorganisms that digest cellulose and fibre may be more beneficial for bonobos than chimpanzees.	:marks[1]

6.
    1. State the monomer product of cellulose digestion.	:marks[1]

    2. State what role the substance named in part (i) plays in energy production.			:marks[1]

7. Gorillas live to the North of the Congo River but not to the South. Gorillas are herbivores that mainly eat leaves and leafy plants. Scientists suggested competition for food may have acted as a selection pressure for the use of tools by chimpanzees. Suggest how the data in the previous graphs support this claim.		:marks[2]

:br

The graphs below compare the hourly frequency of play session invitations for bonobos and chimpanzees, over developmental stages: infants, teenagers, and adults.  A play session invitation is when an animal initiates a play session by inviting another animal to play.  The bold horizontal line represents the median and the vertical length of the central box represents the interquartile range.

:::center
![BI1421h](question:c1c78385-907f-4d85-b394-e714b1970cb1)

![BI1421hii](question:50c4258f-ee88-464b-bebc-d61c84098cbf)
:span[\[Source: Adapted from Palagi, E., & Cordoni, G. (2012, December 26). *The right time to happen: Play developmental divergence in the two pan species*. PLOS ONE. Retrieved January 12 , 2024 from URL https<no link>://journals.plos.org/plosone/article?id=10.1371%2Fjournal.pone.0052767#s3. Copyright under CC BY 3.\]]{style="font-size:14px; line-height:1"}
:::

8. Deduce with a reason whether bonobos or chimpanzees have more play session invitations as teenagers.	 :marks[1]

:br 

The following graph compares the number of play sessions that escalate into overt aggression in bonobos and chimpanzees, over the developmental stages.

:::center
![BI1421hiii](question:a16f5dac-70ab-4e6d-98ae-1a5337197297)
:span[\[Source: Adapted from Palagi, E., & Cordoni, G. (2012, December 26). *The right time to happen: Play developmental divergence in the two pan species*. PLOS ONE. Retrieved January 12 , 2024 from URL https<no link>://journals.plos.org/plosone/article?id=10.1371%2Fjournal.pone.0052767#s3. Copyright under CC BY 3.0\]]{style="font-size:14px; line-height:1"}
:::

9. Calculate the percentage increase in the median between play sessions that escalate into aggression in infant and teenage chimpanzees.	:marks[1]

10. Using the evidence provided and your own knowledge, suggest why chimpanzees tend to be more aggressive than bonobos.		:marks[2]




Darwin/Lamarck, Homologous & Analogous Structures, Convergent Evolution, Speciation, Reproductive Isolation

SL - 2025

Unity & Diversity

A1.1 Water

BI0177

BI1046

BI0836

BI0837

BI0181

BI0834

BI0835

BI0769

A1.2 Nucleic Acids

BI0040

BI0047

BI0321

BI0840

BI0841

BI1048

BI1047

A2.2 Cell Structure

BI0002

BI0532

BI0752

BI0001

BI0756

BI0804

BI1049

A3.1 Diversity of Organisms

BI0102

BI1023

BI1024

BI1025

BI0081

BI1021

BI0200

BI1051

A4.1 Evolution & Speciation

BI0855

BI0856

BI0857

BI0858

BI0862

BI0813

BI0237

A4.2 Conservation of Biodiversity

BI0903

BI0901

BI0902

BI0907

BI0908

BI0910

BI0911

Medium of Life, Polarity, Hydrogen Bonding, Adhesion, Cohesion, Solvent Properties, Physical Properties, Consequences

Water

BI0182

BI0183

BI0178

BI0186

BI0668

BI0187

BI1224

BI1320

BI1424

BI1011

BI1012

BI1010

BI1015

BI1014

BI1537

Nucleotides, Bases, RNA & DNA Structure, Antiparallel, Complementarity, Conservation of Code

Nucleic Acids

BI0330

BI0045

BI0421

BI0043

BI0038

BI1166

BI1221

BI0897

BI1382

BI1394

BI0541

BI0039

Prokaryote & Eukaryote Cell Structure, Functions of Life, Light & Electron Microscopy, Atypical Cells

Cell Structure

BI0198

BI0392

BI0391

BI0397

BI0399

BI0390

BI0531

BI0009

BI0394

BI0799

BI0492

BI0575

BI0798

BI0189

BI0072

BI0395

BI0816

BI0494

BI0398

BI0400

BI0572

BI0560

BI0753

BI0562

BI0534

BI1136

BI1137

BI1197

BI0833

BI1223

BI1258

BI1259

BI1542

BI1263

BI1322

BI0201

BI1440

Variation, Species, Linnaeus, Binomial System, Speciation, Karyotyping, Genomes

Diversity of Organisms

BI0250

BI0101

BI0712

BI0197

BI0190

BI1022

BI1220

BI1227

BI1375

BI1384

BI1395

BI1421

Evolution & Speciation

BI0861

BI0715

BI0859

BI0860

BI1154

BI1232

BI1316

BI1377

BI1291

BI1512

Ecosystem/Species/Genetic Diversity, Anthropogenic Extinction, Ecosystem Loss, Biodiversity Crisis, EDGE programme

IB Biology SL - 2025 - Questionbank

A4.1 - Evolution & Speciation

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