Genetics (The Basics)

This week in AP Biology we talked about genetics.Genetics is the study of heredity and heredity is a process where a parent passes certain genes to their offspring. The main thing we discussed this week is Mendelian Genetics, which is pretty much mainly focused around punnet squares. Punnet squares are a diagram that predicts the outcome of offspring. For this to work you need the genotype from the father and the mother. A genotype is the genetic makeup of an organism. The genotype in a punnet square are the letters that stand for one or several genotypes in the mother and father. Another thing we talked about were recessive and dominant alleles. Recessive alleles are alleles that are suppressed when a dominant allele is present and a dominant allele is an allele that always shows up unless there is a homozygous recessive allele present. Genetics is a very simple subject to learn about, but it is also extremely interesting to talk about as well.


 

Genetics

This week in AP Biology we talked about genetics. In the beginning of the week, we went to a genetics conference at Lubbock. The conference was really interesting! The beginning of the conference wasn't all that interesting, but once we got into cloning, that's when it became extremely interesting. In the conference, scientist have learned that you can take human skin and turn them into stem cells to make a tiny human brain. Another thing that was really interesting at the conference was that scientist are trying to make a thing similar to a fountain of youth. Researchers and scientist are trying to make people who are in their 60's, 70's and so forth, to make them look like how they looked when they were in their 20's or 30's. Scientist are getting closer and closer to be able to clone humans. Since they have cloned goats, horses, and several other animals, they are getting really close to cloning a human. Even though most people and scientists say that it cannot be done because it is to complex, but researchers are figuring out a to make it possible. In my opinion I do not think it is a good idea to clone a human because people can take advantage of this and do crazy bad things. Another thing researches and scientist are trying to do is being able to cure diseases such as Parkinson's, Lou Gherig's Disease. And another thing they are trying to cure is diabetes. All of this is really crazy to think about. Diseases and other issues are starting to become a reality. Like the speaker at the genetics conference Sam Rhine said, science fiction, is more amazing than science fiction.

Meiosis Lab

This week in AP Biology we did a lab over meiosis. In the lab we had red and pink beads and a yellow magnet. With these things we had to make chromosomes and make an illustration with the beads to make them look like they are in interphase, prophase, metaphase, anaphase and telophase in mitosis and also the exact same but in meiosis. After that we had to get cards with a picture of crossing over. We had to count how many were in a 4:4 ratio or 2:2:2 ratio and so on and so forth. Once that was done, we would then have to find the percentages of ratios. The final thing we did was on the first day we started the lab, we put onion pieces in sand soaked in water and let them sit in a drawer for a few days, so the onions will start to grow tips.  We would then cut the tips and put them on a microscope slide with hydrochloric acid on the onion tip and then put it over a flame for 5 seconds. Once that was finished we had to put this special substance on the onion tip ( I forgot the name of it :(  ) and put it over a flame for about 2 minutes. We would then put it under a microscope a look to find the stages of interphase, prophase ,metaphase, anaphase and telophase.



  

Meiosis

This week in AP Biology we discussed about meiosis. Meiosis is a type of cell division that results in four daughter cells each with half the number of chromosomes of the parent cell, as in production of gametes and plant spores. Meiosis has two cell divisions, Meiosis I and Meiosis II. Meiosis I halves the number of chromosomes, while in Meiosis II, sister chromotids split.  Just like mitosis, meiosis goes through Prophase, Metaphase, Anaphase, Telophase, and Cytokensis, but these phases produce gametes and to simply make you, you. In Interphase I, DNA replicates and each chromosome becomes doubled.In Prophase I, crossing over occurs which makes two homolougous chromosomes line up next to each other. Once crossing over occurs, the chromosomes are no longer identical. In Metaphase I, homologous chromosomes line up along the equator of the cell. In Anaphase I, chromosomes pull apart from opposite ends of the cell. In Telophase I, the spindle fibers disintegrate and cytokinesis begins. Once cytokinesis is complete, Meiosis II begins. Meiosis II is very similar to mitosis. In Prophase II, the spindle fibers start to form. In metaphase II The chromosomes line up and each cell has only one of each homologous chromosome. In anaphase II, the sister chromotids move away from each other and in telophase II and cytokinesis, the formation of four genetically different haploid cells form.

The Cell Cycle

This week in AP Biology we talked about the cell cycle. The cell cycle is the life of a cell from the time it is first formed from a dividing parent cell until its own division into two cells. Without the cell cycle, our body would not be able to function how it does. Such as when you get a cut, it eventually heals because of mitosis.There are seven phases in the cell cycle. G1, Interphase, S, G2, Mitosis, M, and Cytokinesis. Each phase has a different job. In G1 the cell grows while carrying out cell functions unique to its cell type. In S phase the cell continues to carry put its unique functions. it also duplicates its chromosomes. The G2 phase is just the gap after the chromosomes have been duplicated and just before mitosis. Mitosis is a type of cell division that generates new cells for growth and repair. Cytokinesis is the division of the cell's cytoplasm. In the M phase, cell division occurs for a short amount of time the contents of the nucleus are evenly distributed to two daughter nuclei, and the cytoplasm divides in two. The other phases are Prophase, Metaphase, Anaphase, Telophase. In Prophase the chromatin becomes more tightly coiled into discrete chromosomes. In Metapahse, The microtubules move the chromosomes to the metaphase plate at the equator of the cell. In Anaphase, Sister chromatids begin to seperate, pulled apart by motor molecules interacting with kinetochore microtubules. In Telophase the nuclear envelopes re-form around the sets of chromosomes located at opposite ends of the cell. The cell cycle is a very important process to humans and animals. Without it, our body will not be or act how it does now.

Photosynthesis Lab

This week in AP Biology we did a lab on plant pigments and photosynthesis. In the first part of the lab you get a piece of chromatoraphy paper and rub a spinach leaf on top of it with a quarter, so the pigment of the spinach leaf will be on the paper. You then put the tip of the chromatography paper into an alcoholic solvent, so the pigments will travel up the paper. When the pigments are completely done traveling up the paper, you measure where each pigment ends ( carotene, chlorophyll a, chlorophyll b) and  you calculate Rf values by dividing the pigment with the solvent. In the second part of the lab you get a spinach leaf and use a hole puncher to punch holes in the leaf to make leaf discs. After that you put the leaf discs in a syringe. Once the leaf discs are in the syringe, you fill the syringe up with. When the leaf discs are in the syringe with the solution make sure to make the leafs sink to the bottom by vacuuming the air out. Once the leafs are sunk, you then put the leaf discs into a solution which is mixed with water and baking soda (which gives off carbon dioxide) and you put the the leaf discs under a light source and calculate how many float to the top every 30 seconds.

Photosynthesis

This week in AP Biology we discussed about photosynthesis. Photosynthesis is the process where plants use sunlight to synthesis their food from carbon dioxide and water. I have been taught photosynthesis since elementary, but I never knew how complicated and complex it really was until we started learning about it in depth. Photosynthesis occurs in the chloroplast of the plant.There are two parts to photosynthesis, and they are the light reaction and the Calvin Cycle (also known as the dark reaction) . The light reaction occurs in the thylakoid membrane and it converts light energy to make chemical energy. The light that is absorbed is used to make ATP and also produces NADPH. The Calvin Cycle uses ATP as an energy source and also consumes NADPH so it can add high energy electrons to make glucose (sugar). There are three phases in the Calving Cycle. The first phase is called Carbon Fixation which is when carbon dioxide is made into a five carbon sugar called ribulose biphosphate or RuBP. The second phase is Reduction which is when ATP and NADPH are used to convert 3 phosphoglycerate to glyceraldehyde 3 phosphate which is the predecessor to glucose and other sugars. And finally the third phase is Regeneration. Regeneration is when even more ATP is used to convert glyceraldehyde 3 phosphate back to RuBP (which is the acceptor for carbon dioxide) so the cycle is complete. For the Calvin Cycle to continue this, the light reaction must continue regenerating ATP and NADPH. Without photosynthesis, anything that needs oxygen to survive will not be alive without it. Photosynthesis is one of the most important processes to occur.