Unit 1: INTERCONNECTEDNESS OF LIFE

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.

The Big 8 - 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

Can you think of a characteristic that living things and non-living things have in common?

1. Living Things are Made up of Cells Cell- basic unit of all forms of life Depending on their general structure, cells are grouped into 2 separate categories: Prokaryotic Eukaryotic

1. LIVING THINGS ARE MADE UP OF CELLS (CONT) Major Differences Between Prokaryotic and Eukaryotic CELLS: Prokaryotic Eukaryotic Have no nucleus Have a nucleus Do NOT have membrane bound organelles Have membrane bound organelles Smaller Larger Example: Bacteria Examples: animals, plants, fungi, protists

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)

1. LIVING THINGS ARE MADE UP OF CELLS (CONT) Cellular Specialization takes place in multicellular organisms. Different types of cells perform different functions as parts of different tissues and organs.

2. Living Things are based on a Universal Genetic Code What is the genetic code of all organisms? What does it do? Why is it an important necessary part of every cell? Examples of traits: Physical features like eye color, face shape, etc. Behavioral features like personality, etc. Physiological processes like digestion, making cellular energy, etc.

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.

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?

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

3. LIVING THINGS REPRODUCE (CONT) Examples: Asexual Sexual Typically prokaryotic cells (bacteria) Less common but possible in eukaryotic 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. Some organisms can undergo both asexual and sexual reproduction.

3. LIVING THINGS REPRODUCE (CONT)

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

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

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.

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

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

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

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.

7. LIVING THINGS,TAKEN AS A GROUP, EVOLVE (CONT) Organisms cannot choose or change their characteristics because they want to or need to. It is by natural selection that traits are “selected for” (remain in the population) or eliminated. The environment dictates which traits will be selected for and which ones will be selected against. Successful traits that become established in a population of organisms are called adaptations.  

7. LIVING THINGS, TAKEN AS A GROUP, EVOLVE (CONT) As one adaptation follows another, eventually the species may undergo subtle or even drastic changes. Over time, groups of organisms can become different enough from one another that they are considered new species. What will happen to the population of these beetles over time?

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)?

8. LIVING THINGS OBTAIN AND USE MATERIALS & ENERGY Materials and energy move between the living (biotic) and nonliving (abiotic) parts of the ecosystem Materials (atoms, molecules) must be recycled but energy is NOT – therefore a constant supply of energy must enter every ecosystem From where does energy enter an ecosystem?

8. LIVING THINGS OBTAIN AND USE MATERIALS & ENERGY (CONT) Organisms must be able to Produce or obtain nutrients Convert the nutrients into a usable form of chemical energy called ATP Use these forms of energy to power their life processes

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 its own food from inorganic compounds Ex: All Plants, bacteria

There are 2 different types of autotrophs: 8. LIVING THINGS OBTAIN AND USE MATERIALS & ENERGY (CONT) There are 2 different types of autotrophs: Using light energy to convert CO2 and water into food (carbohydrates like glucose) Converting chemicals into food (carbohydrates like glucose)

8. LIVING THINGS OBTAIN AND USE MATERIALS & ENERGY (CONT) Photosynthesis can be summarized by the following equation 6 CO2 + 6H2O  C6H12O6 + 6 O2 What is the purpose of photosynthesis?

8. LIVING THINGS OBTAIN AND USE MATERIALS & ENERGY (CONT) The food is then used to make cellular energy (ATP- energy that cells can use to power their processes). 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: C6H12O6 + 6 O2  6 CO2 + 6 H2O + ATP What is the purpose of cellular respiration? IMPORTANT: All organisms undergo cellular respiration!

8. LIVING THINGS OBTAIN AND USE MATERIALS & ENERGY (CONT)

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. Photosynthesis is an energy-storing reaction; cellular respiration is an energy-releasing reaction.

8. LIVING THINGS OBTAIN AND USE MATERIALS & ENERGY (CONT) Chemical Reactions such as photosynthesis and cellular respiration are an essential part of life. In addition to those 2, there are many other chemical reactions that take place in every living thing. The combination of all of your chemical reactions is called your metabolism When metabolism stops…

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).

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

When species have characteristics in common they will be grouped into a common larger group, the Genus. Linnaeus placed organisms into larger more general groups based on characteristics. Linnaeus used the technique of starting with the general and moving to the more specific until he “zeroed in” on a particular species.

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

Bactrian camel and Dromedary

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

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

The science of classification has been undergoing a great deal of change Original scheme proposed back in the 1800s by Carolus Linnaeus included only 7 classification levels KPCOFGS Currently an additional grouping – domain – is becoming more widely accepted as a level above (more general) Kingdom. DNA has helped to continue to revise/reinforce the classification groupings being used today.

Domain 1. ____________ 2. ______________ 3._______________________ Prokaryotes Eukaryotes Domain 1. ____________ 2. ______________ 3._______________________        Kingdom  Phylum Arthropoda and chordata Etc. Arthropoda Chordata

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

We can’t live forever! Over time there is damage to DNA and cells Wear out, despite constant maintenance and repair throughout the organism’s life time Cannot always maintain homeostasis in all environmental conditions If an organism cannot continue its metabolism and maintain homeostasis, its life will cease. Earth has a limited supply of resources When organisms die materials in cells are recycled back into the environment for use by new generations of living things

Decomposers are essential to the recycling of materials between the living and non-living portions of every ecosystem.

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. Therefore, they are considered nonliving. 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

Influenza