Organisms and Populations Test - 79

Different types of epiphytes may grow on the same tree, including orchids. The name 'epiphyte' comes from the Greek word 'epi' meaning 'upon' and 'phyton' meaning 'plant'

Commensalism is the relationship in which one is benefited while the other is neither benefited nor harmed. Sucker fish gets attached to the underside of a shark by means of its sucker. The sucker fish is taken to distant areas with better food supply and it also gets protection as it is attached to shark whereas shark does not get any benefit.

Entomophily is the pollination by insects, plants develops colourful petals and a strong scent to attract insects such as, bees, wasps and occasionally ants (Hymenoptera), beetles (Coleoptera), moths and butterflies (Lepidoptera) and flies (Diptera) for pollination. In this case flower gives nectar as a food to insects and in turn insect help them in reproduction by pollinating pollen grains. Such example is of a mutualistic relationship. Thus, the correct answer is option C.

An adaptation mechanism against the predation has developed through evolution that assists prey organisms in their constant struggle against predators. 

Tundra is the coldest of all the biomes. It is noted for its extremely low temperatures, little precipitation, poor nutrients, and short growing seasons. The tropical rain forest is a forest of tall trees in a region of year-round warmth. The temperature in a rain forest rarely gets higher than 34 C or drops below 20 C; rainfall is often more than 100 inches a year. There is usually a brief season of less rain. Grasses are the dominant vegetation in temperate grassland. Temperate grasslands have hot summers and cold winters. Summer temperatures can be over 100 degrees Fahrenheit, while winter temperatures can be as low as -40 degrees Fahrenheit. They have between 10 and 35 inches of precipitation a year, occurring in the late spring and early summer. A savannah is a grassland ecosystem characterized by the trees being sufficiently widely spaced so that the canopy does not close. The open canopy allows sufficient light to reach the ground to support an unbroken herbaceous layer consisting primarily of grasses. Savannah has distinct wet and dry seasons of relatively equal duration. Most of the region's annual rainfall is experienced during the wet season and very little precipitation falls during the dry season. Savannah climates have monthly mean temperatures above 18 C (64 F) in every month of the year.

A population survives on the resources present in an area .Which include food,water and space available in a habitat, locality or environment. All these resources are not unlimited and they can cater to a certain number of organisms also referred to as the carrying capacity, beyond which the population cannot be supported by the available resources, that is resources limit the growth of population.

Mortality is the rate of loss of individuals per unit time due to death. I.e death rate.

The clinging roots are found in the epiphytes. These roots fix the plant on the bark of the tree and also absorbs nutrients found on the tree bark. Such roots are found in orchids. Thus, the correct answer is option A.

Bacterial growth is assumed to be exponential and can be calculated by 2$$^n$$. Here, n = number of generations. 

The biggest flower of the world Rafflesia is a total root parasite found in sea shores of Java and Sumatra and Sri Lanka. Rafflesia is known as the queen of parasites, which grows on members of family Vitaceae. Orobanche and Striga are other common examples of total root parasites. Hence, the correct answer is option B.