Sexual vs Asexual Reproduction

   Sexual reproduction has some benefits and some negative parts to it.  "An asexual female who appears in a population should have twice as many offspring as her sexual counterpart." (215).  This shows that asexual reproduction is much more efficient then sexual reproduction because it can do twice as much.  "After a brief and glorious flowering, asexuals vanish.  Which has led scientists to conclude that exclusive asexuality is an evolutionary dead end" (216).  This shows that without the mixing of genes organisms will become extinct very fast.  "'We have several ways. We pick up DNA that's loose in the environment.  We gather DNA from passing viruses.  We even plunder the genes of dead bacteria- the cognoscenti call it necrophilia.'" (217) This is an example of a asexual organism that plunders genes from other organisms to survive, E. coli.  "'Would be extremely different from each other.  Each will have accumulated different mutations.'"(222).  This quote shows how asexual organisms still create genetically different organisms through mutations.

Unit 3 Relection

   This unit was about cells and the many concepts related to them.  Early in the unit we learned about macromolecules.  These include proteins, lipids, carbohydrates, and nucleic acids.  They are the building blocks for all cells.  We learned where each macromolecule is in a cell by doing the macromolecule lab, in which we tested the different parts of an egg for the different macromolecules found in cells.  Later we learned about the membrane and how molecules diffuse through it.  This is done by the processes of osmosis, passive diffusion, facilitated diffusion, and active transport.  We learned more about this process in the egg diffusion lab in which we placed an egg in syrup and an egg in water and the egg in syrup lost it's water and shriveled up.  After that we learned how proteins are made in the different organelles of the cell and how they are transported outside of the cell.  In the tour of a cell vodcast we learned about all the organelles and their functions.  We later applied this knowledge to the microscopic organism lab where we identified the different organelles inside cells.  And in the end we learned about the process of photosynthesis and cellular respiration.  This unit went well and there where no major setbacks.  The content was easy to learn, and I had no trouble understanding the concepts that where taught in this unit.  I also did not have any problem working in the collaborative environment.

    From these experiences I learned what cells are made of and the processes that they do.  I learned that cells are made from the macromolecules lipids, proteins, carbohydrates, and nucleic acids and certain macromolecules are used to make certain parts of the cells.  I also learned how the macromolecules are produced in a cell.  The process of diffusion through cell membranes is interesting because it can take place in the many different ways of passive diffusion, facilitated diffusion, osmosis, and active transport.  Then most recently the concepts of photosynthesis and cellular respiration.  I would like to learn more about the cytoskeleton of a cell, we covered this topic very briefly and I believe that more could be done about this to reach a better understanding of this topic.  Also the process of mitosis I would like to learn more about and how one cell and divide into 2. 

Amoeba from the microscopic organism lab:

Results of the Egg Macromolecules Lab:

Results of the Egg Diffusion Lab:

Microscopic Organism Lab

Power: 400
This cell is unique because it has many mitochondria.
I observe the purple nucleus in the corners of the cells.
These cells are Eukaryotic and Heterotrophic.

Power: 400
This side it unique because it shows the vein of a plant and how molecules are transported to cells.
I observe that the cells have cell walls that are easy to see and the organelles are mostly transparent.
These cells are Eukaryotic and Autotrophic.

Power: 100
These cells are unique because the chloroplasts are lined up in a spiral line.
I observe that the cells in this algae form long chains.
These cells are Eukaryotic and Autotrophic.

Power: 400
These cells are unique from the other cells before this because they are significantly smaller.
I observe that these cells come in many different shapes and sizes.
These cells are Prokaryotic and Autotrophic.

Power: 400
This cell is unique because it makes energy from the sun but has no chloroplasts.  This is because they are the ancient chloroplasts that chloroplasts today evolved from.
I observe that these cells are in rings.
These cells are Prokaryotic and Autotrophic.

Power: 400
This cell is unique because it is both autotrophic and heterotrophic at the same time.
I see that the cell has a nucleus, flagellum, and also Chloroplasts.
This cell is Eukaryotic, Autotrophic, and Heterotrophic.

Power: 400
This cell is unique because they all have many different colors.
This cell is relatively large and have visible organelles and pseudopods.
This cell is Eukaryotic and Heterotrophic.

   In this lab we observed the prepared slides of these organisms under microscopes and recorded what we saw in the slides.  Then I took pictures of the slides and labeled them (the ones above).  This helped us understand the structure of the cells, both how they are arranged in muscle and leaf tissue, and how the organelles are inside the cell.

Cell Parts I was able to identify:

• Muscle cell: nucleus, muscle fiber, striations
• Ligustrum: chloroplasts, nucleus, cell wall, epidermis cell, vein
• Spirogyra: cell wall, chloroplasts, cytoplasm, nucleus
• Bacteria Cells: coccus, bacillus, spirilum, 
• Cynobacteria: rings of cynobacteria
• Euglena: nucleus, chloroplast, flagellum
• Amoeba: nucleus, cell membrane, pseudopods, mitochondria

Autotrophs have chloroplasts, or in the case of cynobacteria, are their own chloroplast.  They produce their own energy from light and store it as glucose.  Heterotrophs consume other organisms to acquire energy, they consume these other organisms by swallowing them in the cell membrane and then breaking down their nutrients with the lysosomes.  They usually have a flagellum or pseudopods to move around faster. Eukaryotes are more advanced cells that have their DNA stored inside a nucleus.  They have organells and they make up all the plants and animals that we know, as well as many types of single cellular organisms too. Prokaryotes are more primitive cells that are much older in origin but still most common.  Bacteria and Cynobacteria are prokaryotes.  They do not have a nucleus that stores the DNA and they do not have organelles, but they do have DNA which is in their cytoplasm.

Egg Diffusion Lab

   In this lab, we placed one egg in sugar (corn syrup), and another egg in deionized water for 48 hours.  The eggs had both been in vinegar for 48 hours to dissolve the egg shell, and had sat in water for a week prior to the experiment. 

   When we took the observations we found that the mass and circumference of the egg sample in sugar had decreased.  This had happened because the egg in the sugar solution was hypertonic, so it lost water to try to make an equal concentrations on both sides of the membrane.  The solvent of water diffused through the membrane to the lower concentration of water in the corn syrup.  The solute sugar had molecules to big to be moved through the membrane by passive diffusion so it stayed outside of the egg.  

   A cell's internal environment changes when its external environment changes because many molecules passively diffuse and the internal environment tries to mirror the external environment to reach equilibrium.  

   This lab demonstrates the concept of passive diffusion in which solvents on the side of the membrane with high concentration, will move through to the side of the membrane with low concentration to try to reach equilibrium in the concentration of the solutions.  This process does not require any energy.  

   Vegetables are sprinkled with water in markets to keep the solvent water the same concentration in the plant, preventing the plant from drying out and wilting.  plants along roadsides that are salted will become hypotonic and will gain too much water when the plant try's to reach equilibrium in the concentration of the salt and water inside the plant. 

   Based on this experiment I would want to learn more about how solutes effect multi-cellular organisms.  This could be done by seeing how salt or sugar would effect plants when they are watered a solution that has a solute inside it.

Group Data:

Class Data:

Egg Macromolecules Lab

   In different parts of the egg there are different types of macromolecules.  When the egg membrane was tested it was found that on a scale of 0-10 there where 10 proteins and 3 lipids.  This shows that the egg membrane contains proteins and lipids.  Since we know the molecular structure of the membrane, we can infer that the proteins in the membrane are transport proteins that allow molecules in or out of the cell.  The lipids in the membrane are the main structure of the membrane and the main composition of the egg membrane.  The egg white contains proteins and lipids too.  On the test they both scored a 6 on a scale of 0-10.  The proteins in the egg white are most likely enzymes to protect the egg from invasive growths.  The lipids in the egg white are to give the chicken nutrition inside the egg.  The egg yolk contains many proteins and a small amount of lipids.  For proteins it scored an 8, and lipids scored a 1 on the test.  The egg yolk is a basic structure for the chicken to grow and contains mostly proteins to grow.

   While our hypothesis supported our data our data might have been effected by a few factors.  One of these factors is that the original data was the qualitative color of the sample, quantified by scaling it from 0-10 based on the person's opinion, so there is still no exact number for it.  Also the observations where taken by 4 different people so the opinions would vary from person to person.  And lastly, the data was taken from only one set of data, and not the average of a large set of data which would be more accurate.   Due to these errors, in future experiments we could also have all the observations taken by one person.  Or we could take more sets of data to produce a more accurate result.  However with the time limitations of a class period this might not be realistic in a class setting.

   I would however, recommend a color key similar to the color key on ph tests, but for the different solutions we are using to test the egg.  This would help make our data more quantitative and accurate, so that each particular color has a designated number.  This lab was done to demonstrate which macromolecules where found in each particular part of the egg.  This understanding can be applied to which parts of the cell contain each macromolecule, since the egg is a very large cell.  From this lab I learned where each marcomolecule is inside a cell which helps me understand macromolecules and their uses in the different parts of the cell.  Based on my experience from this lab, I can understand what each particular macromolecule is used for, and I know how to use some of the solutions that we used to test for macromolecules.

The macromolecules that I tested for in lipids:

The macromolecules my group members tested for in proteins, polysaccharides, and monosaccharides: