Core Competencies Self-Assessment

Introduction

Over the past few days in A&P, we have been learning about DNA technologies. The ability to modify the genetic code has been one of the most exciting advances in modern science. One of the most powerful tools for gene editing is CRISPR-Cas9, a technology that allows scientists to target, modify, and repair DNA with precision. This tool has opened up new possibilities in medicine, agriculture, and biotechnology, offering solutions for genetic disorders, enhancing crop yields, and more. In the following sections, we’ll explore how CRISPR-Cas9 works, its ability to “knock out” genes, repair mutations, and its wide range of benefits to society.

What is CRISPR-Cas9?

CRISPR-Cas9 is a genome editing tool that allows scientists to modify parts of the genome by removing, adding, altering sections of the DNA sequence. CRISPR is short for “clustered regularly interspaced short palindromic repeats,” these are repeating sequences found in the DNA genome of bacteria. Cas9 stands for CRISPR-associated protein 9.

CRISPR-Cas9 consists of two key molecules:
-Cas9, a scissor-like enzyme that can cut DNA at a specific location so that then bits of DNA can be added or removed
-Guide RNA, which guides Cas9 to the right part of the genome

How does CRISPR-Cas9 target, bind, and cleave, and repair to “knock out a gene?”

-The process begins with targeting, where CRISPR-Cas9 uses gRNA to locate the specific DNA sequence to be edited. The gRNA is designed with a 20-nucleotide sequence complementary to the target DNA. The Cas9 protein scans the genome for a short DNA sequence known as the PAM (Protospacer Adjacent Motif).

-The binding starts once Cas9 locates the PAM. It starts by unwinding the DNA near the site. The gRNA then attempts to form base pairs with the complementary DNA strand. If the sequence matches a sequences of about 20 nucleotides within the gRNA, then they will start binding through complementary base pairing.

-The base pairings triggers Cas9 to change its 3D structure, which activates its nuclease activity- makes specific cuts in the DNA at a position three nucleotides upstream from the PAM sequence. This results in a double-stranded DNA break.

-CRISPR-Cas9 knocks out a gene by creating a double-stranded break at a specific DNA site. The cell repairs this break using Non-Homologous End Joining (NHEJ), an error-prone process that often introduces small insertions or deletions. These can disrupt the gene’s coding sequence, causing frameshift mutations or premature stop codons, which render the gene nonfunctional.

How does CRISPR-Cas9 repair a mutation in DNA?

Sometimes instead of NHEJ, the process undergoes Homology Directed Repair. This process is more efficient as instead of the randomization that can create errors in NHEJ, HDR uses templates that accurately repair the cleavage sites. These templates can also be modified to allow scientists to pick the function of the final protein as this process is repeated at every target gene. They do this by introducing donor DNA. By introducing donor DNA sequences, scientists can remove the originally unwanted DNA and  consistently replace it with the donor DNA.

How can CRISPR-Cas9 be used to our benefit?

CRISPR-Cas9 can be used to our benefit with how it allows scientists to rewrite the genetic code in almost any organisms while also being simpler, cheaper, and more precise than previous gene editing techniques. It also has many benefits in numerous fields such as, curing genetic diseases like cystic fibrosis and Huntington’s disease, creating drought-resistant crops, defeating viruses, and producing useful medicines.

A) Analyzing models

The model was able to accurately show the process and the basic steps. The labels and colors made it easy to tell which was which. Although, because it’s pretty simple and 2D, it doesn’t really accurately represent the 3D shape it really has as well as the interactive simulation did. I think, personally, it would be more representing if somehow it could be in a 3D shape that we could hold and alter ourselves.

B) Are models an effective way to educate others about science? Why or why not?

I believe models are effective for educating others because they provide visuals examples on ideas, instead of just words on a page. Interactive models also help engage learners, like making concepts more memorable.

I want to explore the theme of love in my art work. I’ve always been curious about the thought of love. Is it a feeling? Is it a choice? What does it look like? How should it be like? I want my art to include some swans, as in my research I found that they symbolize love. Their mating ritual involves bowing their heads which also symbolizes a heart so I think it’s perfect. While doing this art assignment, I would like to find my own meaning of romantic love and what it might look like to me.

What makes the swans so special?

For the Atomic Theory unit, a strength I had was knowing about orbital diagrams. I can draw them, and remember the order using the periodic table. A weakness I had was understanding the periodic table trends. I kept forgetting the whys, like why does the size of this atom increase when an electron is added, or why does this atom have a larger ionization energy than this one?
I had many weaknesses in the Bonding unit, because there were many terms I had a hard time understanding. One of the weaknesses was figuring out if a molecule was polar or non-polar. I didn’t quite understand how to use symmetry and if it cancels or not. Another weakness I had was drawing VESPR diagrams for molecules. Though, I was able to recognize the VESPR shapes, which was a strength I had.
The Mole unit was mostly math, which I liked. A strength I had was determining empirical formulas. I can find the molar mass, and use it to figure the mole, then find the ratio and divide it. One of my weaknesses is the unit conversions, especially the word problems. I know that the fractions are supposed to cancel, but I kept messing up which unit should go first, and this messes up the whole math.

Collaboration Rubric
Lab Skills Rubric
Personal Responsibility Rubric

Core Competencies