ORGANISMS AND POPULATION

                   ORGANISMS AND POPULATION

1. INTRODUCTION 

    Father of Ecology in India:- Ramdeo Mishra

    Father of Ecology:- Alexander von Helmold

    Father of Modern Ecology:- Eugene Odum

1. Ecology is the study of the interactions between living organisms and their environment. It is a branch of science that seeks to understand the complex relationships between living organisms and their environment.

2. Ecology was first introduced by the German zoologist Ernst Haeckel in 1866. He proposed the term “oekologie” to describe the relationships between organisms and their environment.

3. Since then, many scientists have contributed to the field of ecology, such as Charles Darwin, Alfred Wallace, Henry David Thoreau, and Rachel Carson.

4. Ecology is an important field of science that helps us understand the impacts of human activities on the environment and how to protect and restore natural habitats. It also provides insights into the impact of climate change on ecosystems. 

2.ECOLOGY 

2.1Habitat and Niche

Habitat:

• The physical environment where an organism lives

• Includes the air, water, food, shelter, and space available to the organism

Niche:

• The role an organism plays in its environment

• Includes the organism's diet, behavior, and interactions with other species

3. Organisms and it's Environment 

3.1 Major Abiotic factors 

1. Temperature: Temperature is a major abiotic factor that affects the environment and the organisms living within it.

2. Light: Light is an important abiotic factor as it provides energy for photosynthesis, which is essential for plant growth.

3. Water: Water is a key abiotic factor as it is essential for life and most organisms need it to survive.

4. Soil: Soil is an important abiotic factor as it provides nutrients and minerals for plants and other organisms.

5. Wind: Wind affects the environment and the organisms living within it. It can cause erosion and transport pollen and other particles.

6. Atmospheric Pressure: Atmospheric pressure affects the environment and the organisms living within it. It can affect temperature and the movement of air.

3.2 Responses to abiotic factors

1. Organisms respond to abiotic factors in a variety of ways, such as behavioral, physiological, and morphological adaptations.

2. Behavioral adaptations may include changes in activity patterns, migration, and hibernation.

3. Physiological adaptations involve changes in the organism's internal systems, such as adjusting its body temperature or water balance.

4. Morphological adaptations involve changes in the organism's physical structure, such as the development of thicker fur or a longer beak.

5. Abiotic factors can also affect the environment in which an organism lives, such as the availability of resources or the presence of predators.

6. Organisms may respond to these environmental changes by altering their behavior, moving to a more suitable habitat, or evolving in response to the new conditions.

4.Adaptations

4.1 Adaptations in desert plants

1. Reduced Surface Area: Desert plants have adapted to reduce their surface area, which helps them to conserve water. 

2. Waxy Cuticles: Desert plants have thick, waxy cuticles on their leaves and stems to reduce water loss. 

3. Deep Roots: Desert plants have adapted to grow deep roots that can access underground water sources. 

4. Thick Stems: Desert plants have adapted to have thick and succulent stems that can store water. 

5. Small Leaves: Desert plants have adapted to have small leaves to reduce water loss. 

6. Heat Tolerance: Desert plants have adapted to tolerate high temperatures and direct sunlight. 

7. Drought Tolerance: Desert plants have adapted to survive long periods of drought. 

8. Photosynthesis: Desert plants have adapted to increase their photosynthesis efficiency to reduce water loss.

4.2 Adaptations in kangaroo rats

Kangaroo rats have adapted to survive in dry, arid environments: 

• They have large back feet, which they use to jump up to 3 feet in the air, allowing them to quickly escape predators. 

• They have fur-lined cheek pouches to store food and water, which they use to survive in areas with scarce resources. 

• They have a special kidney structure that allows them to conserve water, reducing their need to drink. 

• They can survive on a diet of seeds and other plant material, and can go long periods without food or water. 

• They are nocturnal, reducing the risk of being seen by predators. 

• They are able to enter a state of torpor, reducing their metabolic rate and conserving energy.

4.3 Altitude Sickness (Phenotypic Adaptations)

Altitude sickness is a condition that occurs when a person climbs to a high altitude too quickly. It is caused by a lack of oxygen at high altitudes. Symptoms of altitude sickness include headache, nausea, dizziness, fatigue, and difficulty breathing.

Key Points: 

- Altitude sickness occurs when a person climbs to a high altitude too quickly. 

- It is caused by a lack of oxygen at high altitudes. 

- Symptoms include headache, nausea, dizziness, fatigue, and difficulty breathing. 

- Phenotypic adaptations can help the body to acclimatize and adjust to the altitude. 

- These adaptations include increased lung capacity, increased red blood cell production, and increased production of hormones to help the body adjust to the environment.

4.4 Archaebacteria

• Archaebacteria are a type of bacteria that are adapted to extreme environments.

• They are single-celled organisms that lack a nucleus and other organelles.

• They are found in extreme environments such as hot springs, deep sea vents, and highly salty or acidic environments.

• They have a unique cell wall structure that is resistant to extreme temperatures and pressures.

• They are able to survive in these extreme environments by using metabolic processes that are different from other bacteria.

• Some species of archaebacteria can even produce their own food through photosynthesis.

• They have also developed specialized proteins that allow them to survive in extreme conditions.

4.5 Antarctic fish

• Antarctic fish have evolved to survive in the extreme cold temperatures of the Antarctic waters. 

• They have antifreeze proteins in their blood to prevent their cells from freezing. 

• They have thick layers of fat to help insulate them from the cold. 

• They have evolved to swim quickly to conserve energy and reduce the amount of time spent in the cold water. 

• Many Antarctic fish have evolved to live in the dark, deep waters of the Antarctic. 

• They have developed large eyes to help them see in the dark. 

• They have evolved to be more streamlined and have larger fins to help them swim faster. 

• They have also evolved to be able to survive on a limited food supply.

4.6 Seals 

• Seals are semi-aquatic mammals that live in the ocean.

• Seals have a streamlined body shape and webbed feet to help them swim.

• Seals have fur or blubber to keep them warm in the cold water.

• Seals can hold their breath for a long time and dive deep underwater to find food.

• Seals have adapted to their environment by developing strong swimming skills and thick fur to keep them warm.

4.7 Biochemical Adaptations 

1. Enzyme Activity: Many biochemical adaptations involve the regulation of enzyme activity, which can be altered to help an organism survive in a particular environment.

2. Metabolism: Metabolic pathways can be altered to allow an organism to better utilize available resources or to cope with changing environmental conditions.

3. Membrane Structure: Changes in the structure of a cell membrane can allow an organism to better survive in a particular environment.

4. Hormone Production: Hormones can be produced to help an organism respond to environmental changes.

5. Genetic Variations: Genetic variations can lead to biochemical adaptations that help an organism survive in a particular environment.

4.8 Behavioural Adaptations (Desert Lizard)

1. Temperature Regulation: Desert lizards are able to regulate their body temperature by changing their behavior. For example, they can move to cooler areas during the day and bask in the sun to warm up in the morning.

2. Camouflage: Desert lizards have evolved to blend in with their environment. For example, some species have adapted to match the color of the sand and rocks around them.

3. Burrowing: Desert lizards are also able to burrow into the sand to escape from predators and regulate their body temperature.

4. Nocturnal Activity: Many desert lizards are nocturnal, meaning they are active at night and sleep during the day. This helps them avoid the scorching daytime temperatures.

5.Population 

5.1 Population Attributes

• Population size: The total number of people in the population.

• Age distribution: The age range and breakdown of people within the population.

• Gender distribution: The ratio of males to females in the population.

• Ethnic composition: The racial and ethnic makeup of the population.

• Education level: The average educational attainment of the population.

• Employment status: The percentage of people in the population who are employed.

• Income level: The average income of the population.

• Geographic distribution: The geographic areas in which the population is located.

5.2 Population Density

Population density is a measure of how many people live in a given area. It is usually expressed as the number of people per square kilometer. It is an important indicator of a country's population and can be used to compare population densities between different countries or regions. 

Key Points: 

- Measure of how many people live in a given area 

- Usually expressed as number of people per square kilometer

- Important indicator of a country’s population 

- Can be used to compare population densities between different countries or regions

5.3 Population Growth

Population growth is the increase in the number of people living in a particular area. It can be measured by the number of births, deaths, and migration of people into and out of an area. 

Key Points:

- Population growth is measured by the number of births, deaths, and migration of people into and out of an area. 

- Population growth can be either positive (increase in population size) or negative (decrease in population size). 

- Population growth can be influenced by a variety of factors, such as fertility rates, mortality rates, migration patterns, and economic and environmental conditions. 

- Population growth can have both positive and negative impacts on an area, such as providing economic opportunities or straining resources.

5.4 Growth Models

1. Logistic Growth Model: This model describes population growth that increases rapidly at first, but eventually slows down and levels off at a maximum population size. 

2. Exponential Growth Model: This model describes population growth that increases at a constant rate over time, resulting in a J-shaped curve.

3. Linear Growth Model: This model describes population growth that increases at a steady, linear rate over time, resulting in a straight line.

4. Polynomial Growth Model: This model describes population growth that increases at a non-linear rate over time, resulting in an S-shaped curve.

6. LIFE HISTORY VARIATION

LIFE HISTORY VARIATION refers to the differences in the way organisms and populations develop, reproduce, and die. It is a key factor in determining the success of a species in its environment. 

Key Points: 

-Life history variation is the differences in the way organisms and populations develop, reproduce, and die. 

-It is a key factor in determining the success of a species in its environment. 

-The variation in life histories can affect the size and structure of populations, their ability to cope with environmental changes, and their evolutionary potential. 

-Life history variation can be caused by a variety of factors, including genetic variation, environmental conditions, and competition between species. 

-Studying life history variation can provide insights into the ecology and evolution of species, and can help inform conservation efforts.

7. POPULATION INTERACTIONS

• Competition: Organisms in the same population compete for resources such as food, water, and space. 

• Predation: Organisms in the population may prey on one another, with one organism consuming another. 

• Mutualism: Organisms may form mutually beneficial relationships, such as when one organism provides protection to another in exchange for food. 

• Commensalism: One organism may benefit from another without harming it. 

• Parasitism: One organism may live off of another, often causing harm to the host organism. 

• Dispersal: Organisms may disperse to new habitats, allowing for the spread of genes and species.

7.1 Predation

• Predation is a type of interaction between two organisms, where one organism (the predator) captures and feeds on the other organism (the prey).

• Examples of predators include lions, hawks, and wolves; examples of prey include zebras, rabbits, and fish.

• Predators use a variety of strategies to capture their prey, such as stalking, chasing, ambushing, and trapping.

• Predation can have a significant impact on the populations of both predators and prey.

• For prey, predation can reduce population size, alter behavior, and even drive species to extinction.

• For predators, predation can provide a reliable food source and lead to increased population size.

• Predation is an important part of the food web, as it helps to maintain balance in ecosystems by controlling the population sizes of different species.

7.2 Competition

Competition among organisms for resources is a fundamental process in ecology. It occurs when two or more organisms require the same limited resource, such as food, water, or living space. Competition can occur between members of the same species (intraspecific competition) or between members of different species (interspecific competition). 

Examples of Competition: 

1. Intraspecific Competition: This type of competition occurs between members of the same species. An example of this would be two lions competing for the same food source.

2. Interspecific Competition: This type of competition occurs between members of different species. An example of this would be a lion and a cheetah competing for the same food source. 

3. Predation: This type of competition occurs when one organism preys upon another for food. An example of this would be a lion preying upon a gazelle for food. 

4. Resource Partitioning: This type of competition occurs when two or more species use different parts of the same resource. An example of this would be two species of birds that feed on different parts of the same tree. 

5. Parasitism: This type of competition occurs when one organism lives on or in another organism and harms it in the process. An example of this would be a tick living on a deer and taking its blood for sustenance.

7.3 Parasitism

Parasitism is a relationship between two organisms, where one organism (the parasite) lives off of another organism (the host) for survival. The parasite usually benefits from the relationship, while the host is harmed. Examples of parasites include fleas, ticks, tapeworms, and lice. These organisms feed off the host's blood, skin, or internal organs. Other parasites, like fungi, can feed off of the host's nutrients. Parasitism is common in the animal kingdom, but can also be found in plants.

7.4 Commensalism

Commensalism is a type of relationship between two organisms, where one organism benefits while the other is neither harmed nor benefited. Examples of commensalism include barnacles on whales, oxpeckers on zebras, and clownfish living in anemones.

Key Points:

• Commensalism is a type of relationship between two organisms.

• One organism benefits while the other is neither harmed nor benefited.

• Examples of commensalism include barnacles on whales, oxpeckers on zebras, and clownfish living in anemones.

7.5 Mutualism

Mutualism is a type of symbiotic relationship between two different species of organisms where both species benefit from the association. This type of relationship is found in many different types of organisms, including plants, animals, fungi, and bacteria. 

Examples of Mutualism: 

1. The relationship between bees and flowers: Bees carry pollen from one flower to another, enabling the flowers to reproduce. In return, the flowers provide the bees with nectar and a place to rest. 

2. The relationship between certain species of ants and plants: The ants protect the plants from predators and help the plants disperse their seeds, while the plants provide the ants with food and shelter. 

3. The relationship between certain species of fungi and plants: The fungi provide the plants with essential nutrients and help them absorb water, while the plants provide the fungi with food and a place to grow. 

4. The relationship between certain species of bacteria and humans: The bacteria help the human body break down food, while the human body provides the bacteria with a place to live.

8. SYNOPSIS

A population is a group of organisms of the same species that live in the same area. Examples of populations include a group of deer in a forest, a school of fish in a lake, or a colony of ants in a meadow. 

In short, the population of an organism is the number of individuals of that species living in a particular area. Each population has its own unique characteristics, such as size, density, and distribution. Populations can be studied to better understand the behavior of the species and its interactions with the environment.

Organisms Population:

Organisms population is the total number of individuals of the same species living in a given area or habitat at a certain time. It includes both living and dead organisms.

• Organisms population is the total number of individuals of the same species living in a given area or habitat. 

• It includes both living and dead organisms. 

• It is important to study the population of organisms in order to understand the dynamics of a particular species. 

• It is also important to understand the impacts of human activities on the population of organisms, such as over-harvesting, habitat destruction, and pollution. 

• Understanding the population of organisms can help us to conserve and protect their habitats and ensure the sustainability of our ecosystems.