B1 Flashcards
Name the 2 types of cells
Prokaryotic, Eukaryotic
What cell/s are eukaryotic?
Animal, Plant
What cell/s are prokaryotic?
Bacterial
Out of prokaryotic and eukaryotic cells, which have a nucleus?
Eukaryotic
What is the nucleus?
They contain genetic material
What is the cytoplasm?
A gel-like substance where most chemical reactions occur
What are the mitochondria?
They contain enzymes required for the reactions in aerobic respiration
What does a plant cell contain that an animal cell doesn’t?
Cell wall, Chloroplasts
Since prokaryotic cells do not have nuclei, where can genetic information be stored?
One long circular chromosome in the cytoplasm, Plasmids
What is a gene and what do they code for?
A short length of DNA on a chromosome, which codes for a specific sequence of amino acids, which make up a protein
What makes up a nucleotide?
Sugar, Phosphate, Base
What are the 4 different bases?
A, T, G, C
What are the complementary base pairs?
A & T, G & C,
Describe the process of protein synthesis
DNA unzips and is made into mRNA. This then leaves the nucleus and goes into the cytoplasm, where it attaches to the ribosome. Amino acids are then joined together in the right order by the ribosome following the order of the triplets in mRNA. This creates the protein
Why are substitution mutations not always impactful?
Sometimes the amino acid is coded for by multiple different triplet codes, so they don’t always change the genetic code
What is your genotype?
The alleles you have
What is your phenotype?
The characteristics you display
What is the genome?
All the genetic information of a cell/organism
What must your scientific drawing of a specimen not have?
There must be no shading or colouring and no broken lines
Why when you are using a light microscope, if you have a thick specimen, do you have to take a thin slice off?
To allow the light through the specimen so it can be seen through the micropscope
When and why do you have to add a drop of stain to specimens?
When using a light microscope, if your specimen is colourless/transparent, you can add a stain so it can be seen more easily
What are chromosomes?
One long molecule of DNA
If DNA is the polymer, what is the monomer?
Nucleotides
If proteins are the polymers, what are the monomers?
Amino acids
What 2 things influence the characteristics one display?
One’s genotype and environment
What are triplet codes and what do they code for?
They are 3 bases in the gene and code for a specific amino acids
What are insertion mutations?
When a new base is inserted into the DNA base sequence where it shouldn’t be
What are the effects of insertion mutations?
They cause a knock on effect, shifting every base one along, causing many amino acids to be changed
What are deletion mutations?
When a base is removed from the the DNA base sequence
What are the effects of deletion mutations?
They cause a knock on effect, shifting every base one along, causing many amino acids to be changed
What are substitution mutations?
When a base in DNA base sequence, is swapped for a different base
What are the effects of substitution mutations?
They can cause an amino acid to be be changed, but they do not cause a knock on effect, and sometimes do not change anything
What can coding mutations cause?
They can change the structure and function of the final protein, which can sometimes lead to changes in ones phenotype
What are gametes?
The reproductive cells (e.g. sperm and eggs)
What are alleles?
An allele is one of the possible forms of a gene. Most genes have two alleles, a dominant allele and a recessive allele
What is it when you are homozygous for a trait?
When you has two of the same alleles for that particular gene (e.g. CC or cc)
What is it when you are heterozygous for a trait?
When you has two different alleles for that particular gene (e.g. Cc)
How can genomes identify genetic variants that are involved with a gene and how can this help us to test people for a disease?
You can compare the genomes of people with and without the given disease, and from that see what is genetically different between the people with and without the disease. People can then be tested for the genetic variant which is found in someone with the disease
State 3 things genetic variants can cause and how genetic testing helps
1) An increased likelihood of developing a certain disease- if you are tested for this type of variant then you can make lifestyle choices to reduce the likelihood of developing the disease 2) You to definitely have a certain disease- if you are tested for this type of variant then you can begin treatment early 3) Can make some drugs less effective- if you are tested for this type of variant then doctors can only prescribe medicine that will be effective for you
What are the drawbacks of genetic testing?
If someone is tested for a certain variant, it could lead to- 1) Discrimination- e.g. employers may discriminate against people who are genetically likely to get a disease 2) Increased stress/anxiety- e.g. if you knew you were susceptible to a brain disease, you could seriously panic and stress every time you get a headache
How is genetic testing useful for family planning?
A couple wanting to have a baby could use genetic testing to identify the risk of their baby having a genetic disorder
What does genetically testing the parents do?
It can reveal whether parents have / are a carrier of a genetic disorder
What does genetically testing the embryo do?
Couples who know they are at risk of passing down a genetic disorder may choose to get their eggs fertilised in a lab- this way, the doctor can test each embryo and an embryo without the genetic variant can be implanted in the womb
What does genetically testing the fetus do?
The fetus can be tested for genetic variants linked with a given disorder
What is a risk of genetically testing the fetus?
It can increase the likelihood of a miscarriage
What are the drawbacks of genetic testing in family planning?
1) Testing isn’t 100% accurate 2) Testing can lead to abortions and the destruction of embryos- some people believe this in unethical as it is the destruction of potential life 3) Some people believe testing is a slippery slope, in which eventually everyone will be testing their embryos in order to pick the most “desirable”
What is genetic engineering?
The transfer of a gene from one genome to another, which gives the organism that receives the gene new and advantageous characteristics
Summarize the process of genetic engineering
1) A useful gene is cut from an organism’s genome using enzymes 2) The useful gene is replicated 3) Each copy is inserted in a vector (e.g. bacterial plasmid) 4) The vectors are then mixed with other cells (e.g. bacteria) in the hope that they are taken up by the cells 5) The cells that take up the vector will be identified and then will be able to replicate- each new cell will contain the desired gene
Why and how are vectors marked?
Because most of the vectors will not be taken up by the cells, therefore the ones that do must be able to be identified. Vectors can have a marker gene added to them to allow them to be identified
What are some of the uses of genetic engineering in medicine?
- Genetically engineering bacteria to produce human insulin has helped in the treatment of diabetes. - Researchers have also managed to transfer human genes that produce useful proteins into animals like sheep and cows
What is a use of genetic engineering in farming?
Genetically engineering crops to be herbicide resistance has allowed farmers to spray their crops with herbicides to rid of weeds, without harming the crop itself- this has increased crop yield
What is a drawback of genetic engineering of animals?
Scientists are unsure of what the consequences of modifying animals genomes will have on their health in the future
What are some drawbacks of genetic engineering of crops?
- Transferred genes may get out into the environment (e.g. if herbicide resistant genes could be picked up by weeds, creating a super-weed, resistant to herbicides) - Scientists are unsure of the adverse effects to food chains or even human health
Why is genetic engineering risky?
Because it is a new process, therefore long term testing has not been carried out on the effects of it
One long circular chromosome in the cytoplasm, Plasmids
Since prokaryotic cells do not have nuclei, where can genetic information be stored?
