2-1 Characteristics of Living Things

2-1 Characteristics of Living Things

1. Made of one or more units called cells1. Made of one or more units called cells

2. Reproduce2. Reproduce

3. Grow and Develop3. Grow and Develop

4. Obtain and use energy4. Obtain and use energy

5. Respond to their environment5. Respond to their environment

#1 Living things are made up of cells

#1 Living things are made up of cells

• Cell – small self contained unit

• Can perform all the functions of life

• Cell – small self contained unit

• Can perform all the functions of life

• Unicellular – organism made of one cell

• Multicellular – organism made of many cells

• Unicellular – organism made of one cell

• Multicellular – organism made of many cells

• Cells are only found in living material or material that was once alive

• Cells are only found in living material or material that was once alive

#2 Living things Reproduce#2 Living things Reproduce

• Produce organisms like themselves• Produce organisms like themselves

• Sexual reproduction – 2 cells formed from different individuals unite to form an organism

• Sexual reproduction – 2 cells formed from different individuals unite to form an organism

• Asexual Reproduction – single • Asexual Reproduction – single

#3 – Living things grow and develop

#3 – Living things grow and develop

• Are capable of growth at one stage of their life cycle at least

• Development – cycle of growth

• Are capable of growth at one stage of their life cycle at least

• Development – cycle of growth

• Aging – comes at the end of development– Organism becomes less efficient at the

process of life

• Aging – comes at the end of development– Organism becomes less efficient at the

process of life

#4 – Living things obtain and use energy

#4 – Living things obtain and use energy

• Energy from their environment or surroundings

• Energy to grow, develop, and reproduce

• Energy from their environment or surroundings

• Energy to grow, develop, and reproduce

• Metabolism = Anabolism + Catabolism• Metabolism = Anabolism + Catabolism

• Anabolism – putting together or synthesizing complex substances from simpler substances

• Anabolism – putting together or synthesizing complex substances from simpler substances

• Plants – photosynthesis

• Animals – take in energy food

• Plants – photosynthesis

• Animals – take in energy food

• Catabolism – final breakdown of complex substances into simpler substances resulting in the release of energy

• Catabolism – final breakdown of complex substances into simpler substances resulting in the release of energy

#5 – Living Things respond to their environment

#5 – Living Things respond to their environment

• Slow – changes in metabolic processes

• Rapid – changes in behavior

• Slow – changes in metabolic processes

• Rapid – changes in behavior

• Stimulus – anything that causes an organism to react

• Irritability – the ability of living things to react to stimuli

• Stimulus – anything that causes an organism to react

• Irritability – the ability of living things to react to stimuli

• Living things respond to stimuli in a way that improves their chances for survival

• Living things respond to stimuli in a way that improves their chances for survival

HomeostasisHomeostasis

• Organisms ability to maintain constant or stable conditions that are necessary for life

• Process by which organisms respond to different stimuli

• Homeo – same

• Stasis – stopping/standing

• Organisms ability to maintain constant or stable conditions that are necessary for life

• Process by which organisms respond to different stimuli

• Homeo – same

• Stasis – stopping/standing

2-2 Biology: The Study of Life

2-2 Biology: The Study of Life

• Biology – the study of life

• Biologist – person who studies living things

• Biology – the study of life

• Biologist – person who studies living things

Branches of BiologyBranches of Biology

• Many divisions– Molecular biologist– Cell biologist– Zoologist (animals)– Botanist (plants)– Paleontologists– Ecologists– Global Ecologists

• Many divisions– Molecular biologist– Cell biologist– Zoologist (animals)– Botanist (plants)– Paleontologists– Ecologists– Global Ecologists

Questions at the ….Questions at the ….

• Molecular level

• Cellular level

• Multicellular level

• Population level

• Global level

• Molecular level

• Cellular level

• Multicellular level

• Population level

• Global level

Tools of a BiologistTools of a Biologist

• To study small organisms microscopes– Produces a larger image

• To study small organisms microscopes– Produces a larger image

Compound Light MicroscopeCompound Light Microscope

• Most common

• Can observe living organisms

• Light passes through the organism

• Two types of lenses

– Objectives – 2

– Ocular (eyepiece)

• Most common

• Can observe living organisms

• Light passes through the organism

• Two types of lenses

– Objectives – 2

– Ocular (eyepiece)

• Total Magnification =

• Ocular x Objective

• Total Magnification =

• Ocular x Objective

Limit of ResolutionLimit of Resolution

• Beyond this point objects become blurry and detail is lost – will always exist

• Increase magnification – more and more detail until you reach the limit of resolution

• Beyond this point objects become blurry and detail is lost – will always exist

• Increase magnification – more and more detail until you reach the limit of resolution

StainingStaining

• Colors some parts of the cell to make them clearly visible

• Colors some parts of the cell to make them clearly visible

Types of MicroscopesTypes of Microscopes

• Compound light microscope

• Electron microscope

• Compound light microscope

• Electron microscope

Electron MicroscopeElectron Microscope

Electron MicroscopeElectron Microscope

• Can see smaller things than the compound

• Uses electromagnets to bend electrons

• Two types – SEM and TEM

• Can see smaller things than the compound

• Uses electromagnets to bend electrons

• Two types – SEM and TEM

TEM (Transmission)TEM (Transmission)

• How it works – shine a beam of electrons at a sample and magnify the image onto a florescent screen (TV)

• How it works – shine a beam of electrons at a sample and magnify the image onto a florescent screen (TV)

SEM – ScanningSEM – Scanning

• How it works – beam of electrons scans back and forth across the surface of a specimen

• Electrons bounce off the specimen are picked up by detectors and a 3-D image is formed

• How it works – beam of electrons scans back and forth across the surface of a specimen

• Electrons bounce off the specimen are picked up by detectors and a 3-D image is formed

Limitations of Electron Microscopes

Limitations of Electron Microscopes

• Specimens must be in a vacuum (no air)

• Thin slices

• Stained, dried out or dead

• Specimens must be in a vacuum (no air)

• Thin slices

• Stained, dried out or dead

Laboratory Techniques of a Biologist

Laboratory Techniques of a Biologist

CentrifugationCentrifugation

• Cell fractionation – cells blended in a blender

• Broken bits spun 20,000x a minute

• Cell fractionation – cells blended in a blender

• Broken bits spun 20,000x a minute

• Heaviest parts sink

• Scientists remove the part they want

• Heaviest parts sink

• Scientists remove the part they want

MicromanipulationMicromanipulation

• Microdissection – can be used to remove cell parts

• Can be used to insert material in a living cell

• Microdissection – can be used to remove cell parts

• Can be used to insert material in a living cell

Cell CulturesCell Cultures

• Used to produce large numbers of cells

• Cell is grown in a dish with nutrients

• Overtime many cells develop

• Used to produce large numbers of cells

• Cell is grown in a dish with nutrients

• Overtime many cells develop

The EndThe End