Which of the following provides evidence for a higher level of biodiversity now compared to any time in the past?

:br

::indent
- A.$\hspace{1em}$ Changing levels of atmospheric carbon dioxide

- B.$\hspace{1em}$ The fossil record

- C.$\hspace{1em}$ A decrease in the rate of evolution

- D.$\hspace{1em}$ Decreased levels of speciation



Which is **not** a cause of the current biodiversity crisis?

:br

::indent
- A.$\hspace{1em}$ Decreased urbanisation

- B.$\hspace{1em}$ The widespread use of vaccines

- C.$\hspace{1em}$ Increased air travel

- D.$\hspace{1em}$ Increased transmission of diseases



Which statement(s) are possible solutions to the biodiversity crisis?

::indent
- :::tableoptions{col1="hide" col2="hide"}
    | | |
    | :-- | :-- |
    | I. | Promoting rewilding projects |
    | II. | Recycling and reusing products |
    | III. | Increase meat consumption |
    :::

:br

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

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

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

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


Which is **not** a cause of anthropogenic species extinction?


:br

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

- B.$\hspace{1em}$ Deforestation

- C.$\hspace{1em}$ Introduction of new diseases

- D.$\hspace{1em}$ Asteroids


The image shows changes in coverage to mixed dipterocarp forests in Southeast Asia over the last 100 years.  
Which is not a factor that contributed to these changes? 

:::center
![BI0904_A4.2](question:ede73a61-24fa-43b8-b1ae-1135b7e67858)
:span[\[Source: Adapted from San Jose. (2006, February 8). File: map of east asia.png - wikimedia commons. Wikimedia commons. Retrieved July 10, 2023 from URL https<NO LINK>://commons.wikimedia.org/wiki/File: Map_of_East_Asia.png. Copyright under CC BY 3.0\]]{style="font-size:14px; line-height:1"}
:::

:br

::indent
- A.$\hspace{1em}$ Building of new roads to mining sites

- B.$\hspace{1em}$ Poaching of endangered species

- C.$\hspace{1em}$ Planting of rubber plantations

- D.$\hspace{1em}$ Building of hydroelectric dams


\[Maximum mark:10\]

The image shows the extinct North Island giant moa (*Dinornis novaezealandiae*), a flightless bird that was native to New Zealand. The Moa became extinct in the last 600 years, during the current sixth mass extinction. 

:::center
![BI0910](question:b1dfd7ea-6184-436b-992e-995929493172)
:span[\[Source: Adapted from Michael, B. H. (2012). File: Euryapteryx.jpg - Wikimedia Commons. Wikimedia commons. Retrieved July 21, 2023 from URL https<NO LINK>://
commons.wikimedia.org/wiki/File: Euryapteryx.jpg. Copyright under CC BY 3.0
\]]{style="font-size:14px; line-height:1"}
:::

1. 
    1. State the key difference between the current sixth mass extinction and the previous mass extinctions.  :marks[1]

    2. State one possible cause of the extinction of the Moa.  :marks[1]

2. 
    1. Outline the physical evidence scientists have collected indicating that the Moa existed.  :marks[1]

    2. In the past, scientists thought that the kiwi (*Apteryx haastii*), a flightless bird based in New Zealand, was the Moa’s closest living relative.  However, this has been disproven. State what evidence scientists may have found to disprove this relationship.  :marks[1]

    3. The Moa’s closest living relatives are the South American Tinamou (*Tinamus major*), which have the ability to fly. Explain why these birds are less likely to go extinct than the Moa.  :marks[1]

3. Evidence suggests that the Tinamou and Moa shared a common ancestor, but they evolved independently from each other when they were geographically isolated millions of years ago. Explain the evolution of the Tinamou with reference to natural selection.    :marks[3]

3. Another animal at risk of extinction is the Javan rhinoceros (*Rhinoceros sondaicus*), shown in the image below. There are thought to be fewer than 80 in the world. Suggest two methods scientists could use to prevent its extinction, with a reason for each.    :marks[2]

:::center
![BI0910b](question:d8f49dc3-c88c-451b-96e7-b2940ee2bce2)
:span[\[Source: Adapted from Nelson, S. (2012, July 20). Category: Rhinoceros Sondaicus. Wikimedia Commons. Retrieved July 21, 2023 from URL https<NO LINK>://
commons.wikimedia.org/wiki/Category: Rhinoceros_sondaicus. Copyright under CC BY 3.0
\]]{style="font-size:14px; line-height:1"}
:::

Which definitions are matched to the correct form of diversity?

:br

:::tableoptions{col1="hide"}
| | Ecosystem diversity | Genetic diversity | Species diversity
| --- | :-: | :-: | :-: |
| A.$\hspace{1em}$ | Different habitats, communities and ecological processes | The type of alleles in a population | Genetic variation within a species |
| B.$\hspace{1em}$ | The number of species and their abundance in an area | Phenotypic variation in a community | Genetic variability within a species |
| C.$\hspace{1em}$ | Variety and abundance of different ecosystems in a geographical area| Genetic variability within a species or population | The number of species and their abundance in an area |
| D.$\hspace{1em}$ | Different habitats, communities and ecological processes | The total number and type of epigenetic markers in a population | The variety of all life on Earth|



\[Maximum mark: 16\]

1. Outline why scientists must have several approaches to conserve biodiversity.   :marks[3]

2. There are approximately 80 Javan Rhinoceros (*Rhinoceros sondaicus*) in the world. Discuss the environmental and economic implications the Indonesian government must consider before volunteering the Javan Rhinoceros to the EDGE programme.        :marks[5]

3. Explain why rapid human population growth is linked to the current biodiversity crisis.   :marks[7]



How does introducing new invasive species, such as Japanese knotweed (*Reynoutria japonica*), to ecosystems affect biodiversity?


:::center
![BI0907](question:01bd4d18-ba7d-4633-965b-1e169e05e1c7)
:span[\[Source: Adapted from Carter, W. (2019, September 11). File: reynoutria japonica in Brastad 1.jpg - Wikimedia Commons. Wikimedia commons. Retrieved July 10, 2023 from URL https<NO LINK>://commons.wikimedia.org/wiki/File: Reynoutria_japonica_in_Brastad_1.jpg. Copyright free\]]{style="font-size:14px; line-height:1"}
:::

:br

::indent
- A.$\hspace{1em}$ Increases biodiversity because there are more species in the ecosystem

- B.$\hspace{1em}$ Decreases biodiversity as the invasive species outcompetes native species for resources

- C.$\hspace{1em}$ Decreases biodiversity as new plants encourage new insects and animals to immigrate to the ecosystem

- D.$\hspace{1em}$ Increases biodiversity as the invasive species brings new pests into the ecosystem


\[Maximum mark: 7\]

Gel electrophoresis is a technique used to separate molecules such as nucleic acids. It involves loading the samples into wells in a supporting medium, often agarose gel, and applying an electric current. The diagram below shows the outcome of a gel electrophoresis run.

:::center
![BI1423](question:d39bad9c-a545-4a74-9b4b-1696d973f3d8)
:span[\[© Revision Village 2023\]]{style="font-size:14px; line-height:1"}
:::

:br

1. 
    1. Deduce in which direction DNA fragments would move through this gel.  :marks[1]

    2. State what causes the DNA to move in the direction given in (i)	:marks[1]
									  	 
2. The DNA fragments are not visible immediately after separation. Outline how gene probes can be used to identify the DNA fragments.		:marks[2]

3. DNA profiling can be used to study genetic diversity and population dynamics in various species, aiding in conservation efforts. Describe one named ex-situ conservation technique used to help preserve biodiversity.			:marks[3]

\[Maximum mark: 10\]

The image shows the changes to mixed dipterocarp forests in Southeast Asia over 100 years. Researchers have concluded that the changes are mainly due to anthropogenic factors. 

:::center
![BI0904bi](question:e6f5e4fb-0bc4-4e86-8873-13849c5e724e)
:span[\[Source: Adapted from San Jose. (2006, February 8). File: map of east asia.png - wikimedia commons. Wikimedia commons. Retrieved July 10, 2023 from URL https<NO LINK>://commons.wikimedia.org/wiki/File: Map_of_East_Asia.png. Copyright under CC BY 3.0\]]{style="font-size:14px; line-height:1"}
:::

1. Distinguish between the forest coverage in 1900 and 2000  :marks[1]

2. State the definition for ‘anthropogenic’.    :marks[1]

3. Explain two possible anthropogenic reasons for differences in forest coverage between 1900 and 2000.    :marks[2]

4. Suggest what evidence scientists would need to collect from the forests to provide evidence for a biodiversity crisis in South East Asia.    :marks[1]

5. Suggest why it might be important to increase biodiversity in the area.    :marks[1]

6. Conservationists in the area have started a reforestation project in the area, in an attempt to restore the forest to 1900 coverage levels. Discuss what effects this would have on biodiversity.    :marks[4]


\[Maximum mark: 6\]

Mountain gorillas (*Gorilla beringei beringei*)  were reclassified from "Critically Endangered" to "Endangered" by the International Union for Conservation of Nature (IUCN) in November 2018. This change in status was a significant conservation success story, reflecting the positive impact of concerted efforts by governments, conservation organisations, and local communities to protect and increase the population of this subspecies of the eastern gorilla. 
The table below shows the changes in the number of mountain gorillas from 2010 to 2018.

:::center
| Year | Number of gorillas |
| :-: | :-: |
| 2010 | 480 |
| 2016 | 604 |
| 2018 | 1004 |
:::

:br

1.  Calculate the percentage increase in the number of gorillas from 2010 to 2018.  :marks[1]
2.  Although the mountain gorilla is rarely seen in zoos, another gorilla subspecies, the western lowland gorilla (*Gorilla gorilla gorilla*) is. Explain how zoos play a critical role in the conservation of endangered species. :marks[3]


Studies have shown that the invasive plant species *Sericostachys scandens* affects forest composition and may affect the Grauer’s gorilla (*Gorilla beringei graueri*) recovery in Congo. 

3.  Outline two precautions that should be taken before considering biological control of invasive plants such as these.	:marks[2]


The table shows the number of tree species in two similarly sized forests.  Which statement about the two communities is correct?

:br
:::center
:::tableoptions{col1="hide"}
| | Tree species | Forest 1 | Forest 2
| --- | :-: | :-: | :-: |
| $\hspace{1em}$ | *Quercus alba* | 30 | 25 |
| $\hspace{1em}$ | *Acer rubrum* | 12 | 25 |
| $\hspace{1em}$ | *Fagus sylvatica*| 50 | 25 |
| $\hspace{1em}$ | *Betula occidentalis* | 8 | 25|
| $\hspace{1em}$ | **Total number of trees** | 100 | 100|

:span[\[©Revision Village 2023.\]]{style="font-size:14px; line-height:1"}
:::
:br

::indent
- A.$\hspace{1em}$ Forest 2 has the same species richness as Forest 1

- B.$\hspace{1em}$ Forest 1 has a higher species evenness than Forest 2

- C.$\hspace{1em}$ Forest 1 has a higher species richness than Forest 2

- D.$\hspace{1em}$ Forest 2 has an equal species evenness to Forest 1


\[Maximum mark: 10\]

The Eurasian beaver (*Castor fiber*) has been described as a species that promotes biodiversity. Beavers are herbivores that feed on freshwater plants and tree bark. They use their sharp front teeth to fell trees and use the logs and branches to build dams that create pools in which they can build their lodge. A beaver lodge is a construction in which they nest and raise their young, providing protection from predators.

:::center
![BI1684 fig1](question:0716c3a5-4515-4c2c-9098-2dc170bfb110)
:span[\[Source: Jerzy Strzelecki, retrieved July 2024 from https<nolink>://commons.wikimedia.org/wiki/File: Castor_fiber_07(js),_Narew_River,
_Poland.jpg, copyright under CC BY-SA 3.0\]]{style="font-size:14px; line-height:1"}
:::

:br

1.  Suggest ways in which the reintroduction of beavers can increase biodiversity. :marks[4]

The effect of introducing beavers on the species diversity of birds and bats was studied in four areas: on river banks, one without any beaver activity and one where beavers are present, and then ponds, again, one without beaver activity and one where beavers were present. The graph below shows the calculated Simpson’s reciprocal index of Diversity for each area.

:::center
![BI1684 fig2](question:536e088c-9e87-4ae5-902d-c81de6be0cb0)
:span[\[©Revision Village 2024\]]{style="font-size:14px; line-height:1"}
:::

:br

2.  State two necessary measurements to calculate Simpson’s reciprocal index of diversity.	:marks[1]

3.  Calculate the percentage increase in the species diversity of bats in the pond after the introduction of the beaver.	:marks[2]

Beavers became extinct in the UK over 400 years ago. Reintroduction programmes are now being carried out in various regions of the UK.

4.  Suggest **three** anthropogenic activities that could have led to the extinction of the beavers in the UK. :marks[3]

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

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

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

IB Biology SL - 2025 - Questionbank

A4.2 - Conservation of Biodiversity

Question 1

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Question 6

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Question 14

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