ORGANISM AND POPULATION TOP 10 QUESTIONS - BIOLOGY ADDA BY KAIBALYA

   TOP 10 QUESTIONS ORGANISM AND POPULATION

 1.Carnivarous animal lions and leopards occupy the same niche but lion predate only larger animals and leopard takes smaller one . This mechanism of competition refers to as (ODISHA 2019)-

 a)Character displacement

 b)Altruism

 c)Resource partioning

 d)Competitive exclusion

2.Natality refers to (2018)-

 a)Birth rate

 b)Death rate

 c)Number of individual leaving the habitat

 d)Number of individual entering the habitat

3.Pneumatophores occurs in (2018)-

 a)Halophyte

 b)Free floating hydrophyte

 c)Carnivarous Plant

 d)Submerged hydrophyte

4.Niche is (2018)-

 a)All the biological factor in the organism environment

 b)The physical space where organism lives

 c)The range of temp that organism needs to live

 d)The functional role played by the organism where it lives

5. Between which among the following relationship is not an example of commensalism-

 a)Orchid and the tree which it grows

 b)Cattle egret and grazzing cattle

 c)Sea anemone and clwon fish

 d)Female wasp and fig species 

6.In a growing population of a country -

 a)Pre reproductive individual are more than the reproductive individuals 

 b)Reproductive individual are less than the post reproductive individuals 

 c)Reproductive = pre reproductive

 d)Pre reproductive < Reproductive 

7.Which one of the following plants show a very close relationship with a species of moth where none of the two can complete it's life cycle without the other -

 a)Hydrilla 

 b)Yucca

 c)Banana

 d)Viola

8.Which of the population interaction is widely used in medical science for production of antibiotics -

 a)Commensalism

 b)Mutualism 

 c)Parasitism

 d)Ammensalism 

9.Asymptote in a logistic growth curve is obtained when 

 a)K=N

 b)K>N

 c)K<N

 d)Value of r approches to 0

10.Plant which produce characterstics Pneumatophore and show vivipary belong to -

 a)Halophytes

 b)Psammophytes

 c)Hydrophytes

 d)Mesophytes 

ANSWERS - 

1.C

2.A

3.A

4.D

5.D

6.A

7.B

8.D

9.A

10.A

  

Ecological succession ncert NEET Biology Biology Adda by Kaibalya

                                        ECOLOGICAL SUCCESSION 

“Ecological succession is a series of changes that occur in an ecological community over time.”

1. Ecological succession is the steady and gradual change in a species of a given area with respect to the changing environment. It is a predictable change and is an inevitable process of nature as all the biotic components have to keep up with the changes in our environment.

2. The ultimate aim of this process is to reach equilibrium in the ecosystem. The community that achieves this aim is called a climax community. In an attempt to reach this equilibrium, some species increase in number while some other decreases.

3.In an area, the sequence of communities that undergo changes is called sere. Thus, each community that changes is called a seral stage or seral community.

TYPES OF ECOLOGICAL SUCCESSION --

There are following types of ecological succession.

1. Primary succession 

      Primary succession is the succession that starts in lifeless areas such as the regions devoid of soil or  the areas where the soil is unable to sustain life.

When the planet was first formed there was no soil on earth. The earth was only made up of rocks. These rocks were broken down by microorganisms and eroded to form soil. The soil then becomes the foundation of plant life. These plants help in the survival of different animals and progress from primary succession to the climax community.If this primary ecosystem is destroyed, secondary succession takes place.

2.Secondary succession 

Secondary succession occurs when the primary ecosystem gets destroyed. For eg., a climax community gets destroyed by fire. It gets recolonized after the destruction. This is known as secondary ecological succession. Small plants emerge first, followed by larger plants. The tall trees block the sunlight and change the structure of the organisms below the canopy. Finally, the climax community arrives.

3.Cyclic succession

This is only the change in the structure of an ecosystem on a cyclic basis. Some plants remain dormant for the rest of the year and emerge all at once. This drastically changes the structure of an ecosystem.

Seral Community -- “A seral community is an intermediate stage of ecological succession advancing towards the climax community.”

Cause of Ecological succession - The main causes of ecological succession include the biotic and climatic factors that can destroy the populations of an area. Wind, fire, soil erosion and natural disasters include the climatic factors.

Importance - 

Ecological succession is important for the growth and development of an ecosystem.

 It initiates colonization of new areas and recolonization of the areas that had been destroyed due to certain biotic and climatic factors.

Thus, the organisms can adapt to the changes and learn to survive in a changing environment.

HII THIS IS KAIBALYA FROM BIOLOGY ADDA BY KAIBALYA SHARED SOME INFORMATION RELATED TO ECOLOGICAL SUCCESSION WHICH IS IMPORTANT IN EXAMS . GOOD LUCK . JAY JAGANNATH.

Phosphorus Cycle - 12 th class , NCERT , ECOSYSTEM , BOARDS , NEET - Biology adda by kaibalya

               

              Phosphorus cycle

       Phosphorus is found in nature , in soil , as rock phosphate , in combination with calcium , iron and aluminium. It is the significant part of DNA , RNA and ATP . Human contain 80 percent of phosphorus in teeth and bones.

It is a very slow process.  Various weather processes help to wash the phosphorus present in the rocks into the soil . Phosphorus is absorbed by the organic matter in the soil which is used for various biological processes. It is a solid cycle and atomosphere does not play role in this cycle.

STEPS OF PHOSPHORUS CYCLE

Following are the important steps of phosphorus cycle:

1. Weathering
2. Absorption by Plants
3. Absorption by Animals
4. Return to the Environment through Decomposition 

1. 

WEATHERING - 

Phosphorus is found in the rocks in abundance. That is why the phosphorus cycle starts in the earth’s crust. The phosphate salts are broken down from the rocks. These salts are washed away into the ground where they mix in the soil.

ADSORPTION BY PLANT -

The phosphate salts dissolved in water are absorbed by the plants. However, the amount of phosphorus present in the soil is very less. That is why the farmers apply phosphate fertilizers on agricultural land.

The aquatic plants absorb inorganic phosphorus from lower layers of water bodies. Since phosphate salts do not dissolve in water properly, they affect plant growth in aquatic ecosystem.

ABSORPTION BY ANIMAL - 

The animals absorb phosphorus from the plants or by consuming plant-eating animals. The rate of the phosphorus cycle is faster in plants and animals when compared to rocks.

RETURN OF PHOSPHORUS THROUGH DECOMPOSITION-

When the plants and animals die they are decomposed by microorganisms During this process, the organic form of phosphorus is converted into the inorganic form, which is recycled to soil and water.

Soil and water will end up in sediments and rocks, which will again release phosphorus by weathering. Thus, the phosphorus cycle starts over.

HUMAN IMPACT ON PHOSPHORUS CYCLE

A number of human activities, use of fertilizers, artificial eutrophication, etc. has a great impact on the phosphorus cycle.

The phosphorus fertilizers increase the level of phosphorus in the soil. Overuse of these fertilizers reduces the fertility of the soil and is also harmful to the microorganisms present in the soil. When these are washed away into the nearby water bodies, they are hazardous to aquatic life.

During the shipping of food from farms to cities, the amount of phosphorus that is washed away in water causes eutrophication. This leads to the growth of algae. These form algal blooms or die, which is toxic to the aquatic ecosystem.

                Hii this is Kaibalya Nayak from from Biology adda by Kaibalya shared Phosphorus cycle which is important for various exams . Good luck have a nice day . Jay Jagannath. Do share with your friends.