Mutations
What is Mutation?
A permanent, random change in an organism's DNA sequence
What type of cell undergoes meiosis?
Gamete cells.
What is the main action of enzymes?
They decrease the activation energy needed for a reaction to proceed.
Where does the mRNA go after it is produced in the nucleus?
It travels through the nuclear pores into the cytoplasm to find a ribosome.
What is genetic engineering?
The direct manipulation of an organism's genome using biotechnology to introduce desirable traits
Which cells can pass mutations to offspring?
Germ-line mutations (occur in sperm or eggs).
What is the purpose of meiosis?
To produce gametes (sperm/egg) for sexual reproduction and maintain a constant chromosome number across generations by halving them.
What is competitive inhibition?
It occurs when a molecule similar in shape to the substrate binds to the active site, blocking the actual substrate from binding.
What is a "codon," and how many bases does it have?
A codon is a sequence of three nucleotides on an mRNA strand that codes for one specific amino acid.
What is a "GMO"?
It stands for Genetically Modified Organism. It is any living thing (like a plant or animal) that has had its DNA changed by scientists in a lab.
What is a mutagen?
A chemical or physical agent (like UV light or chemicals) that causes mutations.
How many divisions occur and what are they called?
Two: Meiosis I (reduces ploidy) and Meiosis II (separates sister chromatids).
Are Enzymes consumed in the reaction or no?
No, Enzymes are not consumed in the reaction.
How does the correct amino acid get to the ribosome?
tRNA (transfer RNA) molecules act as "delivery trucks." Each tRNA has an anticodon that matches a specific mRNA codon, ensuring it drops off the correct amino acid in the right order.
Can scientists mix DNA from two different species?
Yes. For example, they can take a "glowing" gene from a jellyfish and put it into a fish or a plant to make it glow, too.
What is a silent mutation?
A mutation that occurs, usually in the third base of a codon, that does not change the amino acid sequence of the resulting protein
When does DNA replication occur?
Before Meiosis I (Interphase)
What is a enzyme?
A biological catalysts, typically proteins, that speed up chemical reactions by lowering activation energy without being consumed
What happens when the ribosome reaches a "stop" codon?
Translation is terminated. No more amino acids are added, and the newly formed polypeptide chain is released to fold into a functional protein
Are "genetic engineering" and "cloning" the same thing?
No, Genetic engineering changes the instructions to create something new. Cloning just copies the instructions to make an exact twin.
What is the difference between somatic and germ-line mutations?
Somatic mutations occur in body cells and are not inherited; germ-line mutations occur in reproductive cells and are passed on.
What happens in Metaphase II?
Individual chromosomes (sister chromatids) line up in single file along the equator.
How do enzymes speed up reactions?
They decrease the activation energy needed for a reaction to begin, allowing it to proceed much faster.
If the DNA sequence is TAC, what are the corresponding mRNA and tRNA sequences?
Is there genetic engineering in my food?
Likely, yes. In the US, most corn and soy are engineered to help them grow better and resist bugs.