biology MCQs - 12th class Chapter 12 Mcqs

1

What do short-term fluctuations in temperature, humidity, cloud cover, and wind refer to?

A

Climate

B

Ecosystem

C

Weather

D

Biome

2

Salt-water oceans and seas are the largest ecosystems, forming about what percentage of the Earth's surface?

A

29%

B

50%

C

71%

D

99%

3

Fresh water ecosystems cover less than what percentage of the Earth's surface?

A

1%

B

5%

C

10%

D

20%

4

In the clearest water, at a depth of 600 feet or more, little light is left to power what process?

A

Respiration

B

Photosynthesis

C

Decomposition

D

Transpiration

5

Which zone in a lake ecosystem is the near-shore area where plants find abundant light and anchorage?

A

Profundal zone

B

Benthic zone

C

Limnetic zone

D

Littoral zone

6

Microscopic drifting plants like photosynthetic protista, bacteria, and algae are collectively called?

A

Zooplankton

B

Nekton

C

Phytoplankton

D

Benthos

7

Microscopic drifting animals such as protozoa and tiny crustaceans are known as?

A

Phytoplankton

B

Zooplankton

C

Producers

D

Decomposers

8

In which zone of a lake is light insufficient to support photosynthesis?

A

Littoral zone

B

Limnetic zone

C

Photic zone

D

Profundal zone

9

The process where added nutrients from sources like sewage and fertilizers cause excessive growth of phytoplankton is called?

A

Acidification

B

Desertification

C

Eutrophication

D

Succession

10

The burning of fossil fuels produces acid, which poses a serious threat to which type of ecosystem?

A

Desert ecosystem

B

Fresh-water ecosystem

C

Tundra ecosystem

D

Forest ecosystem

11

The ecosystem present on land or soil is called a terrestrial or ________ ecosystem.

A

Hydrospheric

B

Atmospheric

C

Lithospheric

D

Biospheric

12

Supporting tissues like vascular bundles (xylem-phloem) are an adaptation for plants in which environment?

A

Aquatic

B

Terrestrial

C

Marine

D

Polar

13

Which of the following is NOT listed as a main type of terrestrial ecosystem?

A

Forest ecosystem

B

Grass land ecosystem

C

Marine ecosystem

D

Desert ecosystem

14

In Pakistan, temperate deciduous forests are found in Shogran and which other valley?

A

Kaghan valley

B

Swat valley

C

Neelam valley

D

Chitral valley

15

Northern coniferous forests, characterized by harsh conditions and evergreen trees, are also called?

A

Taiga

B

Savanna

C

Prairie

D

Tundra

16

The grassland ecosystem in Pakistan is found in Gilgit, Kashmir, Waziristan, and which other location?

A

Mianwalli

B

Lower Chitral

C

Yazman

D

Neelam valley

17

In southern Punjab, the desert ecosystem found in areas like Cholistan is known as?

A

Thal

B

Thar

C

Sahel

D

Sahara

18

In Pakistan, the Tundra ecosystem is found in the mountains of Kara-Koram and where else?

A

Himalayas

B

Suleman Range

C

Hindukush

D

Kirthar Range

19

What is the average annual rainfall in temperate deciduous forests?

A

250-500 mm

B

500-750 mm

C

750-1500 mm

D

1500-2000 mm

20

Which of these animals is mentioned as very common in the temperate deciduous forests of Pakistan?

A

Snowshoe hare

B

Rhesus monkey

C

Marco polo sheep

D

Arctic fox

21

The soil of a temperate deciduous forest is described as being very fertile and what color?

A

Reddish brown

B

Black

C

Grayish brown

D

Sandy yellow

22

Coniferous forests located at high altitude are called what?

A

Boreal

B

Alpine

C

Montane

D

Taiga

23

Coniferous forests located at high latitude are called what?

A

Alpine

B

Deciduous

C

Tundra

D

Boreal

24

What adaptation helps coniferous trees reduce water loss during cold months?

A

Broad leaves

B

Deep roots

C

Waxy coating on needles

D

Shedding leaves

25

Which of these plants is found in coniferous forests like the Taiga?

A

Taxus baccata

B

Andropogon

C

Cacti

D

Pinus wallichiana

26

Grasslands found in temperate climates, like those in North America, are called?

A

Savannas

B

Prairies

C

Steppes

D

Pampas

27

Grasslands in tropical climates that have woody trees are known as?

A

Prairies

B

Taiga

C

Chaparral

D

Savanna

28

Layering, with tall, mid-high, and short grasses, is a characteristic of which ecosystem?

A

Desert

B

Tundra

C

Grassland

D

Coniferous Forest

29

The primary productivity rate in temperate grasslands is about how many grams per square meter annually?

A

100-500

B

700-1500

C

2000-3000

D

More than 4000

30

The process of converting lands into deserts, often due to over-grazing, is called?

A

Eutrophication

B

Deforestation

C

Succession

D

Desertification

31

The desert ecosystem in western Punjab (Mianwali and Bukhar) is known as?

A

Thar

B

Cholistan

C

Thal

D

Sindh

32

Rainfall in desert ecosystems is typically less than?

A

25 to 50 cm

B

50 to 75 cm

C

75 to 100 cm

D

100 to 150 cm

33

What adaptation is common in desert plants like cacti and Euphorbia to store water?

A

Large leaves

B

Deep taproots

C

Shallow root systems

D

Fleshy stems

34

Many desert animals are active at night to avoid the sun and heat. This behavior is known as being?

A

Diurnal

B

Crepuscular

C

Nocturnal

D

Sessile

35

The Sahel, which borders the southern edge of the Sahara, is a dramatic example of what process?

A

Afforestation

B

Desertification

C

Eutrophication

D

Succession

36

A vast, treeless region bordering the Arctic Ocean is known as the?

A

Taiga

B

Prairie

C

Arctic tundra

D

Boreal forest

37

In the Tundra, what type of plant is a large lichen often called reindeer moss?

A

Flower

B

Shrub

C

Moss

D

Lichen

38

The Tundra is described as the most fragile of all biomes primarily because of its?

A

High rainfall

B

Lack of animals

C

Short growing season

D

Rich soil

39

According to the text, a 50-year-old willow in the Tundra may have a trunk only what diameter?

A

1 cm

B

7 cm

C

10 cm

D

25 cm

40

What organisms serve as producers in the limnetic zone of a lake?

A

Fish

B

Snails

C

Zooplankton

D

Phytoplankton

41

The decomposers in the profundal zone feed on detritus that falls from which two zones?

A

Littoral and Benthic

B

Limnetic and Profundal

C

Littoral and Limnetic

D

Photic and Aphotic

42

Which factor, besides light, basically determines the productivity of an aquatic ecosystem?

A

Temperature

B

Pressure

C

Nutrients

D

Salinity

43

Which group includes organisms like frogs, aquatic snakes, and turtles in the littoral zone?

A

Invertebrates

B

Vertebrates

C

Decomposers

D

Producers

44

The waxy coating and small surface area of conifer needles are adaptations to prevent what?

A

Freezing

B

Water loss

C

Insect attacks

D

Sunburn

45

In grasslands, dominant animal species are typically?

A

Carnivores

B

Omnivores

C

Herbivores

D

Decomposers

46

The soil of a grassland is described as basically impermeable with excessive what?

A

Moisture

B

Humus

C

Salinity

D

Acidity

47

The 'Thar' desert ecosystem is located in which province of Pakistan?

A

Punjab

B

Khyber Pakhtunkhwa

C

Balochistan

D

Sindh

48

Which of these animals is found in the Tundra and is prey for wolves and snowy owls?

A

Lemmings

B

Rhesus monkeys

C

Bison

D

Prairie dogs

49

In the open ocean, phytoplankton are eaten by what microscopic crustaceans?

A

Krill

B

Shrimp

C

Copepods (zooplankton)

D

Crabs

50

What is the moderate temperature range for temperate deciduous forests?

A

0°C - 10°C

B

4°C - 30°C

C

15°C - 40°C

D

Below 0°C