Topic 2: Biodiversity and Extinction

Question 1

____ deescribes the variety of species in an ecosystem and the essential interdependence of all life forms.

Answer 1

biodiversity

Question 2

The number of species in an area described as ____.

Answer 2

species richness

Question 3

Species richness tends to be higher near the ___ - ___ have the highest biodiversity.

Answer 3

equator; tropical rainforests

Question 4

Three types of biodiversity: (3)

Answer 4

1. Species Diversity
2. Ecosystem Diversity
3. Genes Diversity

Question 5

____ defined as the number of different species present in a place and relative abundance of each of those species.

Answer 5

species diversity

Question 6

____ defined as the variety of different habitats, communities and ecological processes.

Answer 6

ecosystem diversity

Question 7

____ describes the total number of different alleles found within a species.

Answer 7

genes diversity

Question 8

Importance of Biodiversity: (4)

Answer 8

1. It protects against the climate.
2. It ensures food security.
3. It fights disease.
4. It supports communities.

Question 9

____ is the complete disappearance of a species from Earth. The natural process of organisms dying off and naturally occurs at a slow rate (usually after a catastrophic event).

Answer 9

extinction

Question 10

How does extinction happen?

Answer 10

If an environmental change occurs faster than animals and plants can adapt to it.

Question 11

A ____ is a short period of geological time in which a high percentage of biodiversity, or distinct species—bacteria, fungi, plants, mammals, birds, reptiles, amphibians, fish, invertebrates—dies out.

Answer 11

mass extinction

Question 12

Five of some mass extinctions: (5)

Answer 12

1. Cretaceous-Paleogene Period (66 MYA)
2. Triassic-Jurassic Period (200 MYA)
3. Permian-Triassic Period (250 MYA)
4. Devonian Period (374 MYA)
5. Ordovician-Silurian Period (443 MYA)

Question 13

Factors that can contribute to mass extinction: (5)

Answer 13

1. changes in sea levels
2. continental movement
3. geologic events (e.g., volcanic eruptions)
4. global warming and cooling
5. meteor impact

Question 14

An ____ refers to the rate at which species are disappearing or becoming extinct from the Earth. It is typically measured as the number of species that go extinct over a specific period of time, often expressed as extinctions per million species per year (E/MSY) or as a percentage of the total number of species on Earth.

Answer 14

extinction rate

Question 15

Three classifications of species at risk: (3)

Answer 15

1. extirpated
2. endangered
3. threatened

Question 16

___ refers to when the species is extinct from an ecosystem, but exists elsewhere.

Answer 16

extirpated

Question 17

___ refers to when a species is facing extinction/ extirpation.

Answer 17

endangered

Question 18

____ refers to when a species is at risk of being endangered if factors are not changed.

Answer 18

threatened

Question 19

Over ___% of the species that have ever existed are extinct (Begum, 2021).

Answer 19

98

Question 20

Today, ___ (___%) endemic species are threatened with extinction in the Philippine Archipelago (Birdlife International, 2021).

Answer 20

93 (36%)

Question 21

Nine of the best-known endangered species in the Philippines: (9)

Answer 21

1. Philippine Eagle
2. Tamaraw
3. Philippine Crocodile
4. Walden’s Hornbill
5. Net Coral
6. Visayan Warty Pig
7. Tarsier
8. Philippine Forest Turle
9. Negros Bleeding-Heart

Question 22

Philippines accounts for almost two-thirds of the earth’s biodiversity and approximately ____ plant and animal species can be found in the archipelago, half of which are endemic. In addition, the country hosts ____ Key Biodiversity Areas (KBAs).

Answer 22

53,000; 228

Question 23

The Philippines has lost ___% of its original forest cover since the 1900s, while an estimated ____
hectares of forest cover are lost annually due to logging, slash-and-burn cultivation, rural population
expansion, and land conversion.

Answer 23

93%; 47,000

Question 24

The severity of biodiversity loss is further emphasized by the alarming number of threatened species: The Department of Environment and
Natural Resources (DENR) has identified ____ threatened plant and animal species, while ____ plant species were further classified as “critically endangered, endangered, and threatened” in 2013. These alarming trends of loss shed light on the urgent need for concentrated efforts to address threats to biodiversity.

Answer 24

700; 984

Question 25

Two types of causes of extinction: (2)

Answer 25

1. Natural Causes
2. Anthropogenic Causes

Question 26

Natural causes of extinction: (4)

Answer 26

1. Natural Disasters
2. Competition
3. Disease
4. Climate Change

Question 27

Anthropogenic causes of extinction: (8)

Answer 27

1. Pollution
2. Overexploitation
3. Habitat Destruction and Fragmentation
4. Invasive Species
5. Habitat Degradation
6. Illegal Wildlife Trade
7. Over-harvesting of Resources
8. Agricultural Practices

Question 28

Examples conservation practices to mitigate extinction: (4)

Answer 28

1. Legislation and Regulation
2. Education and Awareness
3. Monitoring and Research
4. Breeding and Reintroduced Programs
5. Legally Binding Agreements