1. Unit 1: Chemical Basis of Life

2. Unit 1A: Characteristics of Living Things
Biology is the scientific study of living things
Another word for a living thing is an organism.
Although the many types of organisms may appear to be different from one another, they all share common characteristics.

3. Part A- 8 Important Characteristics of Living Things:
Are made up of cells
Are based on a universal genetic code
Reproduce
Grow and develop
Respond to their environment
Maintain a stable internal environment
Taken as a group, evolve
Obtain and use materials and energy

4. Can you think of a characteristic that living things and non-living things have in common?
They are made up of ATOMS & MOLECULES

5. 1. Living Things are Made up of Cells
Cell- basic unit of all forms of life

6. 1. LIVING THINGS ARE MADE UP OF CELLS (CONT)
Unicellular
Multicellular
Made of only 1 cell
Must accomplish all life activities within one cell
Made up of more than 1 cell
Cells must work together to accomplish the organism’s life processes
Clown Fish (Euk)
Bacteria (prok)
Euglena (Euk)

7. 2. Living Things are based on a Universal Genetic Code
What is the genetic code of all organisms?
DNA (deoxyribonucleic acid)
What does it do? Why is it an important necessary part of every cell?
DNA is the genetic material of the cell which contains codes for the building of proteins.
Proteins contribute to our traits!

8. 2. Living Things are based on a Universal Genetic Code (cont)
A segment of DNA that codes for a specific protein is called a gene
The reason different cells in the same organism can have a different structure and function even though they all have the same DNA (genes) is because different genes are being used in these different cells. A specific cell will have certain genes turned on while other genes are turned off.

9. 3. LIVING THINGS REPRODUCE
The process of reproduction ensures that DNA is passed from parent(s) to offspring
Is reproduction necessary for the survival for the individual or the species?
Species!

10. Two Types of Reproduction
3. LIVING THINGS REPRODUCE (CONT)
Two Types of Reproduction
Asexual
Sexual
Involving a single parent cell
Offspring are genetically identical to the parent
Suitable for a stable environment
Involves joining 2 parent cells
Offspring have variations compared to parents and other offspring
Suitable for a changing environment

11. 3. LIVING THINGS REPRODUCE (CONT)
Examples:
Asexual
Sexual
Typically bacteria (unicellular)
Less common but possible in multicellular organisms.
Typical method for animals, plants, some fungi and protists.
Either method of reproduction has the potential to be very successful - depending on the species and its environment.

12. 3. LIVING THINGS REPRODUCE (CONT)

13. 4. Living things grow and develop
Both growth and development take place as an organism matures.
How would you differentiate between these 2 processes?
Growth
Development
Getting Larger
Size
Height
Weight
Changing Features
Ex: Butterfly life cycle or Puberty

14. 5. Living Things Respond To Their Environment
Stimulus
A signal to which and organism responds
Response
A specific reaction to a stimulus

15. 5. Living Things Respond To Their Environment (cont)
Examples:
Directions: Label each of these examples - put an "S" by the stimulus and an "R" by the response:
a) When you touch something
hot you pull your hand away.
b) A blowfish becomes larger and
extends is spikes when it is
threatened by a predator.

16. 5. Living Things Respond To Their Environment (cont)
What other examples can you think of?
Stimulus
Response

17. 6. LIVING THINGS MAINTAIN A STABLE INTERNAL ENVIRONMENT
When organisms maintain relatively constant or stable internal conditions we call this homeostasis.
These conditions must be maintained within certain limits regardless of any internal or external changes.
Example: regulation of body temperature
When its cold humans ---
When its hot, we ----
We want to maintain our body temp around 98.6°F

18. 6. LIVING THINGS MAINTAIN A STABLE INTERNAL ENVIRONMENT (CONT)
Another Example of Homeostasis:
Blood pH should be around 7.4
Various molecules called buffers work to keep your blood at the correct pH
Diabetes, kidney failure, starvation

19. 7. LIVING THINGS,TAKEN AS A GROUP, EVOLVE
Evolution: Change of organisms over time
Natural selection: the process by which organisms that have traits that make them better able to survive in their environment will be more successful at reproducing and therefore pass these traits on to future generations.

20. 7. LIVING THINGS, TAKEN AS A GROUP, EVOLVE (CONT)
What will happen to the population of these beetles over time? Why?

21. 7. LIVING THINGS, TAKEN AS A GROUP, EVOLVE (CONT)
How do the new traits (variations) that are “selected for” by natural selection arise in organisms? (Where do these new traits or variations come from)?
Changes in the DNA (mutations) during reproduction can lead to adaptations in the offspring.

22. 8. LIVING THINGS OBTAIN AND USE MATERIALS & ENERGY
Materials and energy move between the living (biotic) and nonliving (abiotic) parts of the ecosystem

23. 8. LIVING THINGS OBTAIN AND USE MATERIALS & ENERGY (CONT)
Organisms must be able to
Produce or obtain nutrients (like food and water)
Convert the nutrients into a usable form of chemical energy called ATP
Use these forms of energy to power their life processes
All living things fit into one of two categories based on how they produce or obtain nutrients.

24. 8. LIVING THINGS OBTAIN AND USE MATERIALS & ENERGY (CONT)
Heterotrophs (consumers)
Autotrophs (producers)
Obtains food by consuming other living things
Ex: Animals, fungi, bacteria
Capture energy from sunlight or chemicals and use it to produce their own food
Ex: All Plants, bacteria

25. 8. LIVING THINGS OBTAIN AND USE MATERIALS & ENERGY (CONT)
Photosynthesis is the process used by autotrophs to convert carbon dioxide and water into carbohydrates using energy from the sun.
What is the purpose of photosynthesis?
To make food molecules

26. 8. LIVING THINGS OBTAIN AND USE MATERIALS & ENERGY (CONT)
The food is then used to build the structure of the organism and make cellular energy (ATP- energy that cells can use to power their processes).

27. 8. LIVING THINGS OBTAIN AND USE MATERIALS & ENERGY (CONT)
Cellular respiration
Process that releases energy by breaking down glucose and other food molecules in the presence of oxygen.
Cellular Respiration can be summarized by the following chemical equation:
What is the purpose of cellular respiration?
To turn food molecules into ATP
IMPORTANT: All organisms undergo cellular respiration!

28. 8. LIVING THINGS OBTAIN AND USE MATERIALS & ENERGY (CONT)
Put the words “photosynthesis” and “cellular Respiration” in the correct blank on the diagram.

29. How are photosynthesis and cellular respiration related????
8. LIVING THINGS OBTAIN AND USE MATERIALS & ENERGY (CONT)
How are photosynthesis and cellular respiration related????
The products of one reaction become the reactants of the other.
In other words, each reaction makes what the other reaction needs.

30. 8. LIVING THINGS OBTAIN AND USE MATERIALS & ENERGY (CONT)
The combination of all of your chemical reactions is called your metabolism
When metabolism stops, An organism CANNOT perform life functions  DEATH 

31. ONE LAST FEATURE OF LIVING THINGS
All living things must die Life Span- How long an organism lives

33. We can’t live forever! Over time there is damage to DNA and cells
Cannot always maintain homeostasis in all environmental conditions
Earth has a limited supply of resources when organisms die the materials in their cells are recycled back into the environment for use by new generations of living things

34. Part B- Classification of Organisms
Taxonomy- The Science of Classification
Involves grouping and naming organisms
Carolus Linnaeus-
Binomial nomenclature- classification system in which each species is assigned a two-part scientific name.
The first word is called the Genus.
The second word is called the species (often a descriptive word, such as a color or physical patterning).

35. Species:
A group of similar organisms that can breed and produce fertile offspring
Common Name
Scientific Name
Daffodil
Narcissus pseudonarcissus
Human
Homo sapiens
Bullfrog
Rana catesbiana
Green frog
Rana clamitans
Leopard frog
Rana pipiens

36. Linnaeus placed organisms into larger more general groups based on characteristics.

37. Linnaean Taxonomic Categories
The 7 major categories in classifying organisms, from most general to least general (most specific) are:
Kingdom
Phylum
Class
Order
Family
Genus
Species
K P C O F G S

38. Grizzly and Black Bear
Ursus americanus

39. Human
Wolf
Turtle
Mosquito
kingdom
Animal
phylum
Chordata
Arthropoda
class
Mammalia
Reptilia
Insecta
order
Primates
Carnivora
Chelonia
Diptera
family
Hominidae
Canidae
Emydidae
Culicidae
genus
Homo
Canis
Terrapene
Theobaldia
species
sapiens
lupus
carolina
anulata
1.Of the following, the broadest (most general) classification category is
A. class B. phylum C. genus D. order
2.Two organisms classified in the same class must be in the same
A. phylum B. family C. order D. genus

40. Human
Wolf
Turtle
Mosquito
kingdom
Animal
phylum
Chordata
Arthropoda
class
Mammalia
Reptilia
Insecta
order
Primates
Carnivora
Chelonia
Diptera
family
Hominidae
Canidae
Emydidae
Culicidae
genus
Homo
Canis
Terrapene
Theobaldia
species
sapiens
lupus
carolina
anulata
3.Two organisms classified in the same class could be in the same
A. genus B. order C. family D. all of these
4.Of the following, Rana catesbiana is most closely related to
A. Rana pipiens B.Homo sapiens C.Xenopus laevis D. Felis domesticus
5.Of the following, the correct order from largest, most general group, to smallest, most specific group, is
A. species, genus, family, class, order C. class, order, family, genus, species
B. species, family, genus, class, order D. class, genus, order, family, species

41. 6 Kingdoms of Living Things

42. VIRUSES: ALIVE or NOT?
There is some debate over whether viruses are living or nonliving. Most agree that they are nonliving. Why?
They are unable to INDEPENDENTLY carry out all life processes
They are particles made of DNA & proteins that can replicate only by infecting living cells.
Do not belong to any kingdom and don't contain any cells.
In addition, viruses do not have the characteristics of life. It cannot respond to a stimulus. It cannot grow and develop. It cannot adapt to the environment. The only way to reproduce is to do it inside a host cell and cannot independently reproduce

43. Explain why someone would think viruses are considered living things based on the 8 characteristics of life.
Influenza