|Organisms and Populations Refresher Course|
|Organisms and Populations Concepts Files|
|Organisms and Populations Master Files|
|Organisms and Populations Revision Note|
|Organisms and Populations Note 1|
|Organisms and Populations Note 2|
Organisms and Populations
Table of Content
- Organism and its Environment
- Major Abiotic Components
- Response to Abiotic Factors
- How does organism cope with the changing environment?
- Population Interactions
- Sun’s rotation and the tilt of its pivot cause yearly variations in the force and span of temperature, bringing forth the various seasons.
- These variations alongside yearly variations in precipitation, frames significant biomes, for example, tundra, rainforest, and desert.
- Temperature, soil, light, and water are the key components that prompt to such a great amount of variation in the physical and synthetic states of living spaces.
- Both abiotic (physic-synthetic) and biotic parts (competitions, pathogen, predators, parasites) describe the environment of a life form.
Fig: Abiotic and Biotic factors that influence ecosystems
- Temperature diminishes dynamically from equator moving towards the pole and high heights to > 50° C during summer in the tropical desert
- Thermal springs and remote ocean hydrothermal vents are exceptional with >100° C
- Temperature influences the BMR, the kinetics of enzymes, and other physiological activities
- Eurythermals: creatures which can endure an extensive variety of temperatures
- Stenothermals: creatures which can endure limited scope of temperatures
Fig: Steno-species exhibit a narrow tolerance zone while Eury- species exhibit a wide tolerance zone.
- Water is additionally a vital component that impacts the life of a living being
- The efficiency and conveyance of plants likewise rely on water
- The saltiness fluctuates in the oceanic environment:
- 5% in inland waters (new water)
- 30-35 percent in ocean water
- More than 100 percent in hyper saline tidal ponds
- Euryhaline: life forms which can endure extensive variety of saltiness
- Stenohaline: life forms which can endure limited scope of saltiness
Fig: A euryhaline fish
Fig: Yellow fin Tuna: A Stenohaline species
- Plants deliver sustenance by photosynthesis, which is conceivable only in light. Consequently, it is imperative for autotrophs.
- Plant species (bushes and herbs) adjusted for photosynthesis under shade.
- Sunlight is required for a photoperiodic reaction like blooming.
- Animals utilize diurnal and regular variations in light force and photoperiod as prompts for timing their migration, reproduction, and foraging.
- Properties of soil change as per the atmosphere, the weathering procedure.
- Aggregation, grain size, and soil composition decide the permeation and water holding limit of the soil.
- These trademarks alongside pH, mineral organization and geography decide to a huge degree the vegetation in any range.
- The silt trademark frequently decides the kind of benthic creature in oceanic environment.
Homeostasis; the procedure by which the creature keeps up a steady inner environment in regard to changing outside environment.
- Some life forms can keep up homeostasis physiological (occasionally behavioral too) meaning which guarantees steady body temperature, consistent osmotic focus.
- All mammals and birds and few lower spineless creatures are prepared to do such regulation i.e. osmoregulation and thermoregulation.
- Success of warm-blooded creatures is because of thermoregulation.
- We keep up a consistent body temperature of 37oC.
- When outside temperature is high we sweat abundantly and evaporative cooling happens to cut the body temperature down.
- In winter, because of low temperature outside our body, temperature falls underneath 37oC, we begin to shudder to create warmth to raise body temperature.
- Majority (99%) of creatures and plants can’t keep up a steady interior environment; their body temperature differs as indicated by surrounding temperature.
- In sea-going creatures the osmotic convergence of body liquid differs with surrounding water osmotic focus.
- All the above creatures and plants are just called as conformer.
Why the conformers are not evolved to become regulators?
- Thermoregulation is vigorously costly for some creatures.
- Humming birds and small creature like shrews can’t bear the cost of such a great amount of vitality for thermoregulation.
- Heat gain or heat loss is a component of surface range.
- Small creatures have bigger surface range with respect to their volume, they have a tendency to lose body warmth quickly when it is chilly outside; they then need to use much vitality to produce body warmth through digestion system.
- This is the reason little creatures are seldom found in Polar Regions.
Alternate response for difficult conditions is limited or stays for brief term.
- The creatures move away briefly from the distressing territory to a more affable zone and return when the unpleasant condition is over
- Birds move from the colder locale to hotter area
- Spores with thick walls are shaped in organisms to defeat unpleasant outside environment. Spores sprout in ideal condition.
- In higher plants, seeds and other vegetative conceptive structures are intended to hold over the stress. They diminish their metabolic movement and going into a condition of ‘dormancy’.
- Hibernation: amid winter creatures like bears escape in time
- Aestivation: creatures like snail and fish keep away from summer related issue like warmth and parching.
- Diapauses: numerous zooplanktons experience a phase of suspended advancement in unpleasant conditions.
- Adaptation: is any quality of the living being (behavioral, morphological, and physiological) that empowers the living being to survive and replicate in its living space.
- Kangaroo rat meets their water prerequisite from oxidation of fat
- Excrete extremely concentrated urine to save water
Fig: Adaptations of Kangaroo rat
- Leaf surfaces having thick cuticle
- Sunken stomata, both to decrease transpiration
- Have exceptional photosynthetic pathway (CAM), stomata shut amid daytime and stayed open amid night
- Opuntia has no leaf- they are diminished to spines
- Photosynthesis happens in flattened green stems
Fig: Desert Ground Plants
- Allen’s Rule: warm-blooded creatures from colder atmospheres, for the most part, have shorter ears and appendages to minimize warmth loss.
- Seals of polar oceanic oceans have blubber, a thick layer of fat underneath their skin that goes about as an insulator and decreases loss of body warmth.
Fig: Adaptations of Polar Bear in cold region
- An individual moving to high height (>3,500 meter), suffers from altitude sickness
- Symptoms created are heart palpitations, fatigue and nausea
- This is because of low air weight of high heights; the body is not able to get enough oxygen
- The body repays low oxygen accessibility by expanding the production of red blood cells
- The body repays by diminishing binding capacity of hemoglobin to oxygen by expanding rate of respiration
- Desert reptiles are conformers thus they adapt to the distressing environment by their behavioral adjustments:
- They lounge in the sun and assimilate warmth when their body temperature drops beneath the safe place in winter
- Move towards shade when the surrounding temperature increases
- Some species tunnel into the soil to conceal and escape from over the ground warmth
- Population: a gathering of individual living in a very much characterized topographical range, share or go after comparable assets, possibly interbreed.
- Birth rate refers to per capita births and death rate alludes to per deaths.
- Another property is sex proportion. The proportion between the male- female in a population.
- If the age conveyance is plotted for a population the subsequent structure is called age pyramid.
- The state of the pyramids mirrors the development status of the population like developing, stable or declining.
- The population size is all the more in fact called as population density.
Fig: Diagram depicts the stage of Growth
- Percent cover
- Counting the number
- Pug marks and fecal pellets for tiger census
- The population size changes relying upon food accessibility, predation force and lessen climate.
- Population estimate vacillated because of changes in four fundamental procedures, two of which (Natality and immigration) contribute an expansion in population density and two (mortality and emigration) to a diminishing.
- Natality: number of birth in given period in the population.
- Mortality: number of deaths in the population in a given timeframe.
- Immigration is the quantity of people of same species that have come into the territory from somewhere else amid a given timeframe.
- Emigration: number of people of the population who left the territory and gone somewhere else amid a given timeframe and age.
- If “N” is the population density at time ‘t’, then its density at time t + 1 is:
N1+t = Nt + [( B+1) – (D + E)]
Fig: Verhulst Pearl Logistic Growth
dN/dt = rN [(K – N)/K]
Where B = the number of births
D = the number of deaths
I = the number of immigrants
E = the number of Emigrants
K = Carrying capacity (The maximum population size that an environment can sustain)
N = Population Density
t = Time period
r = Intrinsic rate of natural increase
- The Exponential growth equation is Nt = N0ert
- N0 = Population density at time zero
- Nt = Population density after time t
- e = the base of natural logarithms (2.71828)
- r = intrinsic rate of natural increase
- Exponential growth (‘J’ shape curve is obtained)
At the point when assets are not constraining the development
- Any species development exponentially under boundless assets conditions can achieve gigantic population densities in a brief span
- Growth is not all that sensible and realistic
- Verhulst-Pearl Logistic Growth is described by the following equation
dN/dt = rN (K–N / N)
- WhereK = Carrying capacity
- r = Intrinsic rate of natural increase
- N = Population density at time t
Fig: Exponential vs Logistic Growth
- When reactions are restricting the Growth.
- Resources for development for most creature populations are limited and get to be distinctly restricting.
- The logistic growth model is a more practical one.
Fig: Logistic Growth Curve
- Higher trophic level organisms (predator) sustains on the creature of lower trophic level (prey) is known as the predation
- Even the herbivores are not altogether different from the predator
- Predator goes about as a section for the exchange of vitality crosswise over the trophic level
- Predators monitor prey populations
- Exotic species have no normal predator subsequently they grow quickly. (thorny pear prickly plant presented in Australia made issue)
- Predators additionally help in keeping up species assorted qualities in a group, by lessening the force of rivalry among contending prey species. (Pisaster starfish field experiment)
Defense developed by prey against predators
- Insects and frogs are obscurely shaded (camouflaged) to abstain from being recognized by the predator
- Some are noxious and in this way maintained a strategic distance from by the predators
- Monarch butterfly is exceptionally disagreeable to its predator (flying creature) because of the nearness of unique concoction in its body. The substance procured by nourishing a harmful weed amid caterpillar stage.
- Thorns in Cactus and Acacia are a morphological method for protection
- Many plants create and store some substance which makes the herbivore wiped out if eaten, distress reproduction, digestion, and interferes feeding even slaughter the predators
- Calotropis produces noxious cardiovascular glycosides against herbivores
- Nicotine, opium, caffeine, strychnine, quinine, and so on are created by plant as resistances against the nibblers and browsers
- Interspecific rivalry is a powerful drive in natural development.
- Competition, for the most part, happens when firmly related species go after similar assets that are restricting, yet this not by any stretch true or genuine:
- Firstly: absolutely random species could likewise go after similar assets.
- American lakes going by flamingoes and inhabitant angles have their normal food, zooplanktons.
- Secondly: assets need not be restricting for a rivalry to happen.
- Abingdon tortoise in Galapagos Islands got to be distinctly wiped out within 10 years after goats were presented on the island, because of more prominent perusing capacity.
- Parasitic method of life guarantees free space and food
- Some parasites are host-particular (one parasite has a solitary host) in a manner that both host and parasite tend to co-develop
- Loss of superfluous sense organs
- Presence of sucker or organs to stick on to the host
- Loss of stomach related framework
- High reproductive limit
- Parasites having at least one intermediate host or vectors to encourage parasitisation of its essential host
- Liver fluke has two hosts (snail and a fish) to finish its life cycle
Effects on the host:
- Parasite dependably harms the host
- Reduce its population density
- They diminish the survival, development and generation of the host
- They make the host more defenseless against the predators, by making it physically frail
• Ectoparasite: sustains on the outer surface of the host.
- Lice on human
- Marine fish pervaded with copepods
- Ticks on dogs
- Cuscutaa parasitic plant develop on hedge plants
• Endoparasites: are those that live inside the host body at various locales:
- Life cycle is much complex
- Highly created reproductive framework
- Morphological and anatomical components are extraordinarily disentangled
• Brood parasitism:
- Special sort of parasitism found in birds
- The egg of the parasite is fundamentally the same as with the egg of the host
- The parasitic winged creatures lay its eggs in the home of its host and let the host hatch them
- Cuckoo lays eggs in the nest of the crow
Fig: Parasitism versus Predation
- This is the association in which one species benefits and the other is neither profited nor hurt
- Clown fish living in the tentacles of the sea anemone
- Orchids developing as an epiphyte on a mango branch
- Cattle Egret and nibbling steers
- Barnacles on the back of whales
communication between two living being, both are similarly profited, nobody is hurt.
- Lichen: a mycobiont and a Phycobiont
- Mycorrhiza: relationship amongst fungi and base of the higher plant
- Fig trees and its pollinating specialist wasp
- Pollinating bugs and blossoming plants
Fig: The most commonly known mutualistic relationship is the honey bee and the flower though there are many different types of mutualistic relationships.
Sexual Deceit is a type of pseudo copulation. Pseudo copulation describes behaviors similar to copulation that serve a reproductive function for one or both participants but do not involve actual sexual union between the individuals.
- Mediterranean orchid Ophrys utilizes ‘sexual deceit’
- The male honey bee pulled into what it sees as a female, “pseudo copulates” with the bloom, however, does not get any advantages
- Petal of the bloom looks like the female honey bee
Fig: Sexual Deception by Ophrys apifera