Unit 4 - Lesson 1: Mutations and Antibiotic Resistance Flashcards
What is a genome?
A genome is the full set of DNA for an individual. It’s like an instruction manual to make you.
How many chromosomes makes up the human genome?
46 chromosomes (23 pairs).
What do chromosomes contain?
Many genes.
What are genes?
Genes are a section of DNA that codes for a protein. Each gene controls a certain characteristic, like eye colour.
How many chromosomes do you get from your mother and how many from your father?
You get one chromosome from mum and one from dad for each characteristic. 23 chromosomes from mum and 23 from dad.
What are the matching chromosomes from each parent together called?
A homologous pair.
Do homologous pairs naturally sit next to each other?
No.
Do homologous pairs share the same height and hold the same genes at the same positions?
Yes.
How many homologous pairs are there? How many remaining chromosomes are there and what are they?
22 homologous pairs. There’re 2 chromosomes remaining; they are your sex chromosomes. These determine if you’re male or female at birth.
What are variations of the same gene called?
Alleles. For example, dad may give you an allele for blue eyes and mum one for brown eyes. Both are eye colour genes.
Other than looks, what do genes control?
Your health. For example, some prevent cells growing uncontrollably (cancer).
What are sister chromatids results of?
Sister chromatids are the result of DNA replication before mitosis or meiosis. Each chromosome is copied and the copy is then joined to the original to make 2 sister chromatids.
Define mutation.
A rare, random change in an organism’s genetic material that can be inherited.
Give an example of a species that reproduces faster and therefore evolves faster.
Bacteria. E.coli can double in number every 15-20 minutes. They reproduce by binary fission, which is a type of mitosis. Mutations are rare, but with this high rate of reproduction, they become more common.
What are antibiotics for?
Antibiotics are given to fight bacterial infections. They don’t work on viral or fungal infections.
How do some antibiotics work?
Some antibiotics work by attacking the bacteria cell wall (made of murein, not cellulose like plants).
What if a bacterium carries an antibiotic resistant mutation?
It’ll survive when the others die. The resistant superbug will reproduce and may mutate again to produce a more deadly variant.
Write in 4 steps what would happen if a bacterium carries an antibiotic resistant mutation.
- A few bacteria mutate to be resistant to the antibiotic.
- The antibiotic kills all the other bacteria, leaving just the resistant bacteria.
- The resistant bacteria reproduce. Now we have lots of resistant bacteria.
- The bacteria mutate again to become more deadly.
How can we prevent antibiotic resistance?
Finish the full course of antibiotics given to you by the doctor.
Don’t take antibiotics for minor infections. Any time a bacterium comes into contact with antibiotics, it has a chance to develop a mutation against them.
What is a superbug?
A superbug is a bacteria that has evolved to be completely resistant to antibiotics. There’s a high chance of death or removal of the infected body part if you have a superbug.
What should you write instead of superbug in an exam?
An antibiotic resistant bacterium.
What should you write instead of “bacteria can be IMMUNE to antibiotics”?
Bacteria can be resistant to antibiotics.
Immunity is a human trait. Bacteria are not immune.
