DAY – 7: Insights Self Study Guide for Prelims + Mains – 2015

Lichens represent an intimate mutualistic relationship between

Consider the following statements:

1. Permafrost is soil at or below the freezing point of water 0 °C (32 °F) for two or more years which is mainly composed of rock and gravel materials
2. Permafrost is found both in Tundra and Taiga biome regions

Which of the above statements is/are correct?

Tuna fish are mainly found in which of the following regions?

With reference to deep-sea hydrothermal vents where average temperatures exceed 100 Degree Celsius and where unique ecosystems are found, consider the following statements:

1. The vent fluid though sometimes reaches temperature of 400 degrees, it does not boil due to the presence of extremely high pressure
2. Through the process of chemosynthesis, bacteria provide energy and nutrients to vent species without the need for sunlight
3. Chemosynthetic bacteria act as producers in the hydrothermal vent ecosystem

Which of the above statements is/are correct?

If there is a sudden change in temperature, which of the following type of organisms would be best suited to tolerate the change?

Consider the following statements:

1. A freshwater fish can not live in ocean whereas a saline water fish can live in freshwater bodies
2. Salmon and European Eels can live both in fresh and saline waters
3. Fish which can live in both fresh and saline waters are known as stenohaline fishes

Which of the above statements is/are correct?

Some soils undergo aluminium (Al), hydrogen (H), and/or manganese (Mn) toxicity, as well as nutrient deficiencies of calcium (Ca) and magnesium (Mg) due to variation in soil pH. These toxicity is associated with

In an ecosystem, organisms whose internal conditions are controlled primarily by environmental conditions are called as

With reference to freshwater fishes and osmoregulation process, consider the following statements:

1. Freshwater fishes are hypertonic to their surroundings. This means their blood has a lower water concentration than the surrounding fresh water
2. Maintenance by an organism of an internal balance between water and dissolved materials regardless of environmental conditions is called as osmoregulation

Which of the above statements is/are correct?

With reference to desert plants, consider the following statements:

1. Many desert plants have a thick cuticle on their leaf surfaces and have their stomata arranged in deep pits to minimise water loss through transpiration
2. To conserve water, some plants open their stomata only at night when evaporation rates are lowest

Which of the above statements is/are INCORRECT?

With reference to altitude sickness, consider the following statements:

1. Because of high atmospheric pressure at high altitudes, the body doesn’t get sufficient oxygen – this causes nausea, fatigue and heart palpitations – all symptoms of altitude sickness
2. The body can adopt and avoid altitude sickness by decreasing both its red blood cell production and breathing rate

Which of the above statements is/are INCORRECT?

Which of the following processes decrease the density of a population in a given habitat?

1. Natality
2. Immigration
3. Mortality
4. Emigration

Choose the correct answer using the codes below:

With reference to carrying capacity of an ecosystem, consider the following statements:

1. In nature, a given habitat has enough resources to support a maximum possible number, beyond which no further growth is possible. This limit is called as nature’s carrying capacity for that species in that habitat.
2. Below carrying capacity, populations typically increase, while above, they typically decrease
3. “Ecological footprint” accounting estimates human demand compared to ecosystem’s carrying capacity

Which of the above statements is/are INCORRECT?

An association between organisms of two different species in which one is inhibited or destroyed and the other is unaffected is known as

An orchid growing as an epiphyte on a mango branch is an example of