DNA vs. RNA
What sugar does DNA contain that RNA does not?
Deoxyribose
What are the two main processes of protein synthesis?
Transcription & Translation
What is a mutation?
A change in the DNA sequence
What type of mutation can be passed from parent to offspring?
Chromosomal mutation
Why are different genes expressed in different cells? What is this called?
Cells turn genes on or off based on their function and environment through gene regulation
What base does RNA have that replaces thymine in DNA?
Uracil
What molecule is created during transcription?
mRNA
What type of mutation occurs when one base is changed, but the reading frame remains the same?
Point mutation
Can a mutation in skin cells be inherited? Why or why not?
No, because it’s a somatic (body cell) mutation or gene mutation – it only affects that individual
What can be a positive effect of mutations?
It can increase genetic diversity like new traits or resistance to disease
True or False: DNA is found in the nucleus, but RNA can leave the nucleus
True
Where does translation occur?
At the ribosome
What type of mutation shifts the reading frame and affects all codons after it?
Frameshift mutation
What is one example of a chromosomal mutation?
Deletion, duplication, inversion, translocation
How can a mutation lead to cancer?
If it occurs in tumor suppressor genes, like p53, leading to uncontrolled cell growth
What type of RNA carries genetic instructions from the nucleus to the ribosome?
mRNA – Messenger RNA
How many bases are in a codon, and what does a codon code for?
3 bases, codes for 1 amino acid
Which is generally more harmful, a point mutation or a frameshift mutation? Why?
Frameshift – it alters every amino acid after the mutation
True or False: Some mutations have no effect on an organism.
True – silent mutations don’t change the protein
What is the difference between gene expression and regulation?
Expression- protein made or trait we see
Regulation- Combination of internal and external factors depending on cell type that tell which genes to be read and expressed
Name two structural and two functional differences between DNA and RNA
Structure: DNA = double-stranded, RNA = single-stranded; DNA has thymine, RNA has uracil.
Function: DNA stores genetic information, RNA helps make proteins.
If a DNA sequence is TAC-GGC-ATA, what would the corresponding mRNA sequence be?
AUG-CCG-UAU
Name one environmental factor that can cause mutations.
Radiation, chemicals, viruses, replication errors
Are mutations ALWAYS harmful?
No- They create genetic variation, which can lead to beneficial traits over time
Explain how we get from calls that can do everything to cells with a specific job or function? Why is this important?
Through cell differentiation the cell is told which genes are active in each cell, so only necessary proteins are made to complete that job. Without this we would not be able to function as multi-cellular organisms, as each individual cell would be trying to do everything.
Example: Eye cells making rods and cones to give us sight only or stomach cells making hydrochloric acid to help break down food only. - wouldn't be able to do their job otherwise.