LALA

Question 1

What are the components of DNA nucleotides?

Answer 1

• Deoxyribose sugar
• Phosphate group
• Bases A, T, C, G

DNA nucleotides are the building blocks of DNA.

Question 2

What are the components of RNA nucleotides?

Answer 2

• Ribose sugar
• Phosphate group
• Bases A, U, C, G

RNA differs from DNA by having uracil instead of thymine and an extra oxygen in the sugar.

Question 3

During transcription, RNA polymerase reads the template strand of DNA in which direction?

Answer 3

3’→5’

A complementary mRNA strand is synthesized in the 5’→3’ direction.

Question 4

What is the role of the coding strand in transcription?

Answer 4

Has the same sequence as mRNA (except T → U)

The coding strand is not directly used for synthesis but serves as a reference.

Question 5

How is mRNA read at the ribosome?

Answer 5

In codons (triplets)

Each codon specifies an amino acid, forming a polypeptide chain.

Question 6

What is the function of tRNA during translation?

Answer 6

• Carries specific amino acids
• Has anticodons complementary to mRNA codons

tRNA plays a crucial role in decoding mRNA into a protein.

Question 7

What is RNA processing?

Answer 7

Conversion of pre-mRNA into mature mRNA before translation

This step is essential for the proper expression of genes.

Question 8

What is the purpose of the 5’ cap in mRNA?

Answer 8

• Protects mRNA from degradation
• Aids ribosome binding

The 5’ cap is crucial for mRNA stability and translation initiation.

Question 9

What is the function of the poly-A tail?

Answer 9

• Stabilizes mRNA
• Assists nuclear export

The poly-A tail enhances the lifespan of mRNA in the cytoplasm.

Question 10

What is splicing in RNA processing?

Answer 10

Removes introns and joins exons

This process is vital for creating a functional mRNA molecule.

Question 11

What is alternative splicing?

Answer 11

Different combinations of exons are joined to produce multiple mRNA variants from one gene

This increases protein diversity without increasing gene number.

Question 12

What are the four levels of protein structure?

Answer 12

• Primary: amino acid sequence
• Secondary: α-helices and β-pleated sheets (H-bonds)
• Tertiary: 3D folding due to R-group interactions
• Quaternary: multiple polypeptide subunits

Each level of structure is crucial for the protein’s function.

Question 13

What distinguishes tertiary structure from quaternary structure?

Answer 13

• Tertiary: interactions within one polypeptide
• Quaternary: interactions between multiple polypeptides

Understanding these structures is essential for grasping protein functionality.

Question 14

What are the components of an amino acid structure?

Answer 14

• Central carbon
• Amino group (–NH₂)
• Carboxyl group (–COOH)
• Hydrogen
• Variable R group

The R group determines the properties of the amino acid.

Question 15

What role do R groups play in proteins?

Answer 15

• Determine polarity
• Determine charge
• Determine hydrophobicity

R groups influence protein folding and interactions.

Question 16

How can a point mutation affect a protein?

Answer 16

• Change an amino acid → altered folding → altered function
• Produce a non-functional protein

Mutations can have significant impacts on protein activity.

Question 17

What is meant by degeneracy in genetics?

Answer 17

Multiple codons can code for the same amino acid

This means some mutations are silent and have no effect on protein function.

Question 18

What is the function of sgRNA in CRISPR-Cas9?

Answer 18

Binds to a complementary DNA sequence via base pairing, guiding Cas9 to a specific site

sgRNA is essential for the specificity of the CRISPR system.

Question 19

What does Cas9 do in the CRISPR-Cas9 system?

Answer 19

Creates a double-strand break at the target DNA sequence

This action is crucial for gene editing.

Question 20

What are the two main DNA repair pathways?

Answer 20

• Non-homologous end joining (NHEJ): error-prone, causes insertions/deletions
• Homology-directed repair (HDR): uses a template for precise repair

These pathways determine the outcome of CRISPR editing.

Question 21

What is the difference between a knock-out and a knock-in?

Answer 21

• Knock-out: gene disrupted → loss of function
• Knock-in: new DNA inserted → altered or new function

These terms describe different types of genetic modifications.

Question 22

Define gene of interest and plasmid.

Answer 22

• Gene of interest: DNA sequence to be inserted
• Plasmid: small circular DNA vector used to carry genes

These are fundamental concepts in genetic engineering.

Question 23

What are restriction enzymes used for?

Answer 23

Cut DNA at specific sequences, producing sticky ends for complementary base pairing

They are essential tools in molecular cloning.

Question 24

What is the role of DNA ligase?

Answer 24

Joins DNA fragments by forming phosphodiester bonds

DNA ligase is crucial for DNA repair and replication.

Question 25

How do cells take up **plasmids**?

Answer 25

Via transformation (e.g. heat shock) ## Footnote This process is important for genetic engineering.

Question 26

What are **selectable markers**?

Answer 26

Genes (e.g. antibiotic resistance) that allow only transformed cells to survive and be identified ## Footnote Selectable markers are essential for identifying successful transformations.

Question 27

What is the purpose of **PCR**?

Answer 27

Amplifies a specific DNA sequence for: * Forensic analysis * Disease detection * Research ## Footnote PCR is a fundamental technique in molecular biology.

Question 28

What does gel electrophoresis do?

Answer 28

Separates DNA fragments by size: smaller fragments travel further ## Footnote It is used to analyze DNA samples.

Question 29

Why is **fragment size** important in gel electrophoresis?

Answer 29

Movement depends on size due to resistance in gel matrix ## Footnote Distance traveled is inversely proportional to fragment length.

Question 30

What are some common **trends** to identify in data analysis?

Answer 30

* Increase * Decrease * Correlation ## Footnote Identifying trends is crucial for drawing conclusions from data.

Question 31

What should you do to **evaluate effectiveness** in data analysis?

Answer 31

Determine if results show desired outcome and consistency ## Footnote This evaluation helps assess the reliability of findings.

Question 32

What are some **limitations** to consider in data analysis?

Answer 32

* Small sample size * Uncontrolled variables * Measurement error ## Footnote Limitations can impact the confidence in conclusions drawn from data.

Question 33

What is the difference between **GMO** and **transgenic** organisms?

Answer 33

* GMO: any organism with altered DNA * Transgenic: contains DNA from another species ## Footnote Understanding these terms is essential in biotechnology discussions.

Question 34

What are some **biological implications** of genetic modifications?

Answer 34

* Off-target effects * Unintended mutations * Ecological impacts * Ethical concerns ## Footnote These implications are critical in evaluating the risks of genetic engineering.