Is Sex Important?

Some advantages of sexual reproduction are that genes vary between generations. Also, changing genes can get rid of harmful mutations that the parents may have accumulated in their genes according to Muller's theory. When their are offspring that have many harmful mutations, those mutations will not be passed on and will end there. A disadvantage to sexual reproduction, as claimed by Dr. Tatiana is that there is competition between males and that qualities that attract a mate may not be the same qualities needed to survive.

An advantage to asexual reproduction is that to keep the population the same, each female needs to have one offspring, as supposed to two in sexual reproduction. Also, asexual organisms have been living on earth the longest according to Miss Philodina. A disadvantage to asexual reproduction is the susceptibility to diseases. The red queen theory points out that if one asexual organism is susceptible to a certain disease, than the entire population can be wiped out by a single disease.

Something I would like to know is why some species reproduce asexually and others sexually.

Unit 3 Reflection

This unit was all about cells and their functions. The unit started just by familiarizing ourselves with the cells parts and how it works. Once we had an understanding of the cells parts, concepts like osmosis and diffusion were introduced. Having an understanding of that led to learning about photosynthesis and cellular respiration. I did not fully understand the material presented at the beginning, but working as a group on things like labs really helped me understand the content. I was able to finish the homework on time which gave me an advantage during class, but I did miss a vodcast causing me to be behind the next class.

Some major concepts I learned in this unit that may be helpful were diffusion, photosynthesis, and cellular respiration. These things will be useful to know in future science classes. I also learned that finishing the homework on time or early gave me a huge advantage and that missing or putting off homework made it harder for myself.

I want to learn more about the process of photosynthesis. It was a little confusing so I will re-watch the vodcast on it and re-read the textbook on it. I will do this to be prepared for the test. I may also watch some other vodcasts on things I had trouble with and study my textbook notes to be prepared.

Microscopic Organism Lab

Muscle cell: Nucleus, Striations

Ligustrum: Epidermis Cell, Veins, chloroplasts

Spirogyra: Cytoplasm, chloroplast, cell wall

Bacteria: Bacillus, Coccus, Spirilum

Cyanobacteria: Single cells

Euglena: Nucleus, Chloroplasts

Amoeba: Nucleus, Cell membrane, Pseudopods

The autotrophs we observed had cell walls. They also had chloroplast which made them green. The heterotrophs on the other hand did not have cell walls, making them have less structure and different colors. In the eukaryotes, I could identify different parts of the cell and organelles. Prokaryotes, however, do not have organelles and were much simpler than the eukaryotes. 

Photosynthesis Virtual Lab

Photosynthesis Virtual Labs.

Lab 1: Glencoe Photosynthesis Lab

http://www.glencoe.com/sites/common_assets/science/virtual_labs/LS12/LS12.html

Analysis Questions

1. Make a hypothesis about which color in the visible spectrum causes the most plant growth and which color in the visible spectrum causes the least plant growth?

If plants are exposed to different colors of light, than the plant exposed to red or blue light will have the most growth, while the plant exposed to green light will grow the least.

2. How did you test your hypothesis? Which variables did you control in your experiment and which variable did you change in order to compare your growth results?

I tested the hypothesis by exposing the plants to each color of light for 30 days. A variable I controled was the type of plant. I changed the color of light in each test.

Results:

Filter Color	Spinach Avg. Height (cm)	Radish Avg. Height (cm)	Lettuce Avg. Height (cm)
Red	18.3	12.6	11
Orange	14.6	8	6
Green	2	1.3	3
Blue	19.3	14	12
Violet	16.3	10.1	8

3. Analyze the results of your experiment. Did your data support your hypothesis? Explain. If you conducted tests with more than one type of seed, explain any differences or similarities you found among types of seeds.

The data did support my hypothesis. The plants exposed to red or blue light consistently grew the tallest and the green light plants grew the least in each of the tests. The order of best light to worst light was consistent through all of the plants.  

4. What conclusions can you draw about which color in the visible spectrum causes the most plant growth?

I can conclude that the colors blue, red, and violet point to more plant growth, while colors like green lead to poor plant growth.

5. Given that white light contains all colors of the spectrum, what growth results would you expect under white light?

White light would produce a height that is the average of these tests.

Site 2: Photolab

http://www.kscience.co.uk/animations/photolab.swf

This simulation allows you to manipulate many variables. You already observed how light colors will affect the growth of a plant, in this simulation you can directly measure the rate of photosynthesis by counting the number of bubbles of oxygen that are released.

There are 3 other potential variables you could test with this simulation: amount of carbon dioxide, light intensity, and temperature.

Choose one variable and design and experiment that would test how this factor affects the rate of photosynthesis. Remember, that when designing an experiment, you need to keep all variables constant except the one you are testing. Collect data and write a lab report of your findings that includes:

• Question
• Hypothesis
• Experimental parameters (in other words, what is the dependent variable, independent variable, constants, and control?)
• Data table
• Conclusion (Just 1st and 3rd paragraphs since there's no way to make errors in a virtual lab)

In this lab we attempted to answer the question of how does temperature affect photosynthesis in plants. I found that the higher the temperature, the less photosynthesis that occurred. I know this because at 10°C there were the most bubbles indicating photosynthesis was occurring and the more the temperature was increased, the fewer bubbles appeared. Scientific studies show that temperature affects the light independent reaction in photosynthesis. This supports are data in saying that photosynthesis slowed down.

This lab was done to demonstrate how temperature affects the rate of photosynthesis. A major concept learned from this is how photosynthesis works and how certain factors can affect how efficiently it works. Based on my experience from this lab, I know know better on how photosynthesis works which could help me on future labs.

Data:

Water Temperature (C)                                            Bubbles per 5 seconds

10	6
25	5
40	2

*Type your question, hypothesis, etc. below.  When done, submit this document via Canvas.  You may also copy and paste it into your blog.

Amoeba

Power: 400x
This aboeba is unique because it uses its cell membrane to devour other cells. I observed that the aboeba came in many sizes, shapes, and colors. This cell is eukaryotic, because it has organelles and is a heterotroph because it eats other organism to get its energy.

Euglena

(The flagellum is not visible in this picture)
Power: 400x
Euglena cells are unique because they can be both autotrophic and heterotrophic. I observed that it is very green, which means that it has lots of chloroplasts. It is a eukaryote because it has a nucleus and organelles but is not classified as a autotroph or heterotroph.

Cyanobacteria

Power: 400x
This cell is unique because it consists of many cells together. I noticed that they often form chains of cells. Cyanobacteria are prokaryotes like other bacteria. These cells are autotrophic, because they carry out photosynthesis.

Bacteria Cells

Power: 400x
These bacteria cells are unique because they come in several shapes and sizes. Something I observed is that the bacteria cells are extremely small compared to the other cells. The bacteria are prokaryotic because they do not have any organelles or a nucleus. They are heterotrophs because they don't make their energy, but instead get energy from other organisms.

Spirogyra

Power: 400x
This cell is unique because most of the cell is taken up by the central vacuole, pushing all of the organelles to the outside. I noticed that the cell is very long and skinny. This cell is a eukaryote, because you can see organelles like the nucleus and chloroplasts. It is autotrophic because it has chloroplasts and makes its own energy through photosynthesis.

Ligustrum Plant Cells

Power: 400x
This organism is unique because in this view you can see several different types of cells. I observed that the inner cells that do the photosynthesis are greener because they contain more chloroplasts than the outer epidermis cells. These cells are eukaryotes, because they have nuclei and organelles like mitochondria and chloroplast. These cells are also autotrophs, because they make their own energy using photosynthesis.

Skeletal Muscle Tissue

The power used on the microscope to take this photo was 400x.
This cell is unique because unlike many other cells it has multiple nuclei in each cell. I observed that each cell is very long and tube-like. This muscle cell is eukaryotic because it has a nucleus and organelles. It is heterotrophic because it gets its energy from other organisms.

Egg Diffusion Lab

Looking at the class data, the mass and circumference of the egg increased when placed in the deionized water and decreased when placed the sugar water. The change occurred because of the solution's attempt at balancing the concentration of macromolecules in and out of the egg. The egg contains large amounts of solute compared to the deionized water solvent. Water than diffused into the egg to make the concentrations of solute equal, causing the egg to enlarge. When placed in the sugar water there was a higher concentration of solute outside of the egg, so the solvent, water, diffused out of the egg to balance out the concentration. The result was a deflated looking egg with a lowered mass and circumference.


A cells interior environment can change as its exterior environment changes. This could be to maintain homeostasis, or internal conditions of an organism. When the cell was put in vinegar first, and then water, and then either deionized water or sugar water. This caused the egg to diffuse water many times, either in or out of the cell.

This lab was all about the scientific principle of diffusion and osmosis. Diffusion is a cell letting molecules in and out of the membrane. It demonstrates this by showing how water can move in and out of a cell when the environments between them vary.

Fresh vegetables are sprinkled with water so they will absorb that water making it more juicy and to preserve freshness. Roads are salted to melt ice, but causes plants on roadsides to dry up. They dry up because their is a higher concentration of salt outside the plant, so it will loose water to try and balance out that concentration.

Another experiment that could be made based off this experiment and what we learned, could be an experiment about molecules diffusing across a cell membrane. The previous experiment was about how water diffuses across the membrane, so this experiment will teach us about how molecules diffuse.

Egg Cell Macromolecules Lab

In this lab we asked the question of what macromolecules would be present in different parts of a egg cell. We tested for the macromolecules, protein, monosaccharide carbohydrates, polysaccharide carbohydrates and lipids.

The presence of lipids was tested on an egg membrane and were found to be abundant. The data showed the abundance of lipids because when the membrane was exposed to chemicals, the chemical had an immense color change. This would make sense because the cell membrane is mostly made of lipids.

In the protein test, proteins were found to be prominent in the egg white of the egg cell. When exposed to the chemical that identifies protein presence, the chemical changed color rapidly, indicating that many proteins were present in the egg white. This is logical because the cytoplasm/egg white of a cell is made of proteins to be used as structure, and a food source.

When the egg yolk was tested for macromolecules, the most common macromolecules were monosaccharides. When tested with the chemical the chemical changed from blue to orange, signifying that large amounts of monosaccharide sugars were found in that portion of the egg. It would make sense that sugar would be found in the yolk, because the yolk is where the embryo develops and the sugars provide energy and food.

All but one of the evidences supported our claims. We claimed that proteins would be the most common in egg whites and that lipids would be found in the membrane, but did not hypothesis that the yolk would contain lots of monosaccharides.


While our data largely supported or hypothesis, some errors may have taken place in the procedure. It is possible that some of the transfer pipettes and spoons could have been mixed with different substances while carrying out the procedure. Also, a different person judged each test, possibly skewing results with differing opinions of scaling the color change. These could have caused the data to be invalid, because of inconsistency. To reduce possible errors in future experiments, we can try to be careful of mixing substances and have one person to be the judge of all the chemicals so the data will be consistent.

This lab was preformed to demonstrate where the macromolecules we studied are found in a cell and to deeper the understanding of how they work and what they do. In class we learned about the different types of macromolecules and what they do, and this lab showed how they were present in a cell and why they were in different parts of the cell. This lab taught me how I should carry out a procedure in a lab, because this lab was very messy and that could have been fixed by being more careful. Also, we took to long on the lab and the cleanup process took to long. In the future I will be more focused on doing labs as quickly and efficiently as possible.