Unit 5 Reflection/ Notes

Unit 5 was the unit based off of… mutations. Problems with DNA, sometimes good, sometimes harmless, and sometimes detrimental. This unit went over point mutations, frameshift mutations, inversions, and translocations.

Point mutations are changes in one or two base pairs of DNA, and are small but common. These can be harmful if the protein changes a lot, but if the protein doesn’t really change they’re harmless. There are two main types of point mutations; substitution and frameshift mutations. In substitution, a nucleotide is substituted for another(ex. T is replaced by A by mistake). Frameshift mutations occur when a, insertion, where an extra base pair is added into the code, or b, deletion, where a base pair is left out of the code.

Some other mutations include inversion, where a piece of DNA breaks off and bonds in reverse order. Translation occurs when part of a chromosome breaks off and bonds with another chromosome.

Why do mutations matter to us though? First off, changes in DNA means changes in proteins, and some diseases are caused by the smallest of things, even a change of a single base. Mutations can be detrimental like said earlier, resulting in cancers or life threatening problems. Mutations can be very useful too. They could accidentally create new genetic variation for natural selection, causing resistances to certain things in nature.

Gene regulation is the reason why we don’t sprout hair on our eyes and ears on our chest. Cells don’t want to perform more than the necessary actions for the cell to function, so there is something called an operator that prevents the RNA polymerase from reading the gene. This is necessary, because without the operator the RNA polymerase would read the gene and keep making excess amounts of whatever results from the initiated process.

Unit 4 Notes

Unit 4 consisted of many steps and processes, all related to cells and development.  

• DNA fingerprinting- analyzes sections of DNA that have little to no known function but vary widely from one individual to another.     

• Gene theory- whenever there is an absent or faulty gene, it is replaced by a normal and working gene.
• The Human Genome Project- ongoing effort to analyze human DNA sequence.

Punnett squares are extremely useful  charts, made to draw possible phenotypes of an offspring based upon its parents’ genes.

Mendel’s work showed people the reason why we all look different, and why we all have different traits. His work taught us about dominance, recessiveness, and variation.

Two types of Inheritance: Autosomal and x-linked.

The Law of Segregation- Gene pairs for a trait separate when gametes are formed

Unit 3 Notes

Cells are called cells because a scientist, Robert Hooke, used an early compound microscope to look at a thin slice of cork. This cork showed many little chambers, almost as if they were “cells”. Hooke called these little chambers cells and they are known as cells to the present day. He used this microscope to look at other things, and found out that everything he looked at had “cells” as well.

The cell supports itself using different processes. Some of these processes create new organelles, some exterminate old, unproductive organelles, and some let things in and out of the cell.

Prokaryotes are cells with no nucleus, and lack many organelles compared to a eukaryote, which has all of those.

Unit 2 Notes

Photosynthesis is a process a plant cell undergoes to create ATP for the cell to work and for the plant to be supplied with energy. It converts energy from the sun and water from the roots in the soil to ATP using photosynthesis, which occurs in the chloroplast unique to plant cells.

Nucleus- nucleolus

Ribosome- small subunit(bottom), large subunite(top), builds proteins

Vesicle- membrane bound container

Rough ER- ribosome son the outside, “factory”

Golgi body- add stuff to proteins then “ships” the proteins

Cytoskeleton- structure

smooth ER- produces lipids, cholesterol, etc, detoxification

Mitochondria- produce atp, have own DNA

Vacuole- in plants, stores stuff

Cytosol- fluid that contains solutes, concentration gradient

Lysosome- Digestive enzymes, “suicide”

Centriole- important in positioning, initiate formation of spindle

Unit 1 Notes

Scientific method

1. Question/ problem
2. Collect information
3. Hypothesis
4. Experiment
5. Results/ data
6. Analysis/ conclusion(support/reject)

Qualitative- Descriptions

Quantitative- Numbers

Positive control- a group of data that will give predictable positive results

Negative control- A group of data lacking what is being tested so as to give expected negative results

Control- Something you use to compare your results to

Independent Variable- something that will change

Dependent Variable- something that will be measured

Constant- remains the same throughout experiment

Vocabulary

• Mutations- a change in the DNA code
• Mutagen- anything that causes a mutation
• Gene expression- process of a gene being used to produce a gene product or phenotype
• Gene regulation- mechanism used by cells to increase or decrease the expression of a gene
• Exons- sequences that are expressed
• Introns- sequences that are cut out
• Codominance- both traits are visible
• Incomplete dominance- Both partially show