Mitosis Lab & Meiosis

     Today we started off by doing a lab on the different stages of mitosis in both plant and animal cells. We observed an onion root tip cells and animal cells under a microscope and drew pictures of the cells we observed going through the various stages. First interphase - DNA replication is occurring within the nucleus but physically it looks normal. The nucleus is intact and dark surrounded by cell walls. The second phase is prophase - the nucleus dissapears. The third phase is metaphase - the chromosomes line up in the middle. The fourth phase is anaphase - spindle fibers pull the two chromatids apart which forms two daughter chromosomes. And lastly telophase - a new nuclear enveloped forms around the two and if cytokinesis occurs there will be the formation of a cell wall between the two.

     After this we practiced our knowledge by looking at pictures of cells and counting the cells in each phase. This also told us how long the cells spend in each phase. Cells spend the majority of their lives in interphase.

     The mitosis I just talked about only occurs in body cells and some gametic cells. Other cells go through Meiosis. 

     Meiosis is similar, first the cells go through interphase consisting of G1, S and G2 stages, the same as in mitosis. G1 you have mom and dad DNA. In S, DNA is replicated and you have twice as much DNA. In G2 nothing really happens. Then Prophase 1 occurs, the nucleus dissapears. Then metaphase 1 - chromosomes line up in the middle, homologous structures together. Then anaphase 1 - pulled apart by spindle fibers. Telophase 1 - forms temporary nucleus and cell wall around two new cells. Prophase 2 - nucleus disappears. Metaphase 2 - line up in middle. Anaphase 2 - pulled apart. Telophase 2 - four nuclei and cell walls are formed.

    We practiced this repeatedly and noticed that almost every time we did it, a different combination of alleles came out. These random combinations are genetics, what we learned about last unit.

Unit 5 Project & Microscopes

     Today in class we started by getting our tests back. We then talked about the Unit 5 project and had time to work on them. I used this time to research the different organelles for eukaryotic plant and animal cells and prokaryotic cells. I also worked a little bit on my prezi.
     After this we learned how to properly use the two different types of microscopes in the classroom. We looked at a dog flea, cheek cell from our cheek, plant cell, and a sample taken out of one of the fish tanks in the classroom. We looked so closely that we could even see the cell walls and chloroplasts in the plant cells.

TEST DAY

We took the unit 4 test today! And I found out I got all 1s on my lab report (I think) SO I'M HAPPY YAYYYYY.

Pedigrees

     Today in class we learned how to interpret and create pedigrees, which are basically a family tree with genetics. We learned how to determine if the pedigree depicted a gene which is Autosomal (normal) or Sex-linked. We do this by determining if the gene appears more in males or if it appears in males and females about equally. We can then look at the parents genotypes (if given) and their offspring to see if the gene is dominant or recessive. We practiced with these for a while, and even did a hard problem to determine within a huge family who the carriers (heterozygous individuals) are.

Genetics AGAIN

     This class we learned about co-dominance, incomplete dominance, and sex linked genes. Co-dominance is when a single gene has more than one dominant allele and when an individual is heterozygous, both alleles will be shown. An example of this is blood type, type A and B are both dominant, so an individual with both will have AB blood, as opposed to one or the other. Incomplete dominance. Incomplete dominance is when a heterozygous offspring shows a mixture of the two alleles. For example, a red flower and a white flower have an offspring which is a pink flower. Sex-linked is when, for example, an x linked gene is passed onto a son, the son will always show that trait, even if it is recessive, because he doesnt have another X chromosome to show the dominant trait, he has a Y chromosome, however if it is passed to a daughter it doesn't always show.

Genetics #2

     This class we learned two ways to find phenotypic and genotypic ratios when we have two or more genes. We practiced these and took a quiz on them. I personally like the Fitz way because it is faster, but sometimes it is easier to see it using the Quick way. 

Genetics

Today we started learning about genetics! We did problems solving punnet squares. We also learned some basic vocabulary necessary for this unit. For example Heterozygous means having both alleles, A and a. Homozygous is two of the same alleles, either AA or aa depending on whether it is homozygous dominant or homozygous recessive. We learned about a carrier, which is a person who is heterozygous. F1 generation which is the first offspring of the parents, and F2 generation which is the offspring of F1.

Unit 3 Test

Today we took our Unit 3 DNA Test.

Hand/Flower Response

Hand and Flower Response

Flower: Transposons have inserted themselves into the genes of the flower which has caused the striped color. These are also called jumping genes, which we have read about for homework. 

Hand: This would occur when a scientist takes tissue from the pinky side of a limb bud and transplants it on the other side very early in development. This causes the limb to have a full extra set of fingers

Operon System

Today we learned about the operon system, because it is related to both the lab and protein synthesis. The operon system controls protein synthesis and signals when it should start and stop. This is only in prokaryotes. There are two types, repressible, which goes from on to off, and inducible which goes from off to on. Repressible represses the ability to make a protein until it is turned off. Inducible induces protein synthesis when turned on.