BIOLOGY 1 Marks Question

Commensalism: Commensalism is an interaction between two species in which one species gets benefited while the other remains unaffected. An orchid growing on the branches of a mango tree and barnacles attached to the body of whales are examples of commensalisms.

Corals

Camouflage: It is a strategy adapted by prey species to escape their predators. Organisms are cryptically coloured so that they can easily mingle in their surroundings and escape their predators. Many species of frogs and insects camouflage in their surroundings and escape their predators.

Man, (Homo sapiens)

Mutualism: It is an interaction between two species in which both species involved are benefited. For example, lichens show a mutual symbiotic relationship between fungi and blue green algae, where both are equally benefited from each other.

Interspecific competition: It is an interaction between individuals of different species where both species get negatively affected. For example, the competition between flamingos and resident fishes in South American lakes for common food resources i.e., zooplankton.

Black bear

Symbiosis/Mycorrhizae/Mutualism.

Conduits of energy transfer to the next trophic level/prey population is kept under control/helps in biological control/maintains species diversity.

When volume is considered surface area is large, loss of heat is more in cooler regions/difficult to generate more heat.

Small animals have larger surface area relative to their volume loose heat very fast, due to small size, expend much energy to generate body heat through metabolism.

(In nature) a given habitat has enough (limited) resources to support a maximum possible number, no further growth in population is possible

Absorbs phosphorus, provide resistance to root borne pathogens, enhanced to tolerate salinity/drought.

Snail and Fish.

(Many species of) Zooplankton, unfavourable condition.

Feed on plant parts/plant sap.

0.1, individuals per fruitfly per week.

Eicchornia crassipes/water hyacinth.Stagnant water/Eutrophic/nutrient enriched water bodies/polluted with nutrients.

Transport/ to reach new food sources, protocooperation.

In seed-bearing plants, the seeds and other vegetative reproductive structures serve to tide over the unfavourable conditions, they germinate to form new plants under favourable conditions.

Green algae or plants are not found beyond a certain depth, as light (not all colour components of visible spectrum) is not available.

Homeostasis enhances the overall fitness of organisms because all biochemical reactions and physiological functions proceed with maximal efficiency.

Soil composition, grain size and aggregation.

Eurythermal.

Amensalism and commensalism.

The problem is severe in case of plants as they cannot run away from the predators.

If the unfavourable (stressful) conditions are for a short duration and if the animals are not able to migrate, they hibernate during extreme winter to avoid the stress by escaping in time.

Parasitism has evolved because it ensures free lodging and food to the organism.

Predation.

Sucker fish and shark is commensalism.

Competitive release is a phenomenon in which a species whose distribution is restricted to a small geographical area because of the presence of a competitively superior species, is found to expand drastically when the competing species is removed.

Flowering in plants and migration in animals.

1. Rotation of earth around the Sun.
2. Tilt of the earth on its axis.

Bamboo; Pacific Salmon Fish.

Dragonfly.

Mammals from colder climates generally have shorter ears and limbs to minimize heat loss. This is called Allen's rule.

The human liver fluke requires two intermediate hosts, i.e. freshwater snail and fish to complete its life cycle and facilitates parasitisation of its primary host.

In all these, the interacting species live closely together and one of the species is benefitted.

Competitive release is a phenomenon in which a species whose distribution is restricted to a small geographical area because of the presence of a competitively superior species, is found to expand drastically when the competing species is removed.

The mammals are most successful animals on earth because they can maintain a constant body temperature with high range of tolerance whether in Antarctica or in Sahara desert.

Immigration and natality influence population density.

It is amensalism.

Keoladeo National Park.

The birth rate of frog population is 40/200, i.e. 200 per thousand or 20 percent or 0.2 per individual.

Population density refers to the total number of individuals of a species present per unit area or volume at a given time.

Commensalism.

Mammals have a thick layer of fat, which is called blubber below their skin that acts as an insulator and reduces loss of body heat (e.g. seals).

Green algae or plants are not found beyond a certain depth, as light (not all colour components of visible spectrum) can reach only till a certain depth in seas and oceans.

Amensalism.

Allen's rule refers to the reduction of heat loss in animals by having shorter ears and limbs.

Due to behavioural differences in their foraging activities.

Due to behavioural differences in their foraging activities.

Euryhaline.

1. The removal or downward movement of soluble chemicals from soil by water is called leaching.
2. The response of organism to number and duration of day lengths is called as photoperiodism.

1. Organisms.
2. Populations.
3. Communities.
4. Biomes.

Commensalism.

Osmoconformers.

The J-shaped growth curve indicates the minimum or absence of environmental resistance.

Parasitism.

1. Tropical rain forest.
2. Desert.

1. Biotic community is defined as a group of different populations living at one place and interacting with one another in several ways.
2. Biome is a major terrestrial biotic community characterised by distinctive live form, e.g., temperate deciduous forest, grassland etc.

The two primary requirements of a parasite from the host are:

1. Shelter.
2. Nutrition.

1. Variation in the intensity and duration of temperature.
2. Variation in precipitation.

Crassulacean Acid Metabolism.

The organism which can tolerate and thrive in a wide range of temperatures is called eurythermal.

Migration.

Problem of predation is severe for plants because they cannot move away from their predators.

Parasitism (Ectoparasite).

Life history variations have evolved in organisms to maximise their reproductive fitness or Darwinian fitness in their natural habitats.

Birds are more likely able to cope with global warming as they can tolerate a wide range of temperatures (eurythermals).

Migration refers to the movement of animals from the stressful habitat to a more hospitable area and return to the original place once the stressful period is over.

Species that can tolerate narrow range of temperature are called Stenothermic.

The place where an organism lives and reproduces is called its habitat.

The herbs and shrubs growing in the forests are adapted to photosynthesise optimally under very low lightconditions.

Ecology at the organismic level is essentially physiological ecology, which tries to understand how different organisms are adapted to their environments in terms of not only survival but also reproduction.

When we go up the altitude, beyond a particular height no tree are found and the vegetation comprise only of shrubs and herbs. The altitude beyond which no tree is seen is known as tree line.

Thermoregulation is an energy-expensive phenomenon; considering the cost and benefit, many animals have not evolved thermoregulation.

Interspecific interactions are:
Predation, Parasitism, commensalism, Mutualism and competition.

Ecological niche of an organism refers to the ranges of tolerance, the resources it utilises and its functional role in an ecosystem.

Cause of annual variations in the distinct seasons:

1. Tilt of the earth on its axis.
2. Rotation of earth around the sun.

1. Lichens formed jointly by an alga and fungus.
2. Termites harbouring cellulose digesting protozoans.

By introducing a cactus-feeding moth.

Osmoconformers are those organisms which regulate the osmolarity of their body fluids according to their surrounding medium.

Vivipary means germination of seeds, while still attached to the tree. It is exhibited in halophytes.

Sigmoid growth curve of a population indicates following characteristics:

1. Initially the growth is slow.
2. The growth becomes rapid and the curve becomes steady due to environmental resistance.

Coevolution in parasitism refers to the process in which the parasite evolves mechanisms to counteract and neutralise the mechanisms evolved by the host to reject or resist the parasite.

Species that tolerate narrow range of salinity are called stenohaline species.

Birds will be able to cope with global warming; they are eurythermals and can tolerate a wide range of temperatures.

Capsaicin produced by bell pepper.

Pacific salmon fish and bamboo.

Acceleration Increasing rate of populations. Deceleration Decreasing rate of populations.

1. Leaves are reduced to spines to check transpiration.
2. Spines keep away the browsing animals.

Predators are prudent in nature because if a predator is too efficient and over-exploits its prey, then the prey might become extinct and following it, the predator will also become extinct.

Tiger population in natural parks is based on pugmarks.

According to Allen’s rule, mammals in colder climate have shorter ears and shorter limbs to minimise heat loss.

Amensalism.

Honey bee.

1. In winter.
2. To tide over extreme cold conditions.

Calotropis produces highly poisonous cardiac glycosides that can make the herbivore sick and hence, they are not grazed by goats and cattle.

The interaction is commensalism.

Amino acid normally accumulated by xerophytes is proline.

Ramdeo Misra.

Competition.

Parasitism.

Human intestine.

Bears escape from stressful time in winter by going into hibernation, also known as winter sleep.

1. 'r' is the intrinsic rate of natural increase
2. Increase in 'r' increases the population size while decrease in 'r' decreases the population size.

Natality is defined as the number of births that are added to the initial density in a population during a given period of time.

Mutualism.

1. Timing their foraging.
2. Migratory activities.
3. Reproduction.

1. Plants depend on animals (mainly insects) for pollination.
2. They also depend on animals for dispersal of seeds and/ or fruits.
3. They depend on the soil microbes, which can carry out decomposition of organic matter and return the inorganic nutrients to the soil for absorption by plants.

It is due to the low atmospheric pressure of high altitudes that the body is unable to get enough oxygen.

The organisms which are restricted to a narrow range of temperature are called stenothermals.

The mode of interaction between two species where one is harmed and the other is unaffected is called amensalism.

1. Presence of adhesive organs or suckers to cling on the host.
2. Loss of digestive system and high reproductive capacity.

Fishes in Antarctica region accumulate anti-freeze proteins and glycerol, which lower the freezing point of body fluids, making them capable to survive in adverse conditions.

Species that can tolerate wide range of salinity are called Euryhaline.

Lion.

When the snails are not able to migrate from the stressful conditions in the habitat, they undergo aestivation during hot summers to avoid stress by escaping in time.

The interaction between two species is called interspecific interaction.

Aerenchyma gives buoyancy to the aquatic plants due to presence of air chambers.

Snails and fish go into aestivation in summer.

Phytophagous.

The sediment characteristics determine the benthic animals in an aquatic ecosystem.

In order to maximise reproductive fitness of individual, life history of variation has evolved.

Mycorrhiza is a symbiotic association between a fungus and the roots of higher plants.

Flowers of some plants open or close in response to light and darkness, the phenomenon is called photonasty.

Variety of phenotypes observed in a population.

Tapeworm.

By introducing its predator, i.e. cactus-feeding moth in the country.

Resource partitioning, it was shown by Mac Arthur.

Snail and fish.

Carrying capacity is defined as the maximum number of individuals of a population that can be sustained by a given habitat or ecosystem.

Mutualism.

Herbivores.

Ecological niche of an organism represents the range of conditions it can tolerate, the resources it utilizes and its functional role in the ecosystem.

Their ability to maintain a constant body temperature irrespective of the environmental temperature.

Partial regulaters are those species which have the ability to regulate, but only over a limited range of environmental conditions, beyond which they simply conform.

Polar bears tolerates narrow range of temperature so these are called stenothermal animals, while cows and dogs can tolerate and survive variety of temperature and are called eurythermal animals.

Sciophytes.

Species that tolerate wide range of temperature are called Eurythermic species.

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

Bears go into hibernation in winter.

Euryhaline.

Due to greater browsing efficiency of goats that were introduced in Galapagos Island.

Stenothermal organisms.

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

Chameleon.

The interaction is mutualism.

1. Parasitism.
2. Mutualism.
3. Commensalism.
4. Brood parasitism.

Exponential.

Mortality refers to the number of deaths in the population during a given period.

Tiger census is carried out by counting the pug marks or faecal pellets.

Eurythermal organisms, e.g. birds show wide range of distribution because they can thrive in wide range of temperature.

Mutualism.

To acclimatise in high altitude, the people have more haemoglobin/high RBC count to compensate for the low oxygen availability.

Eurythermal species: They can tolerate and thrive in a wide range of temperatures.

Adaptation is defined as any morphological, physiological or behavioural attribute of an organism that enables it to survive and reproduce in its habitat.

Predation and parasitism.

1. Predation helps to check the ecological balance in nature.
2. Predation helps in maintaining species diversity as in abs.ce of predator there will be more interspecific competition.

Many zooplanktons in lakes and ponds enter diapause. They enter into diapause due to some adverse environmental conditions such as drought, extreme temperature, reduced food availability, which in turn, delays the overall development.

Siberian crane.

Ectotherms are those animals whose body temperature changes and matches with that of the environment in which they are living. They are also called cold-blooded animals.

Algae (blue-green algae) and fungi together form lichen.

Population ecology is an important area of ecology, because it links ecology with population genetics and evolution; natural selection operates at the level of population.

Parasitic plants are Cuscuta and Viscum and parasitic animals are mites and lice.

The mammals of colder seas have a thick layer of fat (called blubber) beneath their skin, which acts as an insulator and reduces loss of body heat.

1. Brood parasitism.
2. Commensalism.
3. Ectoparasitism.
4. Commensalism.