When a freshwater protozoan possessing a contractile vacuole, is placed in a glass containing marine water, the vacuole will:

1. Disappear

2. Increase in size

3. Decrease in size

4. Increase in number 

One of the parents of a cross has a mutation in its mitochondria. In that cross, that parent is taken as a male. During the segregation of $F_2$ progenies that mutation is found in:

1. None of the progenies

2. All the progenies

3. 50% of the progenies

4. 1/3 of the progenies 

An ecosystem that can be easily damaged but can recover after some time if the damaging effect stops will have: 

1. High stability and low resilience
2. Low stability and low resilience
3. High stability and high resilience
4. Low stability and high resilience 

In which of the following pairs is the specific characteristic of a soil not correctly matched:

1. Terra rossa – Most suitable for roses

2. Chernozems – the richest soil in the world

3. Black soil – Rich in calcium carbonate

4. Laterite – Contains an aluminium compound

Recently Govt. of India has allowed the mixing of alcohol in petrol. What is the amount of alcohol permitted for mixing in petrol:

1. 10–15%

2. 10%

3. 5%

4. 2.5%

In a longitudinal section of a root, starting from the tip upward, the four zones occur in the following order:

The presence of gills in the tadpole of a frog indicates that:

In oogamy, fertilization involves:

Which one of the following is a living fossil:

1. Moss
2. Saccharomyces
3. Spirogyra
4. Cycas

In which one of the following habitats does the diurnal temperature of the soil surface vary most?

1. Forest

2. Desert

3. Grassland

4. Shrubland