Organisms and Population

Organisms and Population

1. Which one of the following is most appropriately defined?

a) Host is an organism which provides food to another organism.

b) Amensalism is a relationship in which one species is benefited whereas the other is unaffected.

c) Predator is an organism that catches and kills other organism for food.

d) Parasite is an organism which always lives inside the body of other organism and may kill it.

 

2. Study the four statements (1 to 4) given below and select the two correct ones out of them

a) A lion eating a deer and a sparrow feeding on grain are ecologically similar in being consumers.

b) Predator star fish Pisaster helps in maintaining species diversity of some invertebrates.

c) Predators ultimately lead to the extinction of prey species.

d) Production of chemicals such as nicotine, strychnine by the plants is metabolic disorders.

The two correct statements are

a) (B) and (C)

b) (C) and (D)

c) (A) and (D)

d) (A) and (B)

 

3. Which two of the following changes ( 1 to 4) usually tend to occur in the plain dwellers when they move to high altitudes(3500 m or more)?

A) Increase in red blood cell size

B) Increase in red blood cell production

C) Increased breathing rate

D) Increase in thrombocyte count

a) (B) and (C)

b) (C) and (D)

c) (A) and (D)

d) (A) and (B)

4. Consider the following four conditions (A-D) and select the correct pair of them as adaptation to environment in desert lizards.

The conditions:

A) Burrowing in soil to escape high temperature.

B) Losing heat rapidly from the body during high temperature

C) Bask in sun when temperature is low

D) Insulating body due to thick fatty dermis.

a) (A) and (C) b) (B) and (D)

c) (A) and (B) d) (C) and (D)

 

5. People who have migrated from the planes to an area adjoining Rohtang Pass about six months back

a) Have more RBC’s and their haemoglobin has a lower binding affinity to O2

b) Are not physically fit to play games like football

c) Suffer from altitude sickness with symptoms like nausea, fatigue, etc.,

d) Have the usual RBC count but then haemoglobin has very high binding affinity to O2

 

6. A biologist studies the population of eats in a barn. He found that the average natality was 250, average mortality is 240, immigration is 20 and emigration to be

30. The net increase in population

a) 10

b) 15

c) 05

d) Zero

 

7. An association of individuals of different species living in the same habitat and having functional interaction is

a) Biotic community

) Ecosystem

c) Population

d) Ecological niche

 

8. Gause’s principle of competitive exclusion states that:

a) More abundant species will exclude the less abundant species through competition

b) Competition for the same resources excludes species having different food preferences

c) No two species can occupy the same niche indefinitely for the same limiting resources

d) Larger organisms exclude smaller ones through competition

 

9. When does the growth rate of a population following the logistic model equal zero? The logistic model is given as dN/dt=rN(1-N/K

a) When N/K is exactly one

b) When N nears the carrying capacity of the habitat

c) When N/K equals zero

d) When dearth rate is greater than birth rate