Which domestic sewage mixes with river water
small animals like rats will die after drinking river water
the increased microbial activity releases micronutrients such as iron
the increased microbial activity uses up dissolved oxygen
the increased microbial activity uses up dissolved oxygen
C.
the increased microbial activity uses up dissolved oxygen
Domestic sewage consists a lot of degradable organic matter. When this sewage is released into river water, it will result in an increase of Biochemical oxygen demand (BOD) and decrease the amount of dissolved oxygen due to the decomposing activity of microbes.
Study the four statements (1-4) given below and select the two correct one out of them.
1. A lion eating a deer and a sparrow feeding on grain are ecologically similar in being consumers
2.Predator starfish pisaster helps in maintaining species diversity of some invertebrates
3.Predators ultimately lead to the extinction of prey species
4.Production of chemicals such as nicotine, strychnine by the plants are metabolic disorders
The two correct statements are
(2) and (3)
(3) and (4)
(1) and (4)
(1) and (4)
The breakdown of detritus into smaller particles by earthworm is a process called
humification
fragmentation
mineralisation
mineralisation
The biomass available for consumption by the herbivores the decomposers is called
net primary productivity
secondary productivity
standing crop
standing crop
An imporved variety of trasgenic basmati rice
does not require chemical fertilisers and growth hormones
gives high yield nd is rich in vitamin-A
is completely resistant to all insect pests and diseases of paddy
is completely resistant to all insect pests and diseases of paddy
