Hi biology student! My name is Nakul Nagaraj (follow me on instagram @nakul_nagaraj), and I am now a sophomore at Saratoga High School. It may be a bit scary because it is your first day, but Mr. Orre's class isn't too hard if you know what you are doing.
In the beginning of each class, you will complete the "Do Now" on the board and then review the vodcast. Make sure you do every vodcast on time because if you miss one they are hard to catch up on. Also, if you don't do the vodcast, you will have no idea what is going on in class. They are also usually the only homework you will have for this class. Plan on spending 20 minutes on each vodcast. Another thing that you do this class that you may not be used to in a blog. Every time you do a lab or finish a unit you will write a reflection on your blog. You usually have time to do this in class and don't have to do it for homework.
Mr. Orre is usually pretty forgiving and understanding but he will get made if you don't use your common sense and do dumb things. Something he also hates is when people don't listen to instructions and he has to repeat himself. Remember that homework is worth more of your grade than tests so don't procrastinate. As long as you review the unit before a test you should do fine on the test. Some mistakes I made early on were procrastinating the textbook notes you do each unit, not doing a vodcast, and stressing too much about the tests.
I think that this is a pretty good class. You will probably hear some negative things about this class but you will definitely learn a lot. Make sure you stay on top of things and follow directions and you will do great in this class.
From,
Nakul
Thursday, June 1, 2017
Tuesday, May 30, 2017
Pig Dissection
The purpose of this lab was to learn about the anatomy and physiology of a pig and how it relates to our bodies. The internal organs of a pig are similar in location and function to those of a human. This unit we learned about all the organ systems and functions of the human body. This dissection allowed us to see first hand how the systems fit and linked together to work in the body. My favorite part of the dissection was probably the end, because all the organs were exposed and I could clearly see how they all fit together and worked. I think it was a valuable experience because it was really cool and I learned a lot about how the body works.
Tuesday, May 9, 2017
Unit 9 Reflection
In this unit we learned about taxonomy and how organisms are classified into their kingdoms, phyla, and classes. The more closely related organisms are, the more close they are classified. We looked at the tree of life a lot, and how it shows evolutionary relationships. It also shows where and when species became reproductively isolated and that shows why organisms have the features they do today. Organisms are divided into domains, kingdoms, phyla, classes, orders, families, genuses, and finally species. This classification helps scientists organize species. They also use cladograms, which show evolutionary relationships and traits.
There are three Domains in the three domain system. Eukaryota, Bacteria and Archaea. Archaea are like bacteria but certain traits cause them to be in a separate domain. They live in some of the most harsh environments on earth, often without oxygen. Bacteria are also single celled and have no nucleus. They are in two kingdoms, gram-positive and gram-negative. Viruses are technically not living but some theorize that they are the origin of life on this planet.
The Domain Eukaryota contains the kingdoms protists, plantae, animalia, and fungi. All eukaryotic cells have a nucleus. Protists are organisms that are hard to classify, and therefore it is the most diverse kingdom. Plantae is all plants, including vascular and non-vascular plants. Plants do photosynthesis to create energy for themselves. Fungi are very different from plants. They are heterotrophic, and one of the main decomposers. They have cell walls that are made of chitin and can reproduce sexually or asexually. The typed of fungi are bread molds, sac fungi, and club fungi.
The Domain Animalia contains all animals. 97% of animals do not have a backbone. The most primative animal is the sponge. Cnidarians are similar but are more complex and have tissue. Flatworms can move around but do not have a complete digestive tract. Mollusks have a digestive tract and a respiratory system. Arthoropods include insects, and have a exoskeleton. Crustaceans are similar to arthropods but in the water. Echinodermata have a water vascular system that can allow them to move.
Vertibrates make up the rest of the animal kingdom. All vertibrates are part of the phylum chordata. Agnatha were the first vertibrates and were jawless fish. Condricthyes are fish that have a jaw and cartilage skeleton. Osteicythes have jaws and bony skeletons. Amphibians are the transitionary class because they could live in water and land. The tiktallic was a trainsitional species that could get out of water and climb on land. This was a big breakthrough, because it allowed other species to evlolve to live on land.
Reptiles are ectothermic, cold blooded, and have 3 chambered hearts. Aves, or birds, have hollow bones and feathers. Mammals are endothermic and have complex reproductive and behavioral traits. Humans are mammals and have millions of years of ancestry and evolution to have the traits we have today.
There were no hard or complex concepts in this unit, only lots of content. There are a lot of phyla with certain characteristics to remember. Some questions I have are how do species develop new traits and even organs? How many more species are out there that we have not yet discovered? What species will take over once humans go extinct?
I think my presentation on the banana went pretty good. One thing I did not take into account was that I would speak faster in the presentation compared to practice, and therefore my presentation was a little bit short. I wanted to make eye contact and engaging with the audience a priority in my presentation, as I found it very boring to watch other people stand in the front of the room and read off a screen. To make sure I did not do this, I looked at the screen for a second every time I changed a slide so I could see what was on it and speak to the class about it. Presenting is a useful skill to have, as selling an audience or convincing a directed audience to agree with you or support you is extremely valuable.
There are three Domains in the three domain system. Eukaryota, Bacteria and Archaea. Archaea are like bacteria but certain traits cause them to be in a separate domain. They live in some of the most harsh environments on earth, often without oxygen. Bacteria are also single celled and have no nucleus. They are in two kingdoms, gram-positive and gram-negative. Viruses are technically not living but some theorize that they are the origin of life on this planet.
The Domain Eukaryota contains the kingdoms protists, plantae, animalia, and fungi. All eukaryotic cells have a nucleus. Protists are organisms that are hard to classify, and therefore it is the most diverse kingdom. Plantae is all plants, including vascular and non-vascular plants. Plants do photosynthesis to create energy for themselves. Fungi are very different from plants. They are heterotrophic, and one of the main decomposers. They have cell walls that are made of chitin and can reproduce sexually or asexually. The typed of fungi are bread molds, sac fungi, and club fungi.
The Domain Animalia contains all animals. 97% of animals do not have a backbone. The most primative animal is the sponge. Cnidarians are similar but are more complex and have tissue. Flatworms can move around but do not have a complete digestive tract. Mollusks have a digestive tract and a respiratory system. Arthoropods include insects, and have a exoskeleton. Crustaceans are similar to arthropods but in the water. Echinodermata have a water vascular system that can allow them to move.
Vertibrates make up the rest of the animal kingdom. All vertibrates are part of the phylum chordata. Agnatha were the first vertibrates and were jawless fish. Condricthyes are fish that have a jaw and cartilage skeleton. Osteicythes have jaws and bony skeletons. Amphibians are the transitionary class because they could live in water and land. The tiktallic was a trainsitional species that could get out of water and climb on land. This was a big breakthrough, because it allowed other species to evlolve to live on land.
There were no hard or complex concepts in this unit, only lots of content. There are a lot of phyla with certain characteristics to remember. Some questions I have are how do species develop new traits and even organs? How many more species are out there that we have not yet discovered? What species will take over once humans go extinct?
I think my presentation on the banana went pretty good. One thing I did not take into account was that I would speak faster in the presentation compared to practice, and therefore my presentation was a little bit short. I wanted to make eye contact and engaging with the audience a priority in my presentation, as I found it very boring to watch other people stand in the front of the room and read off a screen. To make sure I did not do this, I looked at the screen for a second every time I changed a slide so I could see what was on it and speak to the class about it. Presenting is a useful skill to have, as selling an audience or convincing a directed audience to agree with you or support you is extremely valuable.
Wednesday, April 19, 2017
Geologic Timeline Individual Reflection
The first major event in Earths history was the beginning of photosynthesis in cynobacteria. This is important because it increased the oxygen content in the atmosphere which led to the rise of eukaryotes and later plants and animals. Animals cannot survive without enough oxygen so we would not be here if it had not been for this event.
The second major event was the Permian extinction at the end of the Paleozoic Era. It was the largest mass extinction in Earth's history killing 80% of all life. This loss of life was necessary for the explosion of new life that happened afterwards. The absence of many species allowed dinosaurs to occupy the empty niches and start the era of Dinosaurs.
The third important event happened in the tertiary period when birds, mammals and flowering plants began to dominate. This happened when the dinosaurs went extinct after the cretaceous and the evolution of mammals led to the first humans. Without this event humans may not exist or be much different than what we are today.
The scale of Earth's history is incredibly massive. It surprised me looking at the timeline that all the eras and periods we talk about are all in the span of only about a meter. The Earth was barren with little to no life for most of history. When reading about it it seems that all the eras and periods are roughly the same length but looking at it you can see that the Precambrian Era is most of Earth's history.
Humans have had such a great impact on Earth in just a few hundred years. And most of our impact has happened in the last hundred. We are destroying ecosystems that took hundreds of millions of years to evolve in just years. Humans have existed for just a few thousand years, and have done more in a blink than any other species has done in millions of years.
Some questions I have are why did it take so long for life to take off and start evolving? Why did some species go extinct? Where there intelligent species in the past that went extinct? Why did the planet evolve the way it did?
The second major event was the Permian extinction at the end of the Paleozoic Era. It was the largest mass extinction in Earth's history killing 80% of all life. This loss of life was necessary for the explosion of new life that happened afterwards. The absence of many species allowed dinosaurs to occupy the empty niches and start the era of Dinosaurs.
The third important event happened in the tertiary period when birds, mammals and flowering plants began to dominate. This happened when the dinosaurs went extinct after the cretaceous and the evolution of mammals led to the first humans. Without this event humans may not exist or be much different than what we are today.
The scale of Earth's history is incredibly massive. It surprised me looking at the timeline that all the eras and periods we talk about are all in the span of only about a meter. The Earth was barren with little to no life for most of history. When reading about it it seems that all the eras and periods are roughly the same length but looking at it you can see that the Precambrian Era is most of Earth's history.
Humans have had such a great impact on Earth in just a few hundred years. And most of our impact has happened in the last hundred. We are destroying ecosystems that took hundreds of millions of years to evolve in just years. Humans have existed for just a few thousand years, and have done more in a blink than any other species has done in millions of years.
Some questions I have are why did it take so long for life to take off and start evolving? Why did some species go extinct? Where there intelligent species in the past that went extinct? Why did the planet evolve the way it did?
Thursday, April 13, 2017
20 Time Project Update
I am still set on the path I identified in my last blog post. I am on track for working with Mr. Fitzgerald to help him in his garden. I further researched native plants and how to grow them in a greenhouse (Mr. Fitz plans on having a greenhouse built soon). Also, a possible project on building a worm bin may be available for me so I researched that too. Basically, I have been doing a lot of reading and research to learn more about my topic and be prepared when its time for me to take the next step in my project.
Friday, April 7, 2017
Unit 8 Reflection
Unit 8 was about evolution and how and why species evolve. Evolution can be measured as a change in the frequency of an allele in the gene pool. The gene pool is the the total number of genes in a population. One of the main forces that sparks change in the gene pool is natural selection, the theory that the "winners," or individuals with better traits survive and reproduce to pass their genes on while the individuals with traits that don't help survival die and take their genes with them. We explored this in the Hunger Games Lab. When we tested this, the individuals with traits that helped them pick up food increased in population while the individuals with bad traits nearly died off. The allele frequency was graphed and showed the allele frequency change, showing that evolution was occurring.
The type of natural selection exhibited in this lab was directional selection, where one extreme phenotype, in this case the pincher, was favored so the phenotypes shift towards that. Stabilizing selection is where the average phenotype in the middle are favored and extremes are not. This keeps the population from changing. Disruptive selection is when both extremes are favored and the graph splits in two. This is often the beginning of speciation.
Natural selection is not the only thing that can change allele frequency. Genetic drift is when random acts kill random members of the population, eliminating them from the gene pool. This can be harmful because it lowers genetic variation. Gene flow is movement of alleles between populations, and mutations can also change allele frequency. Sexual selection traits are traits that increase chance of mating but do not help an individual survive.
New species are created in a process called speciation. When a species is reproductively isolated, they begin to drift apart until they are two different species. They become different species in a process called evolution. There is evidence to prove evolution exists. There are certain traits that modern day organisms have that are useless but would have been useful to ancestors. Also, similarities between species point to a common ancestor in the distant past.
Earths vast history is split up into eras, periods, and epochs. Mass extinctions mark the end of many of these. Each time period has different characteristics.
This unit was not a very difficult unit, but the scale of the Earth's timeline is hard to comprehend. Some questions I have are how did unicellular organisms turn into multicellular organisms and then plants and animals. Also how did asexually reproducing organisms evolve and become sexually reproducing.
I have had a chance to be more assertive in the geological timeline project. I have realized that there is a time to be a leader and be slightly more aggressive for the better of the group, but also a time to sit back more passively to better the group. But mostly, I have been assertive by leading with clear logical steps and listening to the ideas of others.
http://www.course-notes.org/biology/topic_notes/33_behavioral_ecology/fecundity_selection
New species are created in a process called speciation. When a species is reproductively isolated, they begin to drift apart until they are two different species. They become different species in a process called evolution. There is evidence to prove evolution exists. There are certain traits that modern day organisms have that are useless but would have been useful to ancestors. Also, similarities between species point to a common ancestor in the distant past.
Earths vast history is split up into eras, periods, and epochs. Mass extinctions mark the end of many of these. Each time period has different characteristics.
This unit was not a very difficult unit, but the scale of the Earth's timeline is hard to comprehend. Some questions I have are how did unicellular organisms turn into multicellular organisms and then plants and animals. Also how did asexually reproducing organisms evolve and become sexually reproducing.
I have had a chance to be more assertive in the geological timeline project. I have realized that there is a time to be a leader and be slightly more aggressive for the better of the group, but also a time to sit back more passively to better the group. But mostly, I have been assertive by leading with clear logical steps and listening to the ideas of others.
Wednesday, March 29, 2017
Hunger Games Final Analysis
1. In this lab we simulated generations of a population by having each generation have to get enough food to survive and reproduce.
2. The pincher was the most successful at getting food because it could do it very easily and quickly, leading to survival and reproduction.
3. The population did evolve because the allele frequency changed. The allele frequency was roughly equal in the beginning but by the third generation the A allele only consisted of 3% of the total alleles and the a allele was 97%. This is a drastic change in the allele frequency, and it showed in the phenotypes as most of the populations were pinchers, with few knucklers and no stumpys while the amount of each phenotype was equal in the beginning.
4. The food placement was often random and reproduction usually created a random offspring (given that the traits were present). Sometimes the food was not random and favored some over others. This could affect evolution because it can favor some without the best traits and cause some with the best traits to die to to chance.
5. If the food was smaller it may favor pinchers even more, but if it was large it may favor stumpys instead. If the food source changes or one food source goes down or extinct individuals with certain traits who were not favored before may be favored then.
6. the results may have been different if there was no incomplete dominance. There would be no knucklers, only stumpys and pinchers. At one point in the lab the stumpys went extinct but came back thanks to the knuckers. If they went extinct with no incomplete dominance they wouldn't be able to come back.
7. Evolution is caused by natural selection. Natural selection picks the individuals with the best survival traits to survive and reproduce. By weeding out the bad traits, those soon disappear or become less common while the better traits become more common, changing the population.
8. Individuals often mated with other individuals of the same phenotype, which cause the knucklers and stumpys to stick around. This relates to sexual selection found in nature. To increase chances of survival individuals sometimes cheated to get their food and stole from others. This can also happen in nature.
9. In evolution populations evolve. Natural selection acts on the genotype which affects the phenotype. Natural selection affects what genes are passed from parents to offspring which determines their traits.
10. What are more examples of events or things that could change a population? How have humans affected this process?
2. The pincher was the most successful at getting food because it could do it very easily and quickly, leading to survival and reproduction.
3. The population did evolve because the allele frequency changed. The allele frequency was roughly equal in the beginning but by the third generation the A allele only consisted of 3% of the total alleles and the a allele was 97%. This is a drastic change in the allele frequency, and it showed in the phenotypes as most of the populations were pinchers, with few knucklers and no stumpys while the amount of each phenotype was equal in the beginning.
4. The food placement was often random and reproduction usually created a random offspring (given that the traits were present). Sometimes the food was not random and favored some over others. This could affect evolution because it can favor some without the best traits and cause some with the best traits to die to to chance.
5. If the food was smaller it may favor pinchers even more, but if it was large it may favor stumpys instead. If the food source changes or one food source goes down or extinct individuals with certain traits who were not favored before may be favored then.
6. the results may have been different if there was no incomplete dominance. There would be no knucklers, only stumpys and pinchers. At one point in the lab the stumpys went extinct but came back thanks to the knuckers. If they went extinct with no incomplete dominance they wouldn't be able to come back.
7. Evolution is caused by natural selection. Natural selection picks the individuals with the best survival traits to survive and reproduce. By weeding out the bad traits, those soon disappear or become less common while the better traits become more common, changing the population.
8. Individuals often mated with other individuals of the same phenotype, which cause the knucklers and stumpys to stick around. This relates to sexual selection found in nature. To increase chances of survival individuals sometimes cheated to get their food and stole from others. This can also happen in nature.
9. In evolution populations evolve. Natural selection acts on the genotype which affects the phenotype. Natural selection affects what genes are passed from parents to offspring which determines their traits.
10. What are more examples of events or things that could change a population? How have humans affected this process?
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