Organisms And Population

Question 1

Father of ecology

Answer 1

Von Humboldt

Question 2

Father of ecosystems ecology

Answer 2

E. P. Odum

Question 3

Father of Indian ecology

Answer 3

Ramdeo Mishra

Question 4

Ecology is basically concerned with four levels of biological organisation

Answer 4

Organisms
Populations
Communities
Biomes

Question 5

The group of individuals resulting from even……… reproduction is also generally considered a population for the purpose of ecological studies

Answer 5

asexual

Question 6

Assertion: Population ecology is an important area because it links ecology to population genetics and evolution.

Answer 6

Reason: Although an individual organism is the one that has to cope with a changed environment, it is at the population level that natural selection operates to evolve the desired traits

Question 7

Whatever ecological processes we wish to investigate in a population, be it the outcome of competition with another species, the impact of a predator or the effect of a pesticide application, we always evaluate them in terms of any change in the……….

Answer 7

population size

Question 8

Assertion: Population size, technically called population density (designated as N), need not necessarily be measured in numbers only.

Answer 8

Reason: Although total number is generally the most appropriate measure of population density, it is in some cases either meaningless or difficult to determine.

Question 9

Parthenium hysterophorus refers to

Answer 9

Carrot grass

Question 10

The tiger census in our national parks and tiger reserves is often based on

Answer 10

Pug marks
Fecal pellets

Question 11

The density of a population in a given habitat during a given period, fluctuates due to changes in four basic processes

Answer 11

Natality
Immigration
Mortality
Emigration

Question 12

Immigration is the number of individuals of the……… species that have come into the habitat from elsewhere during the time period under consideration.

Answer 12

same

Question 13

Emigration is the number of individuals of the………. who left the habitat and gone elsewhere during the time period under consideration.

Answer 13

population

Question 14

If a new habitat is just being colonised……… may contribute more significantly to population growth than…….

Answer 14

immigration

birth rates.

Question 15

r values in exponential growth for following organisms is
Norway rat
Flour beetle
Human (old and new)

Answer 15

Norway rat= 0.015
Flour beetle =0.12
Humans (1981)=0.0205
Humans (new 2011) =0.0147

Question 16

The base of natural logarithms’e’ equal to

Answer 16

2.71828

Question 17

Some organisms breed only once in their lifetime

Answer 17

Pacific salmon fish
bamboo

Question 18

Some produce a large number of small-sized offspring

Answer 18

Oysters
Pelagic fishes
Pacific salmon
This kind of reproduction is ‘r’ type selection

Question 19

Some produce a small number of large-sized offspring

Answer 19

Birds
Mammals
This kind of reproduction is ‘k’ type selection

Question 20

The prickly pear cactus introduced into Australia in the early 1920’s caused havoc by spreading rapidly into millions of hectares of rangeland. Finally, the invasive cactus was brought under control only after a cactus-feeding predator……………….. from its natural habitat was introduced into the country.

Answer 20

Cactoblastis cactorum (moth)

Question 21

Assertion: Predators also help in maintaining species diversity in a community

Answer 21

Reason: They reduce intensity of competition among competing prey species.

Question 22

In the rocky intertidal communities of the American Pacific Coast the starfish………. is an important predator

Answer 22

Pisaster

Question 23

In a field experiment, when all the starfish (Pisaster) were removed from an enclosed intertidal area, more than……. species of…….. became extinct within a year, because of inter-specific competition.

Answer 23

10

invertebrates

Question 24

Statement 1: The Monarch butterfly is highly distasteful to its predator (bird) because of a special chemical present in its body.
Statement 2: The butterfly acquires this chemical during its caterpillar stage by feeding on a poisonous weed.

Answer 24

Both are correct

Question 25

Nearly…….. per cent of all insects are known to be phytophagous

Answer 25

25% feeding on plant sap and other parts of plants

Question 26

Calotropis produces highly poisonous …………..and that is why you never see any cattle or goats browsing on this plant

Answer 26

cardiac glycosides

Question 27

As per Darwin………. competition is a potent force in organic evolution

Answer 27

interspecific

Question 28

Some totally unrelated species could also compete for the same resource.

Answer 28

True In some shallow South American lakes, visiting flamingoes and resident fishes compete for their common food, the zooplankton in the lake.

Question 29

The competition is best defined as a process in which the fitness of one species (measured in terms of its ‘r’ the intrinsic rate of increase) is significantly lower in the presence of another species

Answer 29

True Resources need not be limiting for competition to occur; in interference competition, the feeding efficiency of one species might be reduced due to the interfering and inhibitory presence of the other species, even if resources (food and space) are abundant

Question 30

The………….in Galapagos Islands became extinct within a decade after goats were introduced on the island, apparently due to the greater browsing efficiency of the goats

Answer 30

Abingdon tortoise

Question 31

A species whose distribution is restricted to a small geographical area because of the presence of a competitively superior species, is found to expand its distributional range dramatically when the competing species is experimentally removed This phenomenon is referred to as

Answer 31

Competitive release

Question 32

Example of competitive release

Answer 32

On the rocky sea coasts of Scotland, the larger and competitively superior barnacle Balanus dominates the intertidal area, and excludes the smaller barnacle Chathamalus from that zone.

Question 33

In general……… & ………….. appear to be more adversely affected by competition than carnivores.

Answer 33

herbivores and plants

Question 34

………………. of …………. states that two closely related species competing for the same resources cannot co-exist indefinitely and the competitively inferior one will be eliminated eventually

Answer 34

‘Competitive exclusion principle’ Gause

Question 35

Statement 1: The species facing competition might evolve mechanisms that promote co-existence rather than exclusion. Statement 2; One such mechanism is ‘resource partitioning’

Answer 35

Both are correct For instance could avoid competition by choosing different times for feeding or different foraging patterns

Question 36

………… showed that……. closely related species of warblers living on the same tree were able to avoid competition and co-exist due to behavioural differences in their foraging activities.

Answer 36

MacArthur five

Question 37

In order to be successful with the host species parasites evolved special adaptations such as (4)

Answer 37

Loss of unnecessary sense organs Presence of adhesive organs or suckers to cling on to the host Loss of digestive system High reproductive capacity.

Question 38

The human liver fluke (a trematode parasite) depends on two intermediate hosts (2) to complete its life cycle.

Answer 38

a snail and a fish Various species of freshwater fish, particularly those in the Cyprinidae family Freshwater snails, particularly those from the family Lymnaeidae

Question 39

Majority of the parasites harm the host they may reduce……./……/……of the host and reduce its population density.

Answer 39

the survival growth reproduction

Question 40

Ectoparasites examples

Answer 40

Ticks on dogs Live on humans Copepods on marine fishes

Question 41

…………… a parasitic plant that is commonly found growing on hedge plants, has lost its chlorophyll and leaves in the course of evolution.

Answer 41

Cuscuta

Question 42

Assertion: The female mosquito is not considered a parasite

Answer 42

Reason: They just feed on blood for reproduction, they don't live on or in the host, unlike true parasites

Question 43

Statement 1: The life cycles of endoparasites are more complex because of their extreme specialisation. Statement 2: Their morphological and anatomical features are also complex emphasising their reproductive potential.

Answer 43

Statement 1 is correct and 2 is incorrect Their morphological and anatomical features are greatly simplified while emphasising their reproductive potential.

Question 44

………….. in birds is a fascinating example of parasitism in which the parasitic bird lays its eggs in the nest of its host and lets the host incubate them

Answer 44

Brood parasitism

Question 45

Brood parasitism is seen in ………… & ………….. during breeding season ie………….. season

Answer 45

Cuckoo (Koel) and crow The Asian Koel, a cuckoo bird, is a brood parasite that lays its eggs in the nests of House Crows, which then raise the Koel chicks, while the Koel does not build its own nest

Question 46

……………… is the interaction in which one species benefits and the other is neither harmed nor benefited.

Answer 46

Commensalism

Question 47

Examples of commensalism (4)

Answer 47

An orchid growing as an epiphyte on a mango branch Barnacles growing on the back of a whale The cattle egret and grazing cattle Sea anemone clown fish

Question 48

Explain example of egret and cows

Answer 48

The egrets always forage close to where the cattle are grazing because the cattle, as they move, stir up and flush out insects from the vegetation that otherwise might be difficult for the egrets to find and catch

Question 49

Explain commensalism in sea anemone (Heteractis magnifica) and clown fish (Amphirion ocellaris)

Answer 49

The clown fish that lives among anemones and gets protection from predators which stay away from the stinging tentacles. The anemone does not appear to derive any benefit by hosting the clown fish.

Question 50

Lichens represent an intimate mutualistic relationship between a fungus and photosynthesising algae only

Answer 50

False Algae or Cyanobacteria

Question 51

Statement 1: In many species of fig trees, there is a tight one-to-one relationship with the pollinator species of wasp. Statement 2: It means that a given fig species can be pollinated only by its ‘partner’ wasp species and no other species.

Answer 51

Both are correct

Question 52

The female wasp uses the fruit as an ……………… site and developing seeds within the fruit for……….

Answer 52

oviposition (egg-laying) site nourishing its larvae.

Question 53

The Mediterranean orchid……… employs ‘sexual deceit’ to get pollination done by a species of bee……..

Answer 53

Ophrys speculam Colpa

Question 54

In Ophrys a petal of flower bears an uncanny resemblance to the female of the bee in (3) aspects

Answer 54

size colour markings

Question 55

Statement 1: The male bee is attracted to what it perceives as a female, ‘pseudocopulates’ with the flower, and during that process is dusted with pollen from the flower. Statement 2: When this same bee ‘pseudocopulates’ with another flower, it transfers pollen to it and thus, pollinates the flower.

Answer 55

Both are correct

Question 56

Co evolution operates in the example of Colpa and Ophrys

Answer 56

True If the female bee’s colour patterns change even slightly for any reason during evolution, pollination success will be reduced unless the orchid flower co-evolves to maintain the resemblance of its petal to the female bee.

Question 57

Aposematic colouration means

Answer 57

Warning colouration where organisms display bright colors to signal toxicity or unpalatability to predators. Correct, because the caterpillar's bright colors warn predators of its toxic nature.

Question 58

Batesian Mimicry refers to

Answer 58

This occurs when a harmless species mimics a toxic species to avoid predation.

Question 59

Müllerian Mimicry refers to

Answer 59

This happens when two or more toxic species resemble each other to reinforce the warning signal.

Question 60

Ecology at the organismic level is essentially………. ecology which tries to understand how different organisms are adapted to their environments in terms of……../…….

Answer 60

physiological survival and reproduction.

Question 61

On planet Earth, life exists not just in a few favourable habitats but even in extreme and harsh habitats –

Answer 61

scorching Rajasthan desert rain-soaked Meghalaya forests deep ocean trenches torrential streams permafrost (snow laden) polar regions high mountain tops thermal springs stinking compost pits

Question 62

The key elements that lead to so much variation in the physical and chemical conditions of different habitats are

Answer 62

Temperature Water Light Soil

Question 63

Along with the abiotic or physico-chemical components The habitat also includes biotic components also –

Answer 63

Pathogens parasites Predators Competitors

Question 64

Each organism has an invariably defined range of conditions that it can tolerate, diversity in the resources it utilises and a distinct functional role in the ecological system, all these together comprise its……..

Answer 64

niche

Question 65

………… is the most important ecologically relevant environmental factor

Answer 65

Temperature

Question 66

It ranges from……. levels in polar areas and high altitudes to…….. in tropical deserts in summer.

Answer 66

subzero >50*C

Question 67

There are, however, unique habitats such as thermal springs and deep-sea hydrothermal vents where average temperatures exceed……

Answer 67

100*C

Question 68

It is general knowledge that mango trees do not and cannot grow in………. countries like Canada and Germany

Answer 68

temperate

Question 69

Snow leopards are not found in…….. forests and tuna fish are rarely caught beyond……….latitudes in the ocean.

Answer 69

Kerala Tropical

Question 70

A few organisms can tolerate and thrive in a wide range of temperatures they are called……..

Answer 70

eurythermal

Question 71

A vast majority of them are restricted to a narrow range of temperatures such organisms are called

Answer 71

stenothermal

Question 72

The life on earth originated in…….. and is unsustainable without it

Answer 72

water

Question 73

For aquatic organisms the quality of water becomes important. This is in terms of

Answer 73

chemical composition pH

Question 74

The salt concentration (measured as salinity in parts per thousand), is less than……. in inland waters and……… in the sea and…….. in some hypersaline lagoons

Answer 74

5 30-35 > 100

Question 75

Some organisms are tolerant of a wide range of salinities………… but others are restricted to a narrow range……..

Answer 75

euryhaline stenohaline

Question 76

Many freshwater animals cannot live for long in sea water and vice versa because of the……..

Answer 76

osmotic problems

Question 77

Assertion: Many species of small plants (herbs and shrubs) growing in forests are adapted to photosynthesise optimally under very low light conditions. Reason : They are constantly overshadowed by tall, canopied trees

Answer 77

Both are correct and correct explanation

Question 78

For many animals too, light is important in that they use the diurnal and seasonal variations in light intensity and duration (photoperiod) as cues for timing their foraging, reproductive and migratory activities

Answer 78

True

Question 79

Assertion: The spectral quality of solar radiation is also important for life. Reason: The UV component of the spectrum is harmful to many organisms while not all the colour components of the visible spectrum are available for marine plants living at different depths of the ocean.

Answer 79

Both are correct and correct explanation

Question 80

Various characteristics of the soil such as soil composition, grain size and aggregation determine the …………. & ………….. of the soils

Answer 80

percolation and water holding capacity

Question 81

Under normal conditions………/…….. are the most important factors influencing population density

Answer 81

births and deaths

Question 82

Ideally, when resources in the habitat are unlimited, each species has the ability to realise fully its innate potential to grow in number. Then the population grows in an exponential or geometric fashion

Answer 82

True

Question 83

Any species growing exponentially under unlimited resource conditions can reach enormous population densities in a short time

Answer 83

True

Question 84

A population growing in a habitat with limited resources show initially a lag phase, followed by phases of acceleration and deceleration and finally an asymptote, when the population density reaches the carrying capacity This type of population growth is called

Answer 84

Verhulst-Pearl Logistic Growth

Question 85

Parasitism has evolved in so many taxonomic groups from plants to higher…….

Answer 85

vertebrates

Question 86

The life cycles of parasites are often…….involving one or two intermediate hosts or vectors to facilitate parasitisation of its primary host.

Answer 86

complex