Studied by 2 people
Why do humans, animals and plants look like their parents?
They inherit genetic information from them
Where is genetic information stored?
The genome
Which cells don’t contain a complete copy of the genome?
Gametes
What sort of organisms have a genome?
All living organisms
How does the environment interact with your genome?
The environment can affect cell molecules on the cell surface which leads to changes how the information in the genome is used. This can affect you features.
Where is the genetic material found in animals and humans?
The nucleus
Are bacteria prokaryotic organisms or eukaryotic organisms?
Prokaryotic organisms
Where is genetic material found in prokaryotic materials?
Plasmids
Where is genetic material found in eukaryotic materials?
The nucleus
How many chromosomes are in the nucleus of the human body?
46
How many chromosome pairs are in the nucleus of the human body?
23
What is a long molecule of DNA?
Chromosomes
What year was the structure of DNA discovered?
1953
Who discovered the structure of DNA?
James Watson and Francis Crick
How did people discover the structure of DNA?
They saw a photo of DNA that was taken using x-rays.
What is a double helix?
Two strands that are twisted together
What is a nucleotide?
A nucleotide is the basic building block of nucleic acids (RNA and DNA). It has a phosphate, a sugar and a base
What is a polymer?
A polymer is a long chain of molecules made from lots of small molecules that join together.
What is a genome?
The complete set of genetic material in an organism.
What are 4 health and safety rules when using a light microscope?
Never look down a microscope without a slide on the stage.
Always start with the objective lens near the slide and move it away so that you do not smash the slide.
Never work unsupervised.
Wear eye protection
What is a gene?
A region of DNA
how many genes are in the human genome?
around 20000
what percentage of the genome do genes make up?
about 1.5%
What is gene expression?
it controls when the information in genes is used to make proteins
What is the study of structure and functions of genomes called?
genomics
what are the two types of proteins?
structural, functional
What are proteins made of?
Amino acids
What gene can cause a disease called phenylketonuria
PAH
What enzyme can’t a person with phenylketonuria break down?
phenylalanine
Where is phenylalanine found?
food and artificial sweeteners
What is a genetic variant?
A different version of the gene
What is a genotype?
the combination of alleles
What is a phenotype?
the observable characteristic
What is smaller: nucleotide or nucleus?
nucleotide
WHat is smaller: gene or chromomsome?
gene
What is smaller: nucleotide or chromosone?
nucleotide
What is smaller: nucleus or gene?
gene
What is the difference between your genotype and your phenotype?
The genotype is the genetic code, while the phenotype is how those genes are expressed and observed. The phenotype is influenced by the genotype and environmental factors.
Describe the relationship between proteins and amino acids
Proteins are made of long chains of amino acids. The amino acids link together in specific sequences to make proteins. amino acids are joined by covalent bonds called peptide bonds which form a polypeptide chain. A protein can consist of one or more polypeptide chains folded into 3d structures. The order of amino acids in a protein is determined by the genetic code in DNA. amino acids have different properties and decide how proteins interact with each other and their environment.
How are babies tested for PKU?
Babies are tested for PKU by the heel prick test which tests their blood.
How is brain damage prevented in a baby who has PKU?
Babies with the disease are put on a diet without phenylalanine so their brains will develop normally.
What is an allele?
Alleles. are different versions of the same gene
What base does adenine pair with?
thymine
What base does thymine pair with?
adenine
What base does guanine pair with?
cytosine
What base does cytosine pair with?
guanine
What is base pairing?
A base pair consists of two complementary DNA nucleotide bases that pair together to form a “rung of the DNA ladder.”
what are the steps in protein synthesis?
Weak bonds between the paired bases are broken “unzipping” the DNA and separating the two strands. This exposes the bases.
Immediately, free nucleotides in the cell pair up with the exposed bases, forming new strands.
Because a always pairs with T and G always pairs with C, the two new strands are identical to the originals.
Where is the information to make protein stored?
Genetic code
How many amino acids are there?
around 20
What does the order of amino acids affect?
the way the polymer folds to form the 3d shape of protein
What is triplet code?
three bases for one amino acid
Where does protein synthesis occur?
ribosomes
Where do ribosomes get instructions for making proteins from?
mRNA
What is the difference between DNA and mRNA?
mRNA only has 1 strand
mRNA doesn’t have thymine, instead it has uracil
What is the 1st step of making a protein?
The gene unzips and mRNA bases pair with DNA bases to form a strand of mRNA
What is the 2nd step of making a protein?
the mRNA moves out of the nucleus to a ribosome in the cytoplasm.
What is the 3rd step of making a protein?
The ribosome attaches to one end of the mRNA. as it moves along mRNA the ribosome reads the genetic code so that the amino acids can join the mRNA in the correct order.
What is the 4th step of making a protein?
The ribosome releases the protein into the cytoplasm and starts to make another one.
Why can new strands of DNA can be made alongside the unzipped ones?
New strands of DNA can be made alongside the unzipped ones because the bases pair up specifically since A only pairs up with T and C only pairs up with G. This allows the mRNA to add bases that match the original ones.
Why are the new strands of DNA are identical to the original ones.
base pairing means that the sequences end up in the right order
How many different amino acids do cells use to make proteins?
three
How many different codes are there in the table of mRNA triplet codes?
48
If a protein molecule is a sequence of 141 amino acids, how many mRNA bases are needed to code for it?
forty seven
Suggest how having lots of ribosomes can speed up making protein
Having lots of ribosomes in the cytoplasm speeds up protein production because multiple ribosomes can work simultaneously to translate different mRNA molecules. Each ribosome reads an mRNA strand and assembles a protein, so the more ribosomes there are, the more proteins can be made at the same time. This increases the overall rate of protein synthesis.
What is mutation?
change in the sequence of bases
What is point mutation?
When a nucleotide is substituted for another
What is an insertion mutation?
changes the way the basses are divided into triplets by adding a base
What is a deletion mutation?
When a base is deleted
Do mutations only occur in genes?
No they can happen in other parts of the genome as well or it could affect gene expression
What is the male gamate?
It is the sperm cell
What is the female gamate?
It is the egg cell
How many chromosomes do gametes have?
23
When the sperm cell fertilises the egg how many chromosomes do they have?
46
What is the name of the gene controlling earwax?
ABC11
What two genetic variants can earwax have?
wet ear wax, dry ear wax
What mutation is the difference between the two variants of earwax?
point mutation
Which variant of ear wax dominant?
wet ear wax
What does homozygous mean?
two alleles that are the same
What does heterozygous mean?
two different alleles
