Which statement is **not** true about the genome?

:br

::indent
- A.$\hspace{1em}$ The human genome is organised into chromosomes.

- B.$\hspace{1em}$ Each liver cell contains a full copy of the genome.

- C.$\hspace{1em}$ Organisms of the same species share most of their genome.


- D.$\hspace{1em}$ All the information carried by the genome is expressed in each cell.

The scientific name for the little spotted kiwi is *Apteryx owenii*. Which of the species below is most closely related to the little spotted kiwi?

:::center
![BI1227](question:6faa3925-6492-47de-90a7-925e1e8a2859)
:span[\[Source: Adapted from Lapsley Miller, J. (2023, August 28). *Little Spotted Kiwi*. Wikipedia. Retrieved September 13, 2023, from https<NO LINK>://en.wikipedia.org/wiki/Little_spotted_kiwi.  Copyright under CC BY-SA 4.0\]]{style="font-size:14px; line-height:1"}
:::

:br

::indent
- A.$\hspace{1em}$ *Apteryx australis*

- B.$\hspace{1em}$ Little spotted pardalote

- C.$\hspace{1em}$ *Owenii apteryx*

- D.$\hspace{1em}$ *Neognathae owenii*

What is the best definition for a species?

:br

::indent
- A. $\hspace{1em}$ A group of individuals living in a defined area.

- B. $\hspace{1em}$ A group of individuals of the same species living and interacting with one another in a given area.

- C. $\hspace{1em}$ A group of individuals living in a given area and interacting within the environment.

- D. $\hspace{1em}$ A group of individuals that can interbreed and produce fertile offspring.

Biologists use the binomial naming system to name every organism on the planet. The binomial name for the platypus is *Ornithorhynchus anatinus*. Which statement(s) below are true for the binomial naming system and the platypus?

::indent
- I. $\hspace{1em}$	The genus for the platypus is *Ornithorhynchus*.
- II. $\hspace{.7em}$	The binomial naming system is based on an international agreement 
between scientists.
- III. $\hspace{.4em}$ 	The name, *Ornithorhynchus anatinus* is unique to platypus species.

:br

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

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


The table shows the nucleotide base sequence and genome size (number of base pairs, bp) for different species.

:::center
![BI0840](question:e50f84c7-31b6-4770-bdd6-a3ae9bb089f4)
:span[\[©Revision Village 2023. \]]{style="font-size:14px; line-height:1"}
:::
Which conclusion can be drawn, based on the table?

:br

::indent
- A.$\hspace{1em}$ Genome size is proportional to the size of the species.


- B.$\hspace{1em}$ The more closely related two species are, the more similar their base sequences.


- C.$\hspace{1em}$ Humans have more genes than chimpanzees, mice and horses.


- D.$\hspace{1em}$ The base sequence in the table for humans and chimpanzees is the same, therefore they have an identical genetic code.



Which of the following is the correct format for species names according to the binomial naming system? 

:br

::indent
- A.$\hspace{1em}$ Genus + Species

- B.$\hspace{1em}$ Genus + species

- C.$\hspace{1em}$ *Genus* + *species*

- D.$\hspace{1em}$ *Genus* + *Species*

Which of the following is true for the biological species concept? 

:br

::indent
- A.$\hspace{1em}$ Organisms within the same species can interbreed to produce fertile offspring

- B.$\hspace{1em}$ Organisms within the same species can interbreed to produce infertile offspring

- C.$\hspace{1em}$ Species are groups of organisms with shared traits

- D.$\hspace{1em}$ Species are groups of organisms without shared traits

The okapi looks like a small-sized giraffe and has stripes that resemble the zebra. It lives in the Ituri Forest in the Democratic Republic of the Congo. Okapis eat the leaves and buds of trees they can reach. They also graze on grass and ferns and eat fruit. Okapis tend to be solitary animals and the mother gives birth to one offspring which continues to be dependent on the mother’s milk for six months. When they are four to five years old, they are mature and can breed, but only with other okapis.

Which of the following statements is applicable to the okapi?

::indent
- :::tableoptions{col1="hide" col2="hide"}
  | | |
  | :-- | :-- |
  | I. | Okapi is a hybrid of a giraffe and a zebra |
  | II. | Okapi is an herbivore |
  | III. | Okapi is its own species |
  :::

:br

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

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

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

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

The table shows factors that can result in speciation. Which word is matched to the correct definition?

:br

:::tableoptions{col1="hide"}
| | Word | Definition |
| --- | :-: | :-: |
| A.$\hspace{1em}$ | Polyploidy | Having two complete sets of chromosomes |
| B.$\hspace{1em}$ | Sexual reproduction | The combining of genetic information from two individuals |
| C.$\hspace{1em}$ | Reproductive isolation | Species breeding to produce infertile offspring |
| D.$\hspace{1em}$ | Mutations | Random changes to the amino acid sequence |
:::

Which of the following statement(s) is/are true for the genome? 

::indent
- :::tableoptions{col1="hide" col2="hide"}
    | | |
    | :-- | :-- |
    | I. | The genome is all the genetic information of an organism.  |
    | II. | Genomes within a species are identical in size. |
    | III. | Genomes within a species vary in base sequence. |
    :::

: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

The following table shows the diploid chromosome number of a range of species.

:br

| Organism | Diploid chromosome number 
| :-: | :-: | 
| Yellow fever mosquito \(*Aedes egypti*) | 6 | 
| Fruit fly (*Drosophila melanogaster*) | 8 |
| Spinach (*Spinacia oleracea*)  | 12 | 
| Carrot (*Daucus carota*) | 18 |
| Rice (*Oryza sativa*) | 24 |
| Giraffe (*Giraffa camelopardalis*) | 30 |
| Giant panda (*Ailuropoda melanoleuca*)| 42 |

:br

Which of these statements is correct?

:br
::indent
- A. $\hspace{1em}$ The giant panda has more genes than the other species 
- B. $\hspace{1em}$ The yellow fever mosquito has the fewest genes from these species
- C. $\hspace{1em}$ The gametes of carrots have 18 chromosomes
- D. $\hspace{1em}$ The chromosome number is a characteristic of a species


How are the chromosomes in a karyogram ordered?

:br

::indent
- A.$\hspace{1em}$ By analogous pairs

- B.$\hspace{1em}$ By number of genes

- C.$\hspace{1em}$ By size

- D.$\hspace{1em}$ By position of the centromeres

\[Maximum mark: 16\]

1. Outline the different uses of karyograms. :marks[3]	

2. Distinguish between cells with haploid and diploid nuclei. :marks[4]

3. Compare and contrast different types of chromosomes. :marks[8]

\[Maximum mark: 4\]

The table below shows the genome size and diploid chromosome numbers of five different species.

:br
:::center
| Organism | Chromosome number | Genome size (millions of base pairs)
| :-: | :-: | :-: |
| T4 phage (virus) | Single piece of DNA | 0.17 |
| *Escherichia coli* (bacteria) | 1 | 5 |
| *Drosophila melanogaster* (fruit fly) | 8 | 140|
| *Homo sapiens* (human)| 46 | 3,000 |
| *Paris japonica* (woodland plant)| 40 | 150,000 |
:::

:br
1. Evaluate the evidence from the table in relation to the statement that “organisms with a higher number of chromosomes do not always have more base pairs”. :marks[2]

2. Discuss the data as evidence for the notion that increased genome size means that the organism is more complex. :marks[2]


The image shows a cladogram for several species of hamster.

:::center
![BI1375](question:f8f32c6b-0ecc-4be9-ac60-535e09501347)
:span[\[Source: Adapted from Michaplot. (2012, January 4). *File: PhodopusCladogram.jpg*. Wikipedia. Retrieved December 04, 2023 from URL  https<no link>://en.wikipedia.org/wiki/File:PhodopusCladogram.jpg. Copyright under CC BY 3.0\]]{style="font-size:14px; line-height:1"}
:::

:br 

1. State what is represented by the letter **X**. :marks[1]

2. Other than their positions on the cladogram, explain what information indicates that *Phodopus campbelli* and *Phodopus sungorus* are closely related.	:marks[1]

3. Modern hamsters have small, furry ears. The common ancestor of the hamsters in the cladogram has been hypothesised to have large, furry ears. Suggest how natural selection explains these changes.		:marks[3]

\[Maximum mark: 7\]

*Ammophila arenaria* (Marram grass), pictured below, is plant species that is often found on sand dunes. 

:::center
![BI1021A](question:30736373-9328-49f9-95e6-c476e1a892d2)
:span[\[Source: Agnieszka K., Nova. (2020). *File: Ammophila arenaria Piaskownica zwyczajna* 2020-06-29 04.jpg
.Wikimediacommons. Retrieved July 29, 2023, from https<NO LINK>://commons.wikimedia.org/wiki/File: Ammophila_arenaria_Piaskownica_zwyczajna_2020-06-29_04.jpg.  Copyright under CC BY-SA 4.0
\]]{style="font-size:14px; line-height:1"}
:::

1.
    1. Identify the genus to which *Ammophila arenaria* belongs. :marks[1]

    2. State the naming system used to name *Ammophila arenaria*. :marks[1]

    3. State the term used to describe the differences between organisms, which is used as the basis for the naming system in part (ii).  :marks[1]

    4. Describe how the genome within a species could vary.	 :marks[2]

2. Compare and contrast the morphological and biological species concepts. 	:marks[2]

What type of human cell does the following karyogram represent?

:::center
![BI0190](question:8fe74a9b-93cc-4365-80da-a04e030a1103)
:span[\[Source: Adapted from Abedi M., Salmaninejad A. and Sakhinia E. (13th November 2017). *File: Peripheral-blood-karyotype-result-belonging-to-the-subject-compatible-with-48-XYYY.png.* Wikimedia commons. Retrieved 15th May 2022 from https<nolink>://commons.wikimedia.org/wiki/File: Peripheral-blood-karyotype-result-belonging-to-the-subject-compatible-with-48-XYYY.png. Copyright under Creative Commons 4.0 International \]]{style="font-size:14px; line-height:1"}
:::

:br

::indent

- A. $\hspace{1em}$ Sperm

- B. $\hspace{1em}$ Egg
- C. $\hspace{1em}$ Brain cell
- D. $\hspace{1em}$ Skin cell


\[Maximum mark: 16\]

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]




The following table shows the approximate number of protein-encoding genes found in various species. What can be concluded from these findings?

:::tableoptions
| Species | Approximate number of protein-encoding genes|
| :-: | :-: |
| *Drosophila melanogaster* (fruit fly)| 14,000 |
| *Oryza sativa* (rice) | 51,000 |
| *Gallus gallus* (chicken) |20,000-23,000 |
| *Homo sapiens* (human) | 20,000-25,000 |
:::

::indent
- :::tableoptions{col1="hide" col2="hide"}
    | | |
    | :-- | :-- |
    | I. | The number of genes is not a good indicator of organism complexity. |
    | II. | Chickens may have more genes than humans. |
    | III. | The number of base pairs in the rice genome is greater than in the other species. |
    :::

:br

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

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

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

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

\[Maximum mark: 16\]

1. Outline the binomial naming system and its importance. 	:marks[4]

2. Explain how a sample of cells taken from a foetus can be used to determine whether the foetus will be biologically male or biologically female at birth.		:marks[4]

3. Outline the outcomes of the human genome project and their impacts on different fields of science. :marks[7]

This table shows the estimated number of genes in *E. coli* bacteria, fruit flies, mice, humans, and rice.

:::center
| Species | Estimated number of genes |
| :-- | :-- |
| *E.coli* (bacteria species) | 4,000 |
| *Drosophila melanogaster* (fruit fly) | 13,000 |
| *Canis lupis familiaris* (dog) | 20,000 |
| *Homo sapiens* (humans) | 30,000 |
| *Oryza sativa* (rice) | 40,000 |
:::

What can you conclude from the above information?

:br

::indent
- A.$\hspace{1em}$ Species in the same kingdom of life have a similar number of genes

- B.$\hspace{1em}$ Different species have different numbers of genes

- C.$\hspace{1em}$ More complex species have more genes

- D.$\hspace{1em}$ The number of genes is not a characteristic of a species

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

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

Diversity of Organisms

BI0250

BI0101

BI0712

BI0197

BI0190

BI1022

BI1220

BI1227

BI1375

BI1384

BI1395

BI1421

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

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

A3.1 - Diversity of Organisms

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