# BIO 102 | Study Mode

Question 191
A
< 30 ppm
B
< 3.0 ppm
C
< 10 ppm
D
< 100 ppm
##### Explanation
Strength of sewage of degree of water pollution is measured in terms of BOD (Biological oxygen demand) value. BOD may be defined as, number of milligrams of 02 required for decomposition of one litre of waste or water by decomposing micro-organisms (bacteria). According to central pollution control board, limit of BOD prescribed is 30 ppm (mg/d) for 3 days at 27 C.

Question 192
A
SE < PE < S < DE
B
PE < S < SE < DE
C
S < DE < PE < SE
D
SE < S < PE < DE.
##### Explanation
The BOD of the given pollutants in ascending order is PE < S < SE < DE

Question 193
A
NOx
B
SPM
C
CO
D
SO2.
##### Explanation
SPM is suspended particulate matter which is less than 10 p.m remaining in air for more than one day to several weeks. It includes aerosol, dust, mist, smoke, soot etc.

Question 194
A
population
B
landscape
C
ecosystem
D
biotic community.
##### Explanation
Population has several characteristics or attributes which are a function of the whole group and not of individual. Age distribution is one of them that is the number or the percentage of individuals in a population in different age groups. This is represented geometrically in the form of age pyramid.

Question 195
A
fresh weight
B
dry weight
C
number of individuals
D
rate of energy flow
##### Explanation
Ecological pyramids represents the tropic structure and tropic function of an ecosystem. In an ecological pyramid, the first tropic level forms the base and successive tropic levels the tiers which make up the apex. Ecological pyramids may be of three general types pyramid of number, pyramid of biomass and pyramid of energy.

Pyramid of biomass i.e. the living weight of the organisms of the food chain present at any time in an ecosystem forms the pyramids of biomass. The pyramid of biomass indicates the decrease or the gradual reduction in biomass at each trophic level from base to apex. Fresh weight is not used in ecological pyramids.

Question 196
A
mutualism between two species
B
active cooperation between two species
C
two different parasites on the same host
D
sharing of one or more resources between the two species (2006)
##### Explanation
Niche/ecological niche is specific part of habitat occupied by individuals of a species which is circumsribed by its range of tolerance, range of movement, microclimate, type of food and its availability, shelter, type of predator, and timing of activity. A habitat has several ecological niches and supports a number of species.

An ecological niche is used by a single species. Two or more species cannot use the same niche despite having a mutualistic association. Organisms or populations in competition have a niche overlap of a limited resource for which they compete.

Both owl and cat feed on shrews and mice. They occupy the same niche because of being ecological equivalents though their habitats are different.

Question 197
A
a bi-modal distribution
B
a T-shaped curve
C
a skewed curve
D
a normal distribution.
##### Explanation
It the mean and the median pertaining to a certain character of a population are of the same value a normal distribution is most likely to occur.

Question 198
A
intra specific competition
B
inter specific competition
C
predation on one another
D
mutualism.
##### Explanation
Competition is rivalry for obtaining the same resource. Competition is of two types, intraspecific and interspecific. Intraspecific competition is the competition amongst members of the same species for a common resource.

It may be for food, space, and mate. So if the density of elephant population in an area increases, it will lead to intraspecific competition. This will lead to the establishment of territories in elephants which will result in pushing out of the extra number securing shelter, mate and food for the rest.

Question 199
A
tropical deciduous forest
B
temperate evergreen forest
C
temperate deciduous forest
D
tropical rain forest.
##### Explanation
Net primary productivity is the total organic matter stored by producers per unit area per unit time. Gross primary productivity is the total organic matter synthesized by producers in the process of photosynthesis per unit area per unit time. So

Net primary productivity = Gross productivity Respiration and other losses.

Tropical rain forests occur over equatorial/subequatorial regions with abundant warmth and rainfall. Diversity and productivity are maximum as compared to other regions.

Question 200
A
blood-worms
B
stone flies
C
sewage fungus
D
sludge-worms.
##### Explanation
Some plants and animals act as the measure of existing environmental conditions because of their response to these conditions. The organisms are called bioindicators. From the given options, stone flies do not act as bioindicator of water pollution.

Try this quiz in in E-test/CBT Mode
switch to

Question Map
Quiz link
Share BIO 102 with your audience
​​​Help keep QUIZZERWEB running!
A donation makes a contribution towards the costs, the time and effort that's going on in building and improving this platform.