1. Biology is the science that studies life and living organisms. It examines the cell, the basic unit of life, as well as levels of organization above the cell including tissues, organs, organ systems, organisms, populations, communities, and ecosystems.
2. All living things share two main characteristics - they require energy and contain DNA. Energy is required for functions like growth, development, reproduction, and homeostasis. DNA contains instructions that pass from parents to offspring and allow for inheritance, development, and growth.
3. The main levels of biological organization are the cell, tissue, organ, organ system, organism, population, community, and ecosystem. Ecosystems are controlled by energy flow and nutrient cycling between organisms
3. 3
Scientists use a systematic approach to gain understanding of the natural world.
- Observation
- Hypothesis formation
- Prediction
- Experimentation
- Conclusion
The Nature of Science: The Scientific Process
A hypothesis is a possible explanation for an observation
A hypothesis
- must be tested to determine its validity
- is often tested in many different ways
- allows for predictions to be made
5. LIFE
Life is an outcome of ancient events by which non living matter atoms and molecules became
assembled into first living cell.
Energy from
sun
Atoms Molecules
Membrane bound cell
Properties of life emerge at the level of cells
6. Living organisms:
The individual living thing is called an organism.
All living things are made up of cells.
Difference between a living and non living thing emerge
at molecular level by a special molecule called DNA
ex: bacterium, plant, fungus, or animal.
7. Characteristics of Living Organism
ALL LIVING ORGANISMS ARE MADE UP OF CELLS:
The cell is the smallest or basic unit of life; that can grow
survive and reproduce.
They form the structural and functional unit of an
organism.
Organisms can be single celled or multi cellular.
All cells arise from pre existing cells.
8. Characteristics of Living Organism
ALL LIVING ORGANISMS HAVE DNA IN CELLS:
De oxy ribonucleic acid:
Are signature molecules of a cell.
Contains information on growth, reproduction,
hereditary and development.
Flow of information is from DNA to RNA and protein.
9. FUNCTIONS – DNA TRANSFER
Is transmission of DNA from parent to offspring
Acquistion of traits (characters by transfer of DNA from
parent to offspring .
(ex: young ones resembling parent)
a. Inheritence:
10. FUNCTIONS – DNA TRANSFER
b. Reproduction
Is method by which an organism produce
off springs.
.
11. FUNCTIONS – DNA TRANSFER
c. Development
Transformation of fertlized egg into multi cellular organism
with cells, tissues and organs specialized for certain task.
DNA has instructions for development.
An individual undergoes many changes in life cycle
known as developmental changes.
d. Growth
Increase in size and weight.
12. Characteristics of Living Organism
ALL LIVING ORGANISMS REQUIRE ENERGY:
Energy is the capacity to do work.
Sunlight is the primary source of energy.
ATP (Adenosine tri phosphate) is the main energy carrier molecule of a cell.
13. PHOTOSYNTHESIS:
Process of trapping energy from sun and its
conversion to chemical energy (ATP) followed by
synthesis of sugars.
AUTOTROPH: Greek word.
Autos =self; troph = feeder.
Organism that makes its own food with the help of
sunlight as its energy source.
14. Inorganic salts (nutrients)
ENERGY TRANSFERS
SUN PRODUCER CONSUMER SECONDARY CONSUMER
DECOMPOSITION
Herbivores-
Animals that eat plants
Energy
Flow starts
from sun
Autotroph trap
Energy from sun
and store
Carnivores-
feed on other animals.
Death and excretion
ALL ENERGY THAT PLANT CAPTURED FROM SUN RETURNS BACK TO ENVIRONMENT
15. AUTOTROPHS OR PRODUCERS,OR
SELF FEEDERS
Organism that makes its own food by
photosynthesis.
All ecosystem run on energy trapped by
autotrophs, which convert energy from sun to
chemical energy so they are called primary
producers for the ecosystem.
Ex: Algae, plants
BASED ON NUTRITION
The must consume preformed organic nutrients that were
synthesized by autotrophs.
There are different kinds of heterotrophs classified according
to their diet.
Ex: animals, decomposers most fungi, many bacteria
CONSUMERS DECOMPOSERS
HETEROTROPHS
16. 1. Herbivores- plant eating animals.eg. Insects, cow.
2. Carnivores - eat flesh, feed on other animals.
Eg. Hawks feed on birds.
3. DECOMPOSERS: Break down dead organic waste of all
organisms into simple substances which is then taken up by producers.
Very valuable because they release inorganic nutrients which
can later be used by plants.
Ex: thousand species of bacteria, fungi, protists
HERBIVORES
TYPES OF HETEROTROPHS OR CONSUMERS
Carnivore can be a
secondary or tertiary consumer.
DECOMPOSERS
17. ENERGY AND LIFE ORGANIZATION
Biological organization:
Nature shows levels of organization.
The characteristics of life emerge at the level
of single cell and extend through population,
communities, ecosystem and biosphere.
18. A population is group of freely interacting
and breeding individuals of the same species.
Populations of different species living and
interacting together in an area
COMMUNITY
Community with physical environment and
Includes both biotic and abiotic factors
Region in earth where life exist.
Smallest unit, having capacity to live, reproduce
CELL
TISSUE Organized group pf cells performing a
common function
Structural units, formed by tissues
Two or more organs interacting physically and
chemically for survival of organism
Individual made of often organized into
tissues, organs etc.
19. Population:
Organisms of same kind (same species) living in a
particular area.
Species or organism:
are individuals made up of different types of cells
Community:
All populations of all species occupying a specified area
Different species living in same area.
20. ECOSYSTEM:
A community that is interacting with its physical and
chemical environment.
It has input and output of energy and materials.
ECOSYSTEMS =All the abiotic + biotic factors in a given area
Ex: Forest, desert, ocean, coral reef etc.
BIOSPHERE:
Total area of earth including earths crust, its atmosphere,
water, where organisms are found.
21. Characteristics of Living Organism
ALL LIVING ORGANISMS ENGAGE IN METABOLISM: Every cell obtain and convert energy
from its surroundings; use energy to maintain itself ,grow and reproduce. This capacity is
known as METABOLISM.
Food eaten is converted to energy to do work. This process of converting food to energy rich molecules
as an example of metabolism
22. METABOLISM
CATABOLISM ANABOLISM
Process of breaking up.
Destructive process.
Complex substances are broken
to simple one.
Energy compound is broken
Energy is released.
Ex. Respiration
Glucose----CO2 +H2O +energy
Process of building up.
Constructive process.
Complex substances are built
from simple one.
Energy compound is formed
Energy is synthesized.
Ex. Photosynthesis
Sun + CO2 +H2O = glucose
+energy
23. Characteristics of Living Organism
ALL LIVING ORGANISMS SENSE AND MAKE CONTROLLED RESPONSES TO EXTERNAL AND
INTERNAL CONDITIONS (HOMEOSTASIS):
INTERNAL CONDITIONS
Homeostasis is a state in which the internal environment is
being
maintained within tolerable limits.
Or
Ability of an organism to control their internal conditions
Or
The maintenance of the internal environment of an organism at
a steady state
While running heart beat increases
Because their should be enough
blood to supply tissues.
24. Homeostasis : EXTERNAL CONDITIONS
Person draws his hand away from hot surface. This is sensation and response.
Stimuli: Specific form of energy (light, heat etc)
Sensation: Ability to receive stimulus.
Receptor: cell or organ receiving stimulus.
Effector: organ cell responding to a stimuli.
25. 1.Cells are the structural and functional unit of organisms.
• Cells arise from pre existing cells.
a. Cells are the smallest, basic unit of life that can live independently, survive, grow and reproduce.
Summary - Unity of life
2. All cells have DNA :
a. which has instructions for inheritance, development and growth.
3. All living organisms require energy which they get from surroundings.
a. Sunlight is the main source of energy
b. ATP is the main energy carrier molecule of a cell.
4. All living organisms engage in metabolism
a. Which involves both anabolism and catabolism.
5.All living organisms adapt and respond to internal and external environment :
a. Maintain a steady state in response to internal environment by homeostasis.
b. Receives external stimulus and responds.
ALL THESE ARE SHARED CHRACTERS SHOWING UNITY OF LIFE
26. Chapter 1 :Concepts in Biology [P. 3-7, Figs 1.2 & 1.3]
What is Biology? page 3
What are the main Characteristics of living beings? List
the 2 main concepts of life. (Energy and DNA) pages
6- 7
What are the main differences among inheritance,
reproduction and development - page 7
The relation of energy to sensation and response and
homeostasis?
what is the role of ATP (energy carrier) page 6-7
List the main Levels of Biological Organization (beginning
from The cell) pages 4-5, Fig 1.2
What are the two main principles controlling any
ecosystem ? (Fig. 1.3 page 6)
What are meant by Autotrophs (Producers) -
Heterotrophs (consumers & decomposers) ? Fig. 1.3,
page 6
31. DNA HAS TWO QUALITIES
IT HELPS OFFSPRING TO LOOK LIKE PARENT.
YET
IT ALLOWS VARIATIONS TO OCCUR IN TRAITS.
32. Variations in trait or characters because of mutations
Heritable change in molecular structure of DNA.
Mutations in a gene's DNA sequence can alter the amino acid sequence of
the protein encoded by the gene.
MUTATION
MUTATION
LETHAL MUTATION
Harmful.
Change in even a single gene can
cause death.
Ex: Cancers
BENEFICIAL MUTATION
Not harmful
Change in DNA gives survival
advantage to organism.
Ex: Adaptive traits
33. Adaptive trait
Form of trait that gives the individual an advantage in
terms of survival and reproduction under a given set of
environmental conditions.
The Pepper Moth: What was observed
Year 1850 in England the moth were light colored.
Because of soot from industry ,all tree barks were coated with
soot. The light colored moth was easily seen by birds which ate
them so they developed more melanin and became dark
