Foundations of Life Unit 2

Biology is the science that studies living things. Bio- means life and –ology means study of.

People’s ideas about where some living things come from have changed over the centuries. People’s ideas about where some living things come from have changed over the centuries.

About 2300 years ago, the Greek philosopher Aristotle tried to explain his observation of the natural world through reasoning. About 2300 years ago, the Greek philosopher Aristotle tried to explain his observation of the natural world through reasoning.

As part of his observations, he thought he was observing life coming from non-living objects… As part of his observations, he thought he was observing life coming from non-living objects… Like dirt and water make fish and an old shirt and grain made mice. Like dirt and water make fish and an old shirt and grain made mice.

For centuries, people accepted that some life somehow “arose” from nonliving matter. For centuries, people accepted that some life somehow “arose” from nonliving matter. The idea that life could arise from nonliving things is called spontaneous generation. The idea that life could arise from nonliving things is called spontaneous generation.

About 400 years ago, some people began to challenge these ideas. About 400 years ago, some people began to challenge these ideas. They began to use experiments to answer the questions about life. They began to use experiments to answer the questions about life.

One such scientist was Francesco Redi (an Italian physician). One such scientist was Francesco Redi (an Italian physician). He set out to prove that meat left out didn’t produced maggots. He proposed that flies produced maggots. He set out to prove that meat left out didn’t produced maggots. He proposed that flies produced maggots.

Look at his experiment on page 9 in your textbook. Look at his experiment on page 9 in your textbook

Redi predicted that keeping flies away from the meat would prevent the appearance of maggots. Redi predicted that keeping flies away from the meat would prevent the appearance of maggots. Make a sketch in your notes of Redi’s experiment and results. Make a sketch in your notes of Redi’s experiment and results.

While Redi was working on his experiment, Anton van Leeuwenhoek discovered a world of tiny moving objects in rainwater, pond water and dust. While Redi was working on his experiment, Anton van Leeuwenhoek discovered a world of tiny moving objects in rainwater, pond water and dust. oo3A oo3A oo3A oo3A

Leeuwenhoek inferred these objects were alive and called them “animalcules” (tiny animals). Leeuwenhoek inferred these objects were alive and called them “animalcules” (tiny animals). For the next 200 years, scientists could not agree on whether the animalcules were alive or how they came to exist. For the next 200 years, scientists could not agree on whether the animalcules were alive or how they came to exist.

John Needham (an English scientist) didn’t agree with Redi and stated that spontaneous generation could occur under the right condition. John Needham (an English scientist) didn’t agree with Redi and stated that spontaneous generation could occur under the right condition.

Needham’s Experiment… let’s watch. Needham’s Experiment… let’s watch. kkNA kkNA kkNA kkNA

Take a minute to summarize Needham’s experiment, his conclusion and what mistake he made in this investigation. Take a minute to summarize Needham’s experiment, his conclusion and what mistake he made in this investigation.

An Italian scholar, Lazzaro Spallanzani read of Redi’s and Needham’s work. An Italian scholar, Lazzaro Spallanzani read of Redi’s and Needham’s work. He believed that Needham had not heated his samples enough to kill the animalcules. He believed that Needham had not heated his samples enough to kill the animalcules.

Spallanzani tried to improve on Needham’s experiment and to prove that nonliving things did not produce living things. Spallanzani tried to improve on Needham’s experiment and to prove that nonliving things did not produce living things. Look on page 11 to see his improvements to Needham’s experiment. Look on page 11 to see his improvements to Needham’s experiment.

What changes did Spallazani make to Needham’s experiment? What changes did Spallazani make to Needham’s experiment? Spallazani concluded that nonliving gravy did not produce living things. He said the microorganisms entered the jar through the air. Spallazani concluded that nonliving gravy did not produce living things. He said the microorganisms entered the jar through the air.

This experiment and Redi’s work supported the hypothesis that new organisms are produced only by existing organisms. This experiment and Redi’s work supported the hypothesis that new organisms are produced only by existing organisms.

Even as late as the 1800’s some scientists still believed in spontaneous generation. Even as late as the 1800’s some scientists still believed in spontaneous generation. In 1864, Louis Pasteur found a way to finally disprove spontaneous generation. In 1864, Louis Pasteur found a way to finally disprove spontaneous generation.

Look on page 12 to see Pasteur’s experiment. Look on page 12 to see Pasteur’s experiment. Sketch out his experiment and procedures. Sketch out his experiment and procedures.

Pasteur waited a year (still no microorganisms in his flask) before he broke it. Pasteur waited a year (still no microorganisms in his flask) before he broke it. In just one day, his broth was full of microorganisms. Finally, scientist believed that all living things came from other living things. In just one day, his broth was full of microorganisms. Finally, scientist believed that all living things came from other living things.

Let’s look at Redi’s, Spallazani’s and Pasteur’s experiments again. Let’s look at Redi’s, Spallazani’s and Pasteur’s experiments again

Living things all share certain characteristics. The Biology Song - YouTube

Characteristics of Living Things: 1) Living things are made up of cells. A cell is the smallest unit of an organism that can be considered alive.

2) Living things grow and develop. When an organism grows it gets larger by making more cells. Develop means to change shape by cell differentiation.

3) Living things reproduce. Living things produce new organisms by either sexual or asexual reproduction.

Sexual reproduction is the union of the sperm and egg. Sexual reproduction is the union of the sperm and egg. The advantage is genetic variation of the offspring. The advantage is genetic variation of the offspring.

Asexual reproduction is when one organism produces offspring on their own with the offspring being a clone of the parent. Asexual reproduction is when one organism produces offspring on their own with the offspring being a clone of the parent.

4) Living things obtain and use materials and energy. Organisms must take in energy to carry out all life functions. This energy is released through many chemical reactions in a process called metabolism.

5) Living things store information in genetic code written in a molecule of DNA. DNA not only has information about what an organism looks like but also instructions on carrying out life.

6) Living things maintain a stable internal environment through a process called homeostasis. Even if conditions outside an organism is changing, the organism must keep internal conditions balanced.

7) Living things respond to their environments. Organisms detect and respond to a stimulus.

8) Taken as a group, living things evolve. Over many generations, groups of organisms change over time.

Let’s review! The Characteristics of Living Things - YouTube

In order to meet all of the characteristics of life, there are several life processes that help with this. In order to meet all of the characteristics of life, there are several life processes that help with this.

Events that make life possible: 1) Nutrition: the use of nutrients by organism

2) Digestion: the process of breaking food down into a form the cells can use 2) Digestion: the process of breaking food down into a form the cells can use

3) Absorption: The ability of a cell to take in nutrients, water, gases, and other substances from its surroundings. 3) Absorption: The ability of a cell to take in nutrients, water, gases, and other substances from its surroundings.

4) Transport: being able to move nutrients, water, gases and other substances into and out of the cell 4) Transport: being able to move nutrients, water, gases and other substances into and out of the cell

5) Biosynthesis: The cellular process of building new chemical compounds for the purpose of growth, repair and reproduction. 5) Biosynthesis: The cellular process of building new chemical compounds for the purpose of growth, repair and reproduction.

6) Secretion: the release of substances from a cell 6) Secretion: the release of substances from a cell

7) Respiration: the release of energy from chemical breakdown of compounds within the cell 7) Respiration: the release of energy from chemical breakdown of compounds within the cell

8) Excretion: the ability of a cell to rid itself of 8) Excretion: the ability of a cell to rid itself of waste products waste products

9) Response: the ability of a cell to react to stimuli from its environment 9) Response: the ability of a cell to react to stimuli from its environment

10) Replication: the process of fission in which one cell divided to form two identical cell 10) Replication: the process of fission in which one cell divided to form two identical cell

11) Photosynthesis: the cellular process in which a plants makes food from water and carbon dioxide, using energy from the sun 11) Photosynthesis: the cellular process in which a plants makes food from water and carbon dioxide, using energy from the sun

Organization of Living Things

The Earth and everything in it is made up of smaller parts working together to make the whole. The Earth and everything in it is made up of smaller parts working together to make the whole. This type of organization is called a hierarchy. This type of organization is called a hierarchy.

Levels of Organization… we will go from the largest to the smallest Levels of Organization… we will go from the largest to the smallest 1) Biosphere: all earthly environments that support life 1) Biosphere: all earthly environments that support life

The biosphere is the most inclusive level of organization. The biosphere is the most inclusive level of organization. It includes both living and non- living elements on Earth. It includes both living and non- living elements on Earth.

2) Ecosystem: all organisms in an area and the physical components they interact with

Ecosystems include both biotic (living) features and abiotic (nonliving) features. Ecosystems include both biotic (living) features and abiotic (nonliving) features. Abiotic examples are elements, soil, water, temperature, and sunlight. Abiotic examples are elements, soil, water, temperature, and sunlight.

3) Community: all the organisms in an ecosystem Each organism within the community depend on each other for protection, food, etc.

4) Population: individuals of one species in one particular area at one time

5) Organism: an individual living thing It is the combination of all organ systems working together to form a living thing.

6) Organ System: a group of organs that work together for a particular function

7) Organ: a group of tissue that work together to complete a specific task

8) Tissue: group of similar cells that perform a specific function

9) Cell: the smallest unit of life They can be specialized to carry out specific functions.

10) Organelle: a membrane-bound structure inside a cell that perform a specific cellular job

11) Molecule: particles made of two or more atoms that are chemically bonded together

12) Atom: the smallest piece of physical matter Made up of protons, neutrons, and electrons Made up of protons, neutrons, and electrons

From the entire planet to all the way down to tiny atoms, these are all the things that work together to make life possible. From the entire planet to all the way down to tiny atoms, these are all the things that work together to make life possible.

Microscopes One of the most important tools in biology is the microscope. One of the most important tools in biology is the microscope. The type we will be using in the classroom is the compound light microscope. The type we will be using in the classroom is the compound light microscope.

A compound light microscope is a device that uses light to see small objects. A compound light microscope is a device that uses light to see small objects. It is considered “compound” because it uses a combination of at two lenses to magnify the object. It is considered “compound” because it uses a combination of at two lenses to magnify the object.

Parts of a compound light microscope: Parts of a compound light microscope: 1) ocular (eyepiece) what you look into, it has a lens in it which magnifies 10 times (10X). 1) ocular (eyepiece) what you look into, it has a lens in it which magnifies 10 times (10X).

2) Body Tube: connects the eyepiece to the objectives (lenses). 2) Body Tube: connects the eyepiece to the objectives (lenses).

3) Nosepiece: holds the objectives, it revolves to set the lenses into place 3) Nosepiece: holds the objectives, it revolves to set the lenses into place

4) Objectives are the magnifying lens. 4) Objectives are the magnifying lens. Most microscopes have 3 objectives. Most microscopes have 3 objectives.

If there are 3, the shortest usually magnifying 4x and is called the scanning lens. If there are 3, the shortest usually magnifying 4x and is called the scanning lens.

The middle sized lens is the low- power objective and magnifies 10x. The middle sized lens is the low- power objective and magnifies 10x.

The longest lens is usually the high-power objective and magnifies 40x or 43x larger. The longest lens is usually the high-power objective and magnifies 40x or 43x larger.

Because you always look through the eyepiece then the objective, to figure out the total magnification you must multiply the magnification of the eyepiece by the magnification of the lens. Example: 10x(eyepiece) times 40x(high-power lens) equals 400x.

5) Stage: the flat platform the slide sits on. 5) Stage: the flat platform the slide sits on. There is a hole in the stage (stage opening) that allows light through. There is a hole in the stage (stage opening) that allows light through.

6) Stage clips holds the slides in place. 6) Stage clips holds the slides in place.

7) Coarse adjustment knob (larger knob) moves the body tube to focus the image. 7) Coarse adjustment knob (larger knob) moves the body tube to focus the image. This knob should be used to find the object but never with the high-power objective. This knob should be used to find the object but never with the high-power objective.

8) Fine adjustment knob (smaller knob) moves the body tube slightly to bring the image into fine focus. 8) Fine adjustment knob (smaller knob) moves the body tube slightly to bring the image into fine focus.

9) Diaphragm regulates the amount of light passing to the slide. 9) Diaphragm regulates the amount of light passing to the slide.

10) Arm: supports the body tube. 10) Arm: supports the body tube. The microscope is usually carried by the arm. The microscope is usually carried by the arm.

11) Illuminator produces light or reflects light up through the slide. 11) Illuminator produces light or reflects light up through the slide. Can be a lamp or a mirror. Can be a lamp or a mirror.

12) Base is the bottom of the microscope and is for support. 12) Base is the bottom of the microscope and is for support.

Now let’s learn to use the compound light microscope. Now let’s learn to use the compound light microscope. How to Properly Prepare and Use a Microscope - YouTube How to Properly Prepare and Use a Microscope - YouTube How to Properly Prepare and Use a Microscope - YouTube How to Properly Prepare and Use a Microscope - YouTube