INTERRELATIONSHIPS
SYMBIOSIS
 Interaction between two organisms of different species in which atleast one benefits is called symbiosis.
1.
Mutualism
 Both organisms benefit.
 Organisms provide each other with food and/or protection.
Examples:
 Ungulates (cow) and bacterias in their intestines
 Humans and horses
2.
Commensalism
 One organism benefits while the other is unaffected.
Examples:
 Clown fish and the sea anemone
3.
Parasitism
 One organism benefits, while the other is harmed.
 Host - the organism harmed
Examples:
 Kuto
 Linta
 Garapata
MORE INTERRELATIONSHIPS
4.
Predation
 Feeding of one organism on another.
 Predator - organisms that feed on the other organism
 Prey - organisms being eaten
Example:
 Cheetah and monkey
5.
Competition
 Two species use the same limited resources.
 Can happen to same species because they have common needs.
Example:
 Barnacles
6.
Ammensalism
 One species is hurt, but the other does not benefit.
Example:
 As wild pigs forage, they often disturb the upper layer of soil and many organisms may be taken
from their burrows and exposed to predation by the action of the pigs, although the harm that the
burrowers suffer does not improve the pig's situation at all.
 The Black Walnut Tree is an example of amensalism. It releases a chemical from its roots that
harms the plants around it.
 Another example of amensalism is the bread mold Penicillium, which secretes penicillan, a
chemical that kills bacteria.
7.
Protocooperation
 A mutually beneficial relationship that is not obligatory.
 Two species interact with each other beneficially; they have no need to interact with each other they
interact purely for the gain that they receive from doing this. It is not at all necessary for
protocooperation to occur; growth and survival is possible in the absence of the interaction.
Example:
 The Egyptian plover removes insect pests from the backs of buffalo, antelope, giraffes, rhinos, and
also leeches from the open mouths of crocodiles.
 The cattle egret in America as well does the same task of removing the unwanted insects and
parasites.
8.
Neutralism
 Both the populations are not affected by each others presence
Example:
 The tarantulas living in a desert and the cacti living in a desert.
BIOGEOCHEMICAL CYCLES
 As certain chemical elements cycle through an ecosystem, they interact with both living (bio) and nonliving
(geo-) components of the ecosystem. These elements are recycled within the system in what are known as
biogeochemical cycles.
 Unlike energy, materials (inorganic nutrients) flow in the ecosystem through a cyclic manner.
ENERGY vs MATERIALS (Nutrients)
ENERGY
MATERIALS (NUTRIENTS)
SOURCE: SUN
(supplied from outside)
SOURCE: PHYSICAL ENVIRONMENT
Flows through a NON-CYCLIC manner
Flows in a CYCLIC manner
 Materials are continuously recycled to obtain balance in the environment.
1.
Water Cycle (also known as the Hydrologic Cycle
 The continuous movement of water in the biosphere is called the Water Cycle.
 Solar energy evaporates water from the oceans, water in the soil, lakes, rivers, ponds, leaves of plants and
from bodies of living organisms. Water molecules are carried up to the atmosphere as water vapor and it
condenses and changes to water droplets and form clouds, and eventually fall to the earth’s surface again.
THE PROCESSES
Evaporation (transpiration-leaves of plants)
Condensation (cloud formation)
Precipitation (hail, snow, rain)
a. The water that falls on land is pulled back to the ocean by the force of gravity
b. Some of the water that falls on land penetrates through the soil until it reaches saturation
c. In the zone of saturation all crevices, cracks and pores of rocks are filled with water
d. The zone of saturation is called water table. Below this is the solid rocks which the water cannot penetrate
e. The deep ground water moving slowly also reaches the ocean, completing the cycle, and starts over again.
2.
Carbon Cycle
 The Carbon Cycle is a complex series of processes through which all of the carbon atoms in existence rotate.
The same carbon atoms in your body today have been used in countless other molecules since time began.
The wood burned just a few decades ago could have produced carbon dioxide which through photosynthesis
became part of a plant. When you eat that plant, the same carbon from the wood which was burnt can become
part of you.
 Solar energy evaporates water from the oceans, water in the soil, lakes, rivers, ponds, leaves of plants and
from bodies of living organisms. Water molecules are carried up to the atmosphere as water vapor and it
condenses and changes to water droplets and form clouds, and eventually fall to the earth’s surface again.
THE PROCESS
a. Plants, animals, and soil interact to make up the basic cycles of nature. In the carbon cycle, plants absorb
carbon dioxide from the atmosphere and use it, combined with water they get from the soil, to make the
substances they need for growth. The process of photosynthesis incorporates the carbon atoms from
carbon dioxide into sugars.
b. Animals eat the plants and use the carbon to build their own tissues. Other animals, such as the fox, eat the
rabbit and then use the carbon for their own needs. These animals return carbon dioxide into the air when
they breathe, and when they die, since the carbon is returned to the soil during decomposition. The carbon
atoms in soil may then be used in a new plant or small microorganisms.
c. Ultimately, the same carbon atom can move through many organisms and even end in the same place
where it began. Herein lies the fascination of the carbon cycle; the same atoms can be recycled for
millennia!
BIOMES


Large geographic regions containing distinctive plant and animal communities
The geographical distribution (and productivity) of the various biomes is controlled primarily by the
climatic variables precipitation and temperature.
1.
Tropical Rainforest
 Receives an incredible amount of rain.
 The tropical rainforest is a home to a great variety of animals.
Layers of a Tropical Rainforest
a. Forest Floor
b. Understory
c. Canopy
d. Emergent Layer
2.
Grassland
 Grasses thrive in places that are too dry for a forest to grow but too wet for a desert to develop.
 The tropical rainforest is a home to a great variety of animals
Types of Grasslands
a. Tropical Grassland - climate is hot all year round
b. Temperate Grassland - grasslands in places with hot summers and cold winters
3.
Desert
 The desert consists of shrub covered land where the plants are spatially quite dispersed.
 Climatically, deserts are influenced by descending air currents which limit the formation of precipitation.
4.
Temperate Forests
 Temperate forests grow in milder climates. The weather in a temperature climate changes with the seasons.
Forest trees help keep the temperatures mild.
5.
Temperate Deciduous
 Home of hardwood trees.
 This biome has been very extensively affected by human activity, and much of it has been converted into
agricultural fields or urban developments.
6.
Temperate Coniferous
 Trees in a coniferous forest are conifers (evergreen trees) which produce seeds in cones instead of flowers
7.
Tundra
 Vast polar plain between the Taiga and permanent ice surrounding the North pole.
Guide Questions:
What is transpiration?
Water vapor from plants. The release of water vapor from the tissues of plants.
Enumerate the layers of biological organization. Explain each layer.
a. Biosphere -> where an organism can live.
b. Biome -> a diverse collection of animals and plants depending on the climate and precipitation.
c. Ecosystem -> it is where biotic and abiotic factors interact.
d. Community -> made up of different populations interacting in one place.
e. Population -> group of the same species.
f. Organization
What is ecology?
Branch of Biology that studies the biotic and abiotic relationship in an ecosystem.
What is the difference between biotic and abiotic factors in an ecosystem?
Biotic factors are the living things and the abiotic factors are non-living things.
What is a food chain? What are food webs?
A food chain is the transfer of energy from the producers to the consumers.
Food webs are the connection of food chains.
What is a trophic level?
The levels where the energy is passed through from the producers to the rest of the consumers.
What are the parts of the Scientific Method?
a. Observation
b. Problem
c. Hypothesis
d. Experiment
e. Analysis
f. Conclusion
What is an independent factor? What is a dependent factor?
Independent factors change.
Dependent factors don’t change as they depend on the independent factors.
What is nitrogen fixation?
The process which nitrogen in the atmosphere is converted into ammonia.
What is denitrification?
The conversion of nitrates to nitrogen gas.
EVOLUTION


A change in a population of organisms over time...
A process which gradually selects the organisms that are better adapted to their environment to
continuously change life and make all organisms in our world the way they are today.
It is not a finished event wherein humans are the final product.

1. Thomas Malthus
⎻
⎻
1.
Wrote the Essay on the Principles of Population (1798)
“Population increase is limited by the availability of food through competition.”
Carl Von Linne (Carolus Linnaeus)
⎻
⎻
⎻
Published Systema Naturae (1753)
Classification of Organisms
“Animals with widely different forms and habits were often fundamentally similar in structure and
development.”
2. Jean Baptiste de Lamarck
⎻
⎻
Theory of Inheritance of Acquired Characteristics and Theory of Use and Disuse
 Use and disuse – Individuals lose characteristics they do not require (or use) and develop
characteristics that are useful.
 Inheritance of acquired traits/characteristics – Individuals inherit the traits of their ancestors.
His main points were:
i. evolution or change within a species is driven by an innate, inner striving toward greater perfection,
ii. use or disuse of various organs made them larger or smaller, accordingly, and
iii. these acquired traits could be inherited or passed on to offspring (inheritance of acquired traits).
3. Charles Darwin
⎻
⎻
⎻
Natural Selection
“Survival of the fittest”
published “On the Origin of Species” –Nov. 24, 1859
Natural Selection
 individuals, even siblings, in a population vary
 these variations can be passed to off springs
 (from Malthus) more offspring are produced than the environment can support competition for
resources and
 those individuals whose characteristics make them best suited to the environment live and reproduce and
have more offspring survival of the fittest.
I ADVISE TO READ THE BOOK FOR MORE NOTES ABOUT EVOLUTION 
TAXONOMY
There are 13 billion known species of organisms
This is only 5% of all organisms that ever lived!
New organisms are still being found and identified
Classification
• Classification is the arrangement of organisms into orderly groups based on their similarities
• Classification is also known as taxonomy
• Taxonomists are scientists that identify & name organisms
Benefits
 Accurately & uniformly names organisms
 Prevents misnomers such as starfish & jellyfish that aren't really fish
 Uses same language (Latin or some Greek) for all names
Early Taxonomists
1. 2000 years ago, Aristotle was the first taxonomist.
⎻ Aristotle divided organisms into plants & animals.
⎻ He subdivided them by their habitat ---land, sea, or air dwellers .
2. John Ray, a botanist, was the first to use Latin for naming
⎻ His names were very long descriptions telling everything about the plant
3. Carolus Linnaeus
⎻ 18th century taxonomist
⎻ Classified organisms by their structure
⎻ Developed naming system still used today
⎻ Called the “Father of Taxonomy”
⎻ Developed the modern system of naming known as binomial nomenclature
⎻ Two-word name (Genus & species)
Standardized Naming
 Binomial nomenclature used
 Genus species
 Latin or Greek
 Italicized in print
 Capitalize genus, but NOT species
 Underline when writing
Rules for Naming Organisms
i.
The International Code for Binomial Nomenclature contains the rules for naming organisms
ii.
All names must be approved by International Naming Congresses (International Zoological Congress)
iii.
This prevents duplicated names
In the taxonomy of Linnaeus there are three kingdoms, divided into classes, and they, in turn, into orders, genera
(singular: genus), and species (singular: species), with an additional rank lower than species.
THREE KINGDOMS
a.
Regnum Animale,
b. Regnum Vegetabile and
c.
Regnum Lapideum
Hierarchy – Taxonomic Groups
Domain

BROADEST TAXON
Kingdom
Phylum (Division – used for plants)
Class
Order
Family
Genus
Species

MOST SPECIFIC
Domains
• Broadest, most inclusive taxon
• Three domains
• Archaea and Eubacteria are unicellular prokaryotes (no nucleus or membrane-bound organelles)
• Eukarya are more complex and have a nucleus and membrane-bound organelles
UNICELLULAR PROKARYOTES
Archaea
 Probably the 1st cells to evolve
 Live in HARSH environments
 Found in:
⎻ Sewage Treatment Plants
⎻ Thermal or Volcanic Vents
⎻ Hot Springs or Geysers that are acidic
⎻ Very salty water (Dead Sea; Great Salt Lake)
Eubacteria
 Some may cause DISEASE
 Found in ALL HABITATS except harsh ones
 Important decomposers for environment
 Commercially important in making cottage cheese, yogurt, buttermilk, etc.
DOMAIN EUKARYA
Protista (protozoans, algae ..)
 Most are unicellular
 Some are multicellular
 Some are autotrophic, while others are heterotrophic
 Aquatic
Fungi (mushrooms, yeast ..)
 Multicellular, except yeast
 Absorptive heterotrophs (digest food outside their body & then absorb it)
 Cell walls made of chitin
Plantae (multicellular plants)
 Multicellular
 Autotrophic
 Absorb sunlight to make glucose – Photosynthesis
 Cell walls made of cellulose
Animalia (multicellular animals)
 Multicellular
 Ingestive heterotrophs (consume food & digest it inside their bodies)
 Feed on plants or animals
Taxons
• Most genera contain a number of similar species
• The genus Homo is an exception (only contains modern humans)
• Classification is based on evolutionary relationships
Basis for Modern Taxonomy
 Homologous structures (same structure, different function)
 Similar embryo development
 Molecular Similarity in DNA, RNA, or amino acid sequence of
Proteins
Cladogram
• Diagram showing how organisms are related based on shared, derived
characteristics such as feathers, hair, or scales
PRIMATE CLADOGRAM
Dichotomous Keying
• Used to identify organisms
• Characteristics given in pairs
• Read both characteristics and either go to another set of characteristics OR identify the organism
Examples
1a Tentacles present – Go to 2
1b Tentacles absent – Go to 3
2a Eight Tentacles – Octopus
2b More than 8 tentacles – 3
3a Tentacles hang down – go to 4
3b Tentacles upright–Sea Anemone
4a Balloon-shaped body–Jellyfish
4b Body NOT balloon-shaped - 5