intro-hostory and discovery-characteristics of phytochrome-chemical nature of phytochrome-mode of action-mechanism-phytochrome mediated physiological responses-phytochrome is a pigment system:some evidences-role of phytochrome
Inheritance due to genes located in cytoplasm is called cytoplasmic inheritance.
Since genes governing traits showing cytoplasmic inheritance are located outside the nucleus and in the cytoplasm, they are referred to as plasmagenes.
Speciation is the evolutionary process by which reproductively isolated biological populations evolve to become distinct species.There are few mechanisms through which this process can be well understood.
intro-hostory and discovery-characteristics of phytochrome-chemical nature of phytochrome-mode of action-mechanism-phytochrome mediated physiological responses-phytochrome is a pigment system:some evidences-role of phytochrome
Inheritance due to genes located in cytoplasm is called cytoplasmic inheritance.
Since genes governing traits showing cytoplasmic inheritance are located outside the nucleus and in the cytoplasm, they are referred to as plasmagenes.
Speciation is the evolutionary process by which reproductively isolated biological populations evolve to become distinct species.There are few mechanisms through which this process can be well understood.
Biotic factors also regulate the size of populations more intensely. Finally, the influence of biotic interactions can occur at two different levels. Interspecific effects are direct interactions between species, and the intraspecific effects represent interactions of individuals within a single species.
In flowering plants, the term "apomixis" is commonly used in a restricted sense to mean agamospermy, i.e. clonal reproduction through seeds.
Thus, Apiomixis can be defined as the development of embryo with or without embryosac formation but without fertilization.
It is the fundamental law of population genetics and provides the basis for studying Mendelian populations ( Mendelian population: A group of sexually inbreeding organisms living within a circumscribed area). It describes populations that are not evolving.
This presentation intends to give a bird's eye view of different abiotic ecological factors with special reference to light, temperature, fire and wind and their impact on ecosystem.
PHOTOPERIODISM IN PLANTS
• The concept of photoperiodism was given by W.W. Garner & H.A. Allard of the U.S Department of Agriculture, studied flowering in Maryland's mammoth variety of Tobacco plant in 1920.
• ‘PHOTOPERIODISM':-derived from 2 Greek words i.e.,'photos' (light) & periods (length of time).
• With a few exceptions, virtually all organisms (plant & animals) need exposure to light for a given number of hours per day for a variety of growth and reproductive functions. This day length is called PHOTOPERIOD & the phenomenon is called PHOTOPERIODISM.
• The flowering plant comprises 2 phases i.e, vegetative & reproductive.
• Under an appropriate photoperiod, plant switches from vegetative to reproductive phase, responding to the synthesis of flowering hormones & its subsequent translocation to buds. (Bartholomew,1977)
• The effect of daily duration of light hours(& dark periods) on the growth & development of plants, especially flowering is called photoperiodism.
CRITICAL DAY LENGTH
• Critical day length is the photoperiod required to induce flowering.
• It varies from species to species.
• e.g-Xanthium (SDP) requires a critical day length of 15.5hrs (15.5 light/8.5 dark).
• Critical photoperiod mustn't be exceeded in short-day plants & should always be exceeded in long-day plants.
• A single photoperiodic cycle that induces flowering-Inductive cycle & its effect is called Photoperiodic induction.
Depending upon the duration of the photoperiod, plants are classified into 3 categories:
1. Short Day Plants (SDP):
These plants require a relatively short daylight period (usually 8-10 hours) and a continuous dark period of about 14-16 hours for subsequent flowering.E.g.:-Strawberry, coffee, pineapple, etc.
o These plants are also known as long-night-plants.
2. Long day plants (LDP):
These plants require a longer daylight period (usually 14-16 hours) in a 24 hours cycle for subsequent flowering.
o Also called as short night plants.
E.g.:-Apple, passion fruit, etc..
3. A day-neutral plant (DNP):
This plants flower in all photoperiods ranging from 5 hrs to
24 hrs of continuous exposure.
e.g.:- Banana, guava, tomato, brinjal, etc…
-Dual Day Length Plants
Long Short Day Plants(LSDP):
These are short-day plants but must be exposed to long days during early periods of growth for subsequent flowering.
e.g.:- species of Bryophyllum, night jasmine, etc..
Short-Long Day Plants(SLDP):
These are long-day plants but must be exposed to short days during early periods of growth for subsequent flowering.
e.g.:- Wheat (Triticum), Rye (Secale), etc.
-MECHANISM OF PHOTOPERIODISM
-Florigen concept
-Phytochrome concept
-IMPORTANCE OF PHOTOPERIODISM
ROOT HAIR DEVELOPMENT IN PLANTS:
structure and development of root hairs, Initiation and molecular genetics of root hair, functions of root hairs.
complete topic from authentic websites. Essential for for all life science students.
Biotic factors also regulate the size of populations more intensely. Finally, the influence of biotic interactions can occur at two different levels. Interspecific effects are direct interactions between species, and the intraspecific effects represent interactions of individuals within a single species.
In flowering plants, the term "apomixis" is commonly used in a restricted sense to mean agamospermy, i.e. clonal reproduction through seeds.
Thus, Apiomixis can be defined as the development of embryo with or without embryosac formation but without fertilization.
It is the fundamental law of population genetics and provides the basis for studying Mendelian populations ( Mendelian population: A group of sexually inbreeding organisms living within a circumscribed area). It describes populations that are not evolving.
This presentation intends to give a bird's eye view of different abiotic ecological factors with special reference to light, temperature, fire and wind and their impact on ecosystem.
PHOTOPERIODISM IN PLANTS
• The concept of photoperiodism was given by W.W. Garner & H.A. Allard of the U.S Department of Agriculture, studied flowering in Maryland's mammoth variety of Tobacco plant in 1920.
• ‘PHOTOPERIODISM':-derived from 2 Greek words i.e.,'photos' (light) & periods (length of time).
• With a few exceptions, virtually all organisms (plant & animals) need exposure to light for a given number of hours per day for a variety of growth and reproductive functions. This day length is called PHOTOPERIOD & the phenomenon is called PHOTOPERIODISM.
• The flowering plant comprises 2 phases i.e, vegetative & reproductive.
• Under an appropriate photoperiod, plant switches from vegetative to reproductive phase, responding to the synthesis of flowering hormones & its subsequent translocation to buds. (Bartholomew,1977)
• The effect of daily duration of light hours(& dark periods) on the growth & development of plants, especially flowering is called photoperiodism.
CRITICAL DAY LENGTH
• Critical day length is the photoperiod required to induce flowering.
• It varies from species to species.
• e.g-Xanthium (SDP) requires a critical day length of 15.5hrs (15.5 light/8.5 dark).
• Critical photoperiod mustn't be exceeded in short-day plants & should always be exceeded in long-day plants.
• A single photoperiodic cycle that induces flowering-Inductive cycle & its effect is called Photoperiodic induction.
Depending upon the duration of the photoperiod, plants are classified into 3 categories:
1. Short Day Plants (SDP):
These plants require a relatively short daylight period (usually 8-10 hours) and a continuous dark period of about 14-16 hours for subsequent flowering.E.g.:-Strawberry, coffee, pineapple, etc.
o These plants are also known as long-night-plants.
2. Long day plants (LDP):
These plants require a longer daylight period (usually 14-16 hours) in a 24 hours cycle for subsequent flowering.
o Also called as short night plants.
E.g.:-Apple, passion fruit, etc..
3. A day-neutral plant (DNP):
This plants flower in all photoperiods ranging from 5 hrs to
24 hrs of continuous exposure.
e.g.:- Banana, guava, tomato, brinjal, etc…
-Dual Day Length Plants
Long Short Day Plants(LSDP):
These are short-day plants but must be exposed to long days during early periods of growth for subsequent flowering.
e.g.:- species of Bryophyllum, night jasmine, etc..
Short-Long Day Plants(SLDP):
These are long-day plants but must be exposed to short days during early periods of growth for subsequent flowering.
e.g.:- Wheat (Triticum), Rye (Secale), etc.
-MECHANISM OF PHOTOPERIODISM
-Florigen concept
-Phytochrome concept
-IMPORTANCE OF PHOTOPERIODISM
ROOT HAIR DEVELOPMENT IN PLANTS:
structure and development of root hairs, Initiation and molecular genetics of root hair, functions of root hairs.
complete topic from authentic websites. Essential for for all life science students.
Honest Reviews of Tim Han LMA Course Program.pptxtimhan337
Personal development courses are widely available today, with each one promising life-changing outcomes. Tim Han’s Life Mastery Achievers (LMA) Course has drawn a lot of interest. In addition to offering my frank assessment of Success Insider’s LMA Course, this piece examines the course’s effects via a variety of Tim Han LMA course reviews and Success Insider comments.
How to Make a Field invisible in Odoo 17Celine George
It is possible to hide or invisible some fields in odoo. Commonly using “invisible” attribute in the field definition to invisible the fields. This slide will show how to make a field invisible in odoo 17.
Operation “Blue Star” is the only event in the history of Independent India where the state went into war with its own people. Even after about 40 years it is not clear if it was culmination of states anger over people of the region, a political game of power or start of dictatorial chapter in the democratic setup.
The people of Punjab felt alienated from main stream due to denial of their just demands during a long democratic struggle since independence. As it happen all over the word, it led to militant struggle with great loss of lives of military, police and civilian personnel. Killing of Indira Gandhi and massacre of innocent Sikhs in Delhi and other India cities was also associated with this movement.
Palestine last event orientationfvgnh .pptxRaedMohamed3
An EFL lesson about the current events in Palestine. It is intended to be for intermediate students who wish to increase their listening skills through a short lesson in power point.
Read| The latest issue of The Challenger is here! We are thrilled to announce that our school paper has qualified for the NATIONAL SCHOOLS PRESS CONFERENCE (NSPC) 2024. Thank you for your unwavering support and trust. Dive into the stories that made us stand out!
Synthetic Fiber Construction in lab .pptxPavel ( NSTU)
Synthetic fiber production is a fascinating and complex field that blends chemistry, engineering, and environmental science. By understanding these aspects, students can gain a comprehensive view of synthetic fiber production, its impact on society and the environment, and the potential for future innovations. Synthetic fibers play a crucial role in modern society, impacting various aspects of daily life, industry, and the environment. ynthetic fibers are integral to modern life, offering a range of benefits from cost-effectiveness and versatility to innovative applications and performance characteristics. While they pose environmental challenges, ongoing research and development aim to create more sustainable and eco-friendly alternatives. Understanding the importance of synthetic fibers helps in appreciating their role in the economy, industry, and daily life, while also emphasizing the need for sustainable practices and innovation.
Acetabularia Information For Class 9 .docxvaibhavrinwa19
Acetabularia acetabulum is a single-celled green alga that in its vegetative state is morphologically differentiated into a basal rhizoid and an axially elongated stalk, which bears whorls of branching hairs. The single diploid nucleus resides in the rhizoid.
Embracing GenAI - A Strategic ImperativePeter Windle
Artificial Intelligence (AI) technologies such as Generative AI, Image Generators and Large Language Models have had a dramatic impact on teaching, learning and assessment over the past 18 months. The most immediate threat AI posed was to Academic Integrity with Higher Education Institutes (HEIs) focusing their efforts on combating the use of GenAI in assessment. Guidelines were developed for staff and students, policies put in place too. Innovative educators have forged paths in the use of Generative AI for teaching, learning and assessments leading to pockets of transformation springing up across HEIs, often with little or no top-down guidance, support or direction.
This Gasta posits a strategic approach to integrating AI into HEIs to prepare staff, students and the curriculum for an evolving world and workplace. We will highlight the advantages of working with these technologies beyond the realm of teaching, learning and assessment by considering prompt engineering skills, industry impact, curriculum changes, and the need for staff upskilling. In contrast, not engaging strategically with Generative AI poses risks, including falling behind peers, missed opportunities and failing to ensure our graduates remain employable. The rapid evolution of AI technologies necessitates a proactive and strategic approach if we are to remain relevant.
1. St. Xavier’s College, Mahuadanr
Dr. Emasushan Minj (Assistant Professor) Depatment of Botany Page 1
Functional aspects of ecosystem
Unit-9
Core Course-9
Energy Flow
The Earth is an open system of energy. It is the key function in the ecosystem.
The operation of an ecosystem is regular with the law laws of thermodynamics that deals
with the relationship between energy and matter in a system.
The behaviour of the energy in the ecosystem is based on two basic laws of
thermodynamics.
The first law of thermodynamics, which states that energy cannot be created nor
destroyed but only transformed. The first law of thermodynamics is also called as law of
conservation of energy.
The sun is the ultimate source of energy for almost all ecosystems present on the earth.
Photosynthetic organisms convert solar energy to chemical energy, but the total amount
of energy does not change.
The total amount of energy stored in organic molecule synthesized by the process of
photosynthesis plus the amounts dissipated as heat must equal the total solar energy
intercepted by the photosynthetic organisms.
In other words, energy may change form (from radiant to chemical) but not amount.
During energy transformation, some amount of energy is converted to form that’s usable.
In most cases, this unusable energy takes the form of heat.
Energy in the form of heat does not do work it goes to increase the randomness of the
universe. The degree of randomness or disorder in the system is known as entropy.
2. St. Xavier’s College, Mahuadanr
Dr. Emasushan Minj (Assistant Professor) Depatment of Botany Page 2
The second law of thermodynamics, states that every energy transformation that takes
place will increase the entropy of the universe in other words, every transformation
cannot be hundred percent efficient some energy is always lost as heat.
In ecosystems, energy flows unidirectionally. The fraction of incoming solar radiant
energy that the producers capture is small. Only about 1- 5% energy is incident solar
radiation 2-10% of PAR (Photosynthetically Active Radiant) is actually captured by the
photosynthetic processes. The solar energy not used for photosynthesis is immediately
converted to heat.
The flow of energy through an ecosystem
The energy that enters the ecosystem as solar energy (radiant energy) and is then passed a long as chemical energy to successive
trophic level. At its step energy is diverted meaning that the chemical energy available to each trophic level is less than that
available to the preceding trophic level. Death at each level transfers energy to decomposers. Energy lost as heat at each trophic
level is return to the external environment.
Energy flow model
A simplified representation of energy flow through ecosystem has been made in figure.
The model attempts to recognize the various inputs and weights of energy.
3. St. Xavier’s College, Mahuadanr
Dr. Emasushan Minj (Assistant Professor) Depatment of Botany Page 3
Two aspects with respect to energy flow in the ecosystem need careful consideration.
• First, the energy flows unidirectionally, it cannot be transferred in the
reverse direction.
• Second, the amount of energy flow decreases with successive trophic
levels.
Ecological efficiencies
In ecosystems, living organisms are linked together by feeding relationship.
Producers have the ability to fix carbon through photosynthesis via chlorophyll in their
leaves.
Herbivores are the primary consumers of organic molecule fixed by the producers.
Secondary consumers live on the organic molecule of the herbivorous.
There may be several levels of carnivorous in any one ecosystem search in such cases the
ultimate level will be occupied by the top carnivorous.
4. St. Xavier’s College, Mahuadanr
Dr. Emasushan Minj (Assistant Professor) Depatment of Botany Page 4
The final groups of organism in an ecosystem are decomposers, bacteria and fungi which
can break down the complex organic chemicals of death dead organism or dead material
and waste products.
Percentage of energy in the biomass produced by one trophic level that is incorporated
into the biomass produced by the next higher trophic level is called ecological efficiency.
It is also known as transfer efficiency or Lindeman’s efficiency.
The proportions of net primary producer production that flow along the possible energy
pathways depend on transfer efficiencies in the way energy is used and passed from one
step to the next.
Knowledge of three categories of transfer efficiency is required to predict the pattern of
energy flow. These are consumption efficiency (CE), assimilation efficiency (AE) and
production efficiency (PE).
Consumption efficiency or exploitation efficiency is the percentage of total productivity
available at one trophic level (Pn-1) that is actually consumed by a trophic compartment
one level up (In).
In the case of secondary consumer, it is the percentage of herbivores productivity eaten
by carnivores. Consumption efficiencies of herbivores are very low, reflecting either the
difficulty of utilizing plant material or the low herbivores densities.
Assimilation efficiency is the percentage of food energy taken into the guts of consumers
in a trophic compartment (In) that assimilated across the gut wall (An) and becomes
available for incorporation into growth or used to do work. The reminder is lost as feces
and enters the base of decomposer system.
5. St. Xavier’s College, Mahuadanr
Dr. Emasushan Minj (Assistant Professor) Depatment of Botany Page 5
Carnivorous have higher assimilation efficiency approx. 80% than herbivores that is
about 20-50% because animal food is more easily digested than plant food. In aquatic
ecosystem, autotrophs are mostly of small biomass but very low indigestible matters as
compared to their counter parts in the terrestrial ecosystem. Hence, herbivores
assimilation efficiency is higher in aquatic ecosystem than in terrestrial ecosystem.
Production efficiency is the percentage of assimilated energy (An) that is incorporated
into new biomass (Pn). The remainder is entirely lost to the community as respiratory heat.
Production efficiency is also known as net productivity efficiency or tissue growth
efficiency varies mainly according to taxonomic class of the organism concerned. In
vertebrates in general, have high efficiency (30- 40%) and among the vertebrates cold
blooded animals have intermediate values of PE around 10%. In warm-blooded animals
come with high energy expenditure associated with maintenance maintaining a constant
temperature, convert only one to 2% of assimilated energy into production. Similarly,
herbivorous tend to have higher production efficiency but lower assimilation efficiency
than carnivores.
Trophic transfer efficiency
Lindeman's law of tropic transfer efficiency or simply tropic efficiency states that the
efficiency of energy transfer from one trophic level to the next is about 10% i.e. about 10% off
the net primary productivity of producer ends up as herbivores, about 10% of the net productivity
of herbivores end up as primary carnivorous and so on.
In other words about 90% of energy available at one trophic level typically is not
transferred to the next. This loss is multiplied over the length of a food chain. For example, if
6. St. Xavier’s College, Mahuadanr
Dr. Emasushan Minj (Assistant Professor) Depatment of Botany Page 6
10% of available energy is transferred from primary producers to primary consumers and 10% of
that energy is transferred to secondary consumers then only 1% of net primary production is
available for next consumer i.e. 10% of 10%.
Nutrient cycling
Earth is a closed system with respect to matter.
Every matter used by living organisms pass between the biotic and abiotic components of
biosphere.
Nutrient cycling is the movement or cycling movement of matter through the system.
It is subdivide the system into to atmosphere, hydrosphere, lithosphere and biosphere.
By matter we mean elements such as carbon, nitrogen, oxygen or molecules such as
water.
The movement of matter between these parts of system is generally termed as a
biogeochemical cycle.
Gaseous and sedimentary nutrient cycles
In gases nutrient cycle, the atmosphere constitutes a major reservoir of element that in a
gaseous phase.
Such cycle show little or no permanent change in the distribution and abundance of the
element.
Carbon and hydrogen are main representatives of biogeochemical cycle with a prominent
gaseous phase.
In a sedimentary cycle, the major reservoir is the lithosphere from where the elements are
released by weathering.
7. St. Xavier’s College, Mahuadanr
Dr. Emasushan Minj (Assistant Professor) Depatment of Botany Page 7
The sedimentary cycles represented by phosphorus, Sulfur, iodine and other biological
important elements have a tendency to stagnate.
In such cycles, a portion of the supply may accumulate in large quantities as in the deep
ocean sediments and thereby become unreachable to organisms and to continual cycle.
Some of the elements that are characterized by sedimentary cycle do have a gaseous
phase, Sulfur and Iodine, but these phases are insignificant as there is no large gaseous
reservoir.
Global and local nutrient cycles
An elements specific route v biogeochemical cycle varies with particular element and the
trophic structure of the ecosystem.
There are two general categories of biogeochemical cycle global and local.
Gaseous form of carbon, oxygen, Sulfur and nitrogen occur in the atmosphere and cycles
of these elements are essentially global.
Other, less mobile elements including phosphorus, potassium and calcium are generally
cycle in localized scale. Soil is the main abiotic reservoir of these elements.
General model of nutrient cycling
A general model of nutrient cycling includes the main reservoir of elements and the
processes that transferred elements between reservoirs.
Each reservoir is defined by characteristics; whether it contains organic or inorganic
materials and whether or not the materials are directly available for used by organisms.
The nutrients in living organisms and in detritus are available to other organisms when
consumers feed and when detritivores consume nonliving organic matter.
8. St. Xavier’s College, Mahuadanr
Dr. Emasushan Minj (Assistant Professor) Depatment of Botany Page 8
Some materials are moved from the living or organic reservoir to the fossilized organic
reservoir, when dead organisms are buried by sedimentation over millions of years
becomes coal, peat. The nutrients in these deposits cannot be assimilated directly.
Inorganic materials dissolved in water or present in the soil or air are available for use.
Organisms assimilate material from this reservoir directly and return chemicals to it
through the relatively rapid processes of cellular respiration, excretion and decomposition.
Although organisms cannot directly tap into the inorganic elements tied up in the rocks,
these nutrients may slowly become available through weathering and erosion.
Similarly, unavailable organic materials move into the available reservoir of inorganic
nutrients when fossil fuels are burned, releasing exhaust into the atmosphere.
9. St. Xavier’s College, Mahuadanr
Dr. Emasushan Minj (Assistant Professor) Depatment of Botany Page 9
Carbon cycle
Photosynthesis and respiration are the two opposing processes that drive the global
carbon cycle.
It is predominantly a gaseous cycle with CO2 as the main vehicle of flux between the
atmosphere, hydrosphere and biota.
Terrestrial plants use atmospheric CO2 as their carbon source for photosynthesis, whereas
aquatic plant use dissolved carbonates such as carbon from hydrosphere.
In addition, carbon finds its way into Island waters and oceans as bicarbonate resulting
from the weathering of calcium rich rock search as limestone and chalk.
Respiration by plants, animal and microorganisms release the carbon locked in
photosynthetic products back to the atmosphere and hydrosphere carbon compartments.
10. St. Xavier’s College, Mahuadanr
Dr. Emasushan Minj (Assistant Professor) Depatment of Botany Page 10
Nitrogen cycle
The atmospheric phase is major in the global net nitrogen cycle.
In nitrogen cycle nitrogen is converted between its various chemical forms.
This transformation carried out by both biological and non biological processes.
The important processes in the nitrogen cycle include nitrogen fixation ammonia fixation,
nitrification and denitrification.
Nitrogen fixing involves the conversion of N2 by bacteria to ammonium ions.
Atmospheric nitrogen is also fixed by lightning discharge during storm and reaches the
ground as nitric acid dissolved in rainwater but only about 3-4% of fixed nitrogen derives
from this pathway.
Ammonification involves decomposition of organic nitrogen to ammonium ion. In
nitrification, ammonium ion is converted to nitrate nitrite and nitrate by nitrifying
bacteria.
Denitrification is the reduction of nitrates into nitrogen gas. The process is performed by
bacterial species such as pseudomonas and clostridium in anaerobic conditions.
11. St. Xavier’s College, Mahuadanr
Dr. Emasushan Minj (Assistant Professor) Depatment of Botany Page 11
Phosphorus cycle
Phosphorus occur in rocks and ocean sediments and in dissolved form in rivers, lake and
ocean water.
Weathering of rock gradually adds phosphorus to soil some leached into groundwater and
surface water and main event will reach the sea.
The phosphorus cycle may be described as an ‘open’ cycle because of the general
tendency of mineral phosphorus to be carried from the land to the ocean.
A typical phosphorus atom released from the rocks by chemical weathering may enter
and cycle within the terrestrial community for years, or centuries before it is carried via
groundwater into a stream, where it takes part in the nutrient spiraling.
12. St. Xavier’s College, Mahuadanr
Dr. Emasushan Minj (Assistant Professor) Depatment of Botany Page 12
Sulfur cycle
In the global phosphorus cycle, lithospheric phase is predominant whereas in the nitrogen
cycle, atmospheric phase is more important.
Sulfur by contrast has atmospheric and ethers ferric phases of similar magnitude. Three
natural biogeochemical cycle processes release sulfur into the atmosphere:
• The formation of volatile compound dimethyl sulfide
• Anaerobic respiration bi sulfate reducing bacteria and
• Volcanic activity
The weathering of rocks provides about half the sulfur draining of the land into rivers and
lakes the reminder driving from atmospheric sources.
The sulfur takes taken up taken up by plants; past along food chain and wire
decomposition processes becomes available again to the plants.
The combustion of fossil fuel is the major human activity e to the global sulfur cycle.
13. St. Xavier’s College, Mahuadanr
Dr. Emasushan Minj (Assistant Professor) Depatment of Botany Page 13
Summary
In the flow of energy and inorganic nutrients through the ecosystem of few
generalizations can be made:
➢ The ultimate source of energy is the sun.
➢ The ultimate fate of energy in ecosystem is to be lost as heat.
➢ Energy and nutrients are passed from organism to organism through the food
chain as one organism eats another.
➢ Decomposers remove the last energy from the remains of organisms.
➢ In organic nutrients are cycle, energy is not.