Cuscuta	Parasite
Eichhornia	Root pocket
Monotropa	Saprophytes
Rhizophora	Pneumatophore
Utricularia	Insectivorous plant

Answer : (b)

Benthic organisms are attached or rest on the bottom sediments. These organisms are also called deep dweller in the sea. The Benthic organisms may be divided into filter feeders, clams and deposit feeders. Answer : (a)

The small isolated tribal population will have a small gene pool. Due to isolation of the population , the genes remain confined in that area itself and also no gene from outside enters in. As a reult, the population will decrease. Answer : (c)

mimicry is an evolved resemblance between an organism and another object, often an organism of another species. Often, mimicry functions to protect a species from predators, making it an anti-predator adaptation. Protection is added advantage but mimicry was evolved to conceal. Answer : (a)

Lichens represent an intimate mutualistic relationship between a fungus and photosynthesising algae or cyanobacteria. This mutually beneficial relationship is called mutual symbiosis. Answer : (a)

Xerophyte: any plant adapted to life in a dry or physiologically dry habitat by means of mechanisms to prevent water loss or to store available water. Succulents are a kind of xerophytes. Succulents (plants that store water) such as cacti and agaves have thick, fleshy stems or leaves. Answer : (c)

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. That means there will be increase in Natality and decrease in Mortality. Answer : (a)

An orchid growing as an epiphyte on a mango branch is an example of commensalism where orchid is benefited and mango tree neither benefits nor is harmed. (a) is correct. Brood parasitism 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. (b) is correct. All birds and mammals, and a very few lower vertebrate and invertebrate species are indeed capable of homeostasis. Plants, on the other hand, do not have such mechanisms to maintain internal temperatures. (c) is incorrect. Heat loss or heat gain is a function of surface area. Since small animals have a larger surface area relative to their volume, they tend to lose body heat very fast when it is cold outside; then they have to expend much energy to generate body heat through metabolism. This is the main reason why very small animals are rarely found in polar regions. (d) is correct. Answer : (c)

kangaroo rat has the ability to concentrate its urine (solid urine) so that minimal volume of water is used to remove excretory products. Answer : (b)

Succulent xerophytes are those xerophytic plants that store water and mucilage in thick, fleshy organs. Xerophytic plants are found in dry or physiologically dry habitat such as desert. Answer : (a)

xerophyte, any plant adapted to life in a dry or physiologically dry habitat (salt marsh, saline soil, or acid bog) by means of mechanisms to prevent water loss or to store available water. Halophytes are salt-tolerant plants that grow in waters with high salinity, such as in mangrove swamps, marshes, seashores and saline semi-deserts. Answer:(d)

Calotropis procera has an exceptional ability to adapt and maintain productivity in severe arid conditions. It is a C3 plant that can survive drought, salinity, extreme temperatures, high vapor pressure deficit, and high photosynthetic active radiations. Xerophytes like Calotropis have hairy covering on the leaves and stems to check transpiration. The leaves are also covered with thick cuticular wax. Answer : (b)

Genecology is a branch of ecology which studies genetic variation of species and communities compared to their population distribution in a particular environment. Answer : (c)

Answer : (c)

In primary succession on rocks these are usually lichens which are able to secrete acids to dissolve rock, helping in weathering and soil formation. These later pave way to some very small plants like bryophytes mosses, which are able to take hold in the small amount of soil. They are, with time, succeeded by higher plants like annual herbs, perennial herbs and then woody shrubs, and after several more stages, ultimately a stable climax forest community is formed. Answer : (d)

Commensalism is when two species live together but one benefits while the other is unharmed or helped. The remora removes parasites from the shark's skin and even inside the mouth, which benefits the shark. Answer : (b)

The submerged leaves are often highly dissected or divided. It minimises water resistance and hence, potential damage to the leaves since moving water (currents and waves) can be damaging to the leaves of the plant. Answer : (c)

Field capacity is the amount of soil moisture or water content held in the soil after excess water has drained away and the rate of downward movement has decreased. It consists of (I)Capillary water: It is held by cohesion and adhesion and most of it is plant available. (II) Hygroscopic water is held very tightly on the surfaces of soil particles. Answer : (d)

ecotype, sometimes called ecospecies, describes a genetically distinct geographic variety, population, or race within a species, which is genotypically adapted to specific environmental conditions. Autecology is the study of individual organisms. synecology (or community ecology) refers to the study of groups of organisms in relation to their environment. Demoecology focuses on the study of different populations in a specific area or habitat. Answer : (d)

When a species is designated as polytypic, it means that all the members of the classification can be further divided into a minimum of two subspecies. Each subspecies designation typically refers to a very specific population of organisms that can only be found in one particular habitat. Answer : (d)

The xerophytes commonly have a large proportion of sclerenchyma in their leaf structure than is observed normally in mesophytes. The sclerenchyma is either found in groups or in continuous sheets. Answer : (c)

Shortwave radiation is radiant energy with wavelengths in the visible, near-ultraviolet, and near-infrared spectra. Radio waves are a type of electromagnetic radiation with the longest wavelengths. Answer : (c)

Halophytes are salt-tolerant plants that grow in waters with high salinity, such as in mangrove swamps, marshes, seashores and saline semi-deserts. Answer:(c)

A keystone species is a species which has a disproportionately large effect on its natural environment relative to its abundance. A keystone species is an organism that helps define an entire ecosystem. Without its keystone species, the ecosystem would be dramatically different or cease to exist altogether. Examples of keystone species include starfish, sea otters, wolves and elephants. Answer:(c)

Field capacity is the amount of soil moisture or water content held in the soil after excess water has drained away and the rate of downward movement has decreased. Answer:(a)

The Arctic tern is famous for its migration. It flies from its Arctic breeding grounds to the Antarctic and back again each year, the shortest distance between these areas being 19,000 km (12,000 mi). Siberian crane are known as migratory birds. They usually travel looking for a better suitable climatic condition. The salmon run is the time of the year when salmon, which have migrated from the ocean to fresh water, swim against the stream to the upper reaches of rivers, where they spawn on gravel beds. Answer : (b)

Plants which are adapted to live under low light conditions are called sciophytes, e.g herbs. Sciophytes form the understory of a forest. Answer : (b)

mutualism	Ophrys and bee
commensalism	orchid epiphyte on mango branch
parasitism	ticks on dogs
competition	Balanus and Chthamalus
predation	sparrow and any seed

Answer : (a)

Some desert plants like Opuntia, have no leaves – they are reduced to spines– and the photosynthetic function is taken over by the flattened stems. Answer : (b)

Prey species have evolved various defenses to lessen the impact of predation. Example pufferfish. Pufferfish will “puff up” as a defense mechanism if they are threatened. A shape that is more than double its original size, round and sometimes covered in spines is much more difficult to bite and isn't very appetizing to a predator. Some species of insects and frogs are cryptically-coloured (camouflaged) to avoid being detected easily by the predator. Example: chameleons can change colour and they do this by expanding or contracting cells in their skin that contain different pigments. Another example is moth. Their wing coloration and patterns are shaped by natural selection to match the patterns of natural substrates, such as a tree bark or leaves, on which the moths rest. Answer : (c)