During a total solar eclipse occurring at noon, it becomes dark enough for a few minutes for stars to become visible. The stars that are seen are those which will be seen from the same location.

• On the following night only.  

• On the night one month later.   

• On the night three months later.  

• On the night six months later.   

Which of the following statements about the concentration of CO₂ in the Earth’s atmosphere is true?

• It was the highest in the very early atmosphere of the Earth. 

• It has steadily decreased since the formation of the Earth’s atmosphere.   

• It has steadily increased since the formation of the Earth’s atmosphere.  

• Its levels today are the highest in the Earth’s history.  

The atmosphere in a sealed space craft contains      

• Pure oxygen   

• A mix of oxygen and nitrogen  

• A mix of oxygen and carbon dioxide

• Pressurized atmospheric air available normally on earth  

The Hutchinsonian concept of ecological niche is based on

• Microhabitat occupied  

• Multi-dimensional hypervolume  

• Role played in the ecosystem  

• A combination of role played and microhabitat occupied 

Aquatic primary production was measure using Light-and-Dark Bottle technique. If the initial oxygen concentration was I and the final oxygen concentration in the light bottle was L and that in the dark bottle D, the gross productivity (in terms of oxygen released) is given as

• L - I

• I - D

• I - L

• L - D

Wetlands are conserved internationally through an effort called as

• Basel convention  

• Rio convention   

• Montreal convention  

• Ramsar convention  

The rattans and canes that we use in furniture belong to

• Bamboos

• Palms

• Arvorescent lillies

• Legumes

The presence of Salmonella in tap water is indicative of contamination with

• Industrial effluents  

• Human excreta  

• Agriculture waste  

• Kitchen waste

49.

Ecological compression differs from character displacement in that it operates on a

• Shorter timescale and does not involve heritable change

• Longer timescale and does not involve heritable change.   

• Shorter timescale and involves heritable change

• Longer timescale and involves heritable change.

Autotrophs in the aquatic ecosystem, unlike their counterparts in the terrestrial ecosystem, are mostly microscopic and very low in indigestible (to the herbivores) matter. This explains the fact that compared to the terrestrial ecosystem, in the aquatic ecosystem

• Productivity/ Biomass ratios are higher and energy transfer rates to higher trophic levels are faster.  

• Productivity/ Biomass ratios are lower and energy transfer rates to higher trophic levels are slower.

• Productivity/ Biomass ratios are lower and energy transfer rates to higher trophic levels are faster.  

• Productivity/ Biomass ratios are higher and energy transfer rates to higher trophic levels are slower.