UNIT 6 - Introduction to Biology
Purpose of the unit
The goal of unit 6 is to introduce you to biology. There are several big ideas that can be explored: evolution, systems, classification, etc. Our focus will be on how scientists are constantly trying to determine new classification structures for life.
In order to do this we will first have to learn how to use a microscope. As we will find out, a lot of the life we will explore is not visible to the naked eye. Therefore, we will learn how to use a microscope to examine these organisms and other microscopic objects. In addition, we will learn the fundamentals of life: what all living things have in common, what life needs to survive, and what scientists consider to be living.
This unit will be broken down into two primary lessons: microscopes and life.
In order to do this we will first have to learn how to use a microscope. As we will find out, a lot of the life we will explore is not visible to the naked eye. Therefore, we will learn how to use a microscope to examine these organisms and other microscopic objects. In addition, we will learn the fundamentals of life: what all living things have in common, what life needs to survive, and what scientists consider to be living.
This unit will be broken down into two primary lessons: microscopes and life.
Summary of Activities and Topics
Lesson 1: Microscopes
In our first activity, we were given posters of microscopes with unlabeled lines and an envelope that contained the labels. We also had a microscope on our tables. We attempted to label the microscopes parts without knowing what the parts are called or what they do. Yet, we managed to do this rather successfully because the parts have very obvious names. Further, the part names contain clues as to where the parts are and what they do!
Once we learned where the parts our, we completed our second activity on microscope anatomy. In this activity, we discussed what we thought each of the parts did. To do this, we used the microscopes and observed what happened when we used certain parts.
Having now learned the parts, we practiced focusing the microscope. In order to focus the microscope, we learned it was first important to lower the stage and use the red lens before placing the slide on the stage. This is to prevent any damage to the objective lenses. Once the slide is safely mounted, we raised the stage all the way up and then looked through the eyepiece. We lowered the stage while looking through the eyepiece until the image came into focus. Some students were successfully able to go to the medium objective lens and use the fine adjustment knob. The purpose of this activity was to teach us how to focus. However, it also let us work with some fun slides that contained microscopic words on them. Only one word on each slide was real and it was our goal to find that one word!
Next, we learned more about our microscopes. We learned how to calculate the power of magnification of our microscopes. To calculate this we need to know the magnification power of each lens. This is because power of magnification is the combined power of two or more lenses. We found that the eyepiece has a magnification power of 10X. The low (red), or small, objective lens have a magnification power of 4X. The medium (yellow) lens is 10X and the high (blue) lens is 40X. To calculate the power of magnification, you multiply the magnification power of two lenses together. For example, if we use the eyepiece (10X) with the low objective lens (4X), the magnification power would be 40X (4 x 10 = 40).
Once we learned about magnification we were able to take some time to practice drawing what we see using the microscope. There are a few "rules" that the team has developed to help us draw accurate images:
- always draw what you see (don't draw what isn't there)
- always draw to scale - always draw in color (expect for dyed images)
- always title your images, label them as needed, and include the magnification you use (40X, 100X, or 400X).
We practiced making drawings by looking at different colors of thread and looking at planarians.
Our last activity in learning how to use the microscopes was observing the letter "e". The purpose of this activity was two-fold: we learned how to make a wet mount slide and we learned that microscopes invert the image of what we are looking at. Further, we learned that what we do to the slide appears opposite when we look in the micropscope. For example, if we move the slide to the left, the image moves to the right.
In our last activity with the microscopes, we learned how to use the high power lens. The high power lens (400X) can be difficult to use. It has very high magnification and not-so-good resolution. Therefore, a lot of the specimens we look at with it can be blurry. However, it is necessary to use it to observe some of our specimens (pollen, bacteria, etc.) in more detail. We review the basic rules of using high power: always focus/center the specimen on low/medium power, be at eye level with the stage when rotating to high power, and only use the fine focusing knob when focusing on high power. These rules are in place to help you get a better image and to reduce the chance of damaging the lens. To practice using the high power lens, we observed pollen.
Lesson 2: Life
In the second lesson we begin exploring life. The first thing we had to do was understand what life is. To do this we completed the life sort activity. In this activity we received several cards with pictures. We attempted to classify each picture as showing something that was living or non-living. Most were easy but there were a few that were difficult: eggs, fingernails, and virus just to name a few examples. We learned that all living things tend to show several similar characteristics. Although there are many characteristics, we focused on 6: responding to stimuli, growth/development, reproduction, homeostasis, organization, and using energy.
Two terms we will see a lot are biotic and abiotic. It is very important to understand that these terms do not mean living and non-living. The term biotic refers to anything that is/was alive or is made by the body of an organism. Examples of things that are biotic include animals, plants, fungi, bacteria, protists, hair, blood, dead leaves, etc. All of these are either examples of organisms or are things made by organisms. The term abiotic refers to factors that affect organisms. Abiotic things are not organisms and are not created by an organism's body. Most commonly, abiotic factors refer to chemical and physical processes. For example: weather, sunlight, radiation, etc. To ensure we understand this, we completed an activity in which we attempted to classify objects as biotic or abiotic.
Lesson 3: Cells
In the next lesson of this unit we were introduced to cells. Cells are the smallest part of an organism that is considered to be alive. To introduce us to cells, we played a game called CellCraft. The purpose of this game, aside from being really fun, is to introduce us to the parts of a cell and to see how the cell works. During gameplay, we filled out a log of all the parts and processes we encountered. Not all of the parts we observed were actually part of a cell. But, those parts were still essential to understanding how the cell works.
Once we understood what was inside a cell, we asked a simple question: do all cells look the same? We observed slides of cells from plants, animals, and bacteria. What we found is that not all cells look the same. First, we discovered that bacteria cells are very different from plant and animal cells. This is because they do not contain a nucleus and they do not have proper organelles. Therefore, they are classified as prokaryotes (this means before the nucleus). Also, we discovered that they are much smaller than plant and animal cells. Plant and animal cells contain a nucleus and have organelles. Therefore, they are classified as eukaryotes. Plant cells have some cell parts and organelles that animal cells do not have. For example, they have a cell wall and they have chloroplasts; you can't find those in animal cells. Animal cells also have some parts that are not found in plant cells. For example, it is difficult to find lysosomes in plant cells but easy to find them in animal cells.
We also discovered that it is very difficult to see many organelles in cells. Therefore, we made diagrams of the plant, animal, and bacterial cells. Typically, we can only see the nucleus and sometimes the nucleolus. We can also see the cell membrane and cell wall. If we are observing plant cells, we can easily see the chloroplasts (it is important to note that not all plant cells contain chloroplasts. For example, root cells do not have chloroplasts).
We also observed that animal cells don't usually have a very defined shape (there are some animal cells that take on particular shapes; ex: blood cells). And, when looking at a large cluster of them, they aren't too well arranged: they look like a pile of cells (again, some cells in animals are highly structured; ex: muscle cells). However, in almost all plant cells we looked at, we noticed they were neatly arranged in rows, circles, etc. This is because the arrangement of the cells help provide the plant with support. Imagine building a brick wall: an organized, layered wall will provide more support than just a random pile of bricks.
All of this was complied and analyzed through our cell comparison sheet.
Lesson 4: Mitosis
Having learned about the cell, its parts, and the different types, it is time to start learning how cells function and stay alive. The first of these functions we will learn is mitosis. Mitosis is one of three phases of the cell cycle. The cell cycle is a series of phases a cell goes through throughout it life. The cell cycle is important to organisms because it helps organisms grow larger, develop, repair body damage, and replace dead cells. The three phases are: interphase, mitosis, and cytokinesis.
Interphase, which means between phases, is the longest of all the phases. During this time the cell grows, duplicates organelles, functions, etc. The second phases is mitosis, which means threading process. In mitosis, the cell makes a copy of the nucleus in preparation for splitting to make a new cell. Mitosis is the process that describes how the nucleus splits. The final phase, cytokinesis, which means movement of space, is when the cell actually divides in half.
Mitosis was what we focused on the most. Mitosis has four stages: prophase, metaphase, anaphase, and telophase. Each stage helps the cell get the chromosomes into place to create the new nuclei. The cell doesn't always exist perfectly in each stage. We can subdivide each phase into early and late phases. To see this, we were given images of the phases in early and late form (ex: early prophase, late prophase) and we attempted to put them into the correct order.
Once we understood what happened in each stage, we observed onion roots to see each of the stages. We found that most cells are in interphase and hardly any are in mitosis. This is because mitosis is a short process (relative to interphase). However, we were able to see all four phases occurring in the onion root. We chose an onion root because the root is constantly growing. Therefore, the cells will be dividing regularly. Thus, we can see mitosis and cytokinesis occurring.
This summary is not yet complete. Last update: 3/16/12
In our first activity, we were given posters of microscopes with unlabeled lines and an envelope that contained the labels. We also had a microscope on our tables. We attempted to label the microscopes parts without knowing what the parts are called or what they do. Yet, we managed to do this rather successfully because the parts have very obvious names. Further, the part names contain clues as to where the parts are and what they do!
Once we learned where the parts our, we completed our second activity on microscope anatomy. In this activity, we discussed what we thought each of the parts did. To do this, we used the microscopes and observed what happened when we used certain parts.
Having now learned the parts, we practiced focusing the microscope. In order to focus the microscope, we learned it was first important to lower the stage and use the red lens before placing the slide on the stage. This is to prevent any damage to the objective lenses. Once the slide is safely mounted, we raised the stage all the way up and then looked through the eyepiece. We lowered the stage while looking through the eyepiece until the image came into focus. Some students were successfully able to go to the medium objective lens and use the fine adjustment knob. The purpose of this activity was to teach us how to focus. However, it also let us work with some fun slides that contained microscopic words on them. Only one word on each slide was real and it was our goal to find that one word!
Next, we learned more about our microscopes. We learned how to calculate the power of magnification of our microscopes. To calculate this we need to know the magnification power of each lens. This is because power of magnification is the combined power of two or more lenses. We found that the eyepiece has a magnification power of 10X. The low (red), or small, objective lens have a magnification power of 4X. The medium (yellow) lens is 10X and the high (blue) lens is 40X. To calculate the power of magnification, you multiply the magnification power of two lenses together. For example, if we use the eyepiece (10X) with the low objective lens (4X), the magnification power would be 40X (4 x 10 = 40).
Once we learned about magnification we were able to take some time to practice drawing what we see using the microscope. There are a few "rules" that the team has developed to help us draw accurate images:
- always draw what you see (don't draw what isn't there)
- always draw to scale - always draw in color (expect for dyed images)
- always title your images, label them as needed, and include the magnification you use (40X, 100X, or 400X).
We practiced making drawings by looking at different colors of thread and looking at planarians.
Our last activity in learning how to use the microscopes was observing the letter "e". The purpose of this activity was two-fold: we learned how to make a wet mount slide and we learned that microscopes invert the image of what we are looking at. Further, we learned that what we do to the slide appears opposite when we look in the micropscope. For example, if we move the slide to the left, the image moves to the right.
In our last activity with the microscopes, we learned how to use the high power lens. The high power lens (400X) can be difficult to use. It has very high magnification and not-so-good resolution. Therefore, a lot of the specimens we look at with it can be blurry. However, it is necessary to use it to observe some of our specimens (pollen, bacteria, etc.) in more detail. We review the basic rules of using high power: always focus/center the specimen on low/medium power, be at eye level with the stage when rotating to high power, and only use the fine focusing knob when focusing on high power. These rules are in place to help you get a better image and to reduce the chance of damaging the lens. To practice using the high power lens, we observed pollen.
Lesson 2: Life
In the second lesson we begin exploring life. The first thing we had to do was understand what life is. To do this we completed the life sort activity. In this activity we received several cards with pictures. We attempted to classify each picture as showing something that was living or non-living. Most were easy but there were a few that were difficult: eggs, fingernails, and virus just to name a few examples. We learned that all living things tend to show several similar characteristics. Although there are many characteristics, we focused on 6: responding to stimuli, growth/development, reproduction, homeostasis, organization, and using energy.
Two terms we will see a lot are biotic and abiotic. It is very important to understand that these terms do not mean living and non-living. The term biotic refers to anything that is/was alive or is made by the body of an organism. Examples of things that are biotic include animals, plants, fungi, bacteria, protists, hair, blood, dead leaves, etc. All of these are either examples of organisms or are things made by organisms. The term abiotic refers to factors that affect organisms. Abiotic things are not organisms and are not created by an organism's body. Most commonly, abiotic factors refer to chemical and physical processes. For example: weather, sunlight, radiation, etc. To ensure we understand this, we completed an activity in which we attempted to classify objects as biotic or abiotic.
Lesson 3: Cells
In the next lesson of this unit we were introduced to cells. Cells are the smallest part of an organism that is considered to be alive. To introduce us to cells, we played a game called CellCraft. The purpose of this game, aside from being really fun, is to introduce us to the parts of a cell and to see how the cell works. During gameplay, we filled out a log of all the parts and processes we encountered. Not all of the parts we observed were actually part of a cell. But, those parts were still essential to understanding how the cell works.
Once we understood what was inside a cell, we asked a simple question: do all cells look the same? We observed slides of cells from plants, animals, and bacteria. What we found is that not all cells look the same. First, we discovered that bacteria cells are very different from plant and animal cells. This is because they do not contain a nucleus and they do not have proper organelles. Therefore, they are classified as prokaryotes (this means before the nucleus). Also, we discovered that they are much smaller than plant and animal cells. Plant and animal cells contain a nucleus and have organelles. Therefore, they are classified as eukaryotes. Plant cells have some cell parts and organelles that animal cells do not have. For example, they have a cell wall and they have chloroplasts; you can't find those in animal cells. Animal cells also have some parts that are not found in plant cells. For example, it is difficult to find lysosomes in plant cells but easy to find them in animal cells.
We also discovered that it is very difficult to see many organelles in cells. Therefore, we made diagrams of the plant, animal, and bacterial cells. Typically, we can only see the nucleus and sometimes the nucleolus. We can also see the cell membrane and cell wall. If we are observing plant cells, we can easily see the chloroplasts (it is important to note that not all plant cells contain chloroplasts. For example, root cells do not have chloroplasts).
We also observed that animal cells don't usually have a very defined shape (there are some animal cells that take on particular shapes; ex: blood cells). And, when looking at a large cluster of them, they aren't too well arranged: they look like a pile of cells (again, some cells in animals are highly structured; ex: muscle cells). However, in almost all plant cells we looked at, we noticed they were neatly arranged in rows, circles, etc. This is because the arrangement of the cells help provide the plant with support. Imagine building a brick wall: an organized, layered wall will provide more support than just a random pile of bricks.
All of this was complied and analyzed through our cell comparison sheet.
Lesson 4: Mitosis
Having learned about the cell, its parts, and the different types, it is time to start learning how cells function and stay alive. The first of these functions we will learn is mitosis. Mitosis is one of three phases of the cell cycle. The cell cycle is a series of phases a cell goes through throughout it life. The cell cycle is important to organisms because it helps organisms grow larger, develop, repair body damage, and replace dead cells. The three phases are: interphase, mitosis, and cytokinesis.
Interphase, which means between phases, is the longest of all the phases. During this time the cell grows, duplicates organelles, functions, etc. The second phases is mitosis, which means threading process. In mitosis, the cell makes a copy of the nucleus in preparation for splitting to make a new cell. Mitosis is the process that describes how the nucleus splits. The final phase, cytokinesis, which means movement of space, is when the cell actually divides in half.
Mitosis was what we focused on the most. Mitosis has four stages: prophase, metaphase, anaphase, and telophase. Each stage helps the cell get the chromosomes into place to create the new nuclei. The cell doesn't always exist perfectly in each stage. We can subdivide each phase into early and late phases. To see this, we were given images of the phases in early and late form (ex: early prophase, late prophase) and we attempted to put them into the correct order.
Once we understood what happened in each stage, we observed onion roots to see each of the stages. We found that most cells are in interphase and hardly any are in mitosis. This is because mitosis is a short process (relative to interphase). However, we were able to see all four phases occurring in the onion root. We chose an onion root because the root is constantly growing. Therefore, the cells will be dividing regularly. Thus, we can see mitosis and cytokinesis occurring.
This summary is not yet complete. Last update: 3/16/12
Last year's Notes
A few "warnings" about these notes:
1. These notes often cover more information that what we learned in class. Don't waste your time trying to memorize these notes.
2. The reflection exams are written based on our activities, discussions, and discoveries made in class. This is why it is a reflection exam. They are designed to help you reflect on our activities to see what we have learned about. The exams are not written on these notes.
3. The information in the notes will differ from the information we learn in class. This is because the notes contain very scientific information. The activities we do in class lead us to general information. For example, in class we may do an activity to learn the definition of a term. The notes will also have that definition but will have it worded differently. In either case, both definitions are fine. But, the definition to keep in mind is the one we create in class.
4. These notes are updated as of 2011. Information may have changed since then. Some of these notes may have incorrect information in them. Again, this is why I want you to focus on our activities in class.
1. These notes often cover more information that what we learned in class. Don't waste your time trying to memorize these notes.
2. The reflection exams are written based on our activities, discussions, and discoveries made in class. This is why it is a reflection exam. They are designed to help you reflect on our activities to see what we have learned about. The exams are not written on these notes.
3. The information in the notes will differ from the information we learn in class. This is because the notes contain very scientific information. The activities we do in class lead us to general information. For example, in class we may do an activity to learn the definition of a term. The notes will also have that definition but will have it worded differently. In either case, both definitions are fine. But, the definition to keep in mind is the one we create in class.
4. These notes are updated as of 2011. Information may have changed since then. Some of these notes may have incorrect information in them. Again, this is why I want you to focus on our activities in class.
Microscopes
Below are two sets of notes from last year's class on microscopes. Please note that these sheets contain more information than we covered in class. The exam will not be designed on these notes. The exam is designed based on the activities we complete in class.
| microscopes_teacher.pdf |
| anatomy_answers.pdf |
Life
Below are last year's notes on natural evidence. Please note that these sheets contain more information than we covered in class. The exam will not be designed on these notes. The exam is designed based on the activities we complete in class.
We took notes in class on life. Please refer to them.
