Past Mock Questions Flashcards
What term is used to describe a group of organisms that produce fertile young after interbreeding?
Species
Explain the role of genes in the process of heredity
Genes are responsible for passing on characteristics/traits from parent to offspring
The formation of which type of biomolecule is controlled by genes?
Proteins
All human genes have sections of DNA whose function is unknown. What name is given to these sections?
Non-coding or junk DNA
Explain what is meant by the term DNA profilling
A method of making a unique a pattern of bands from the DNA of a person, which can then be used to compare with the DNA profile of another person
During DNA profiling the DNA is cut into fragments.
Explain how this process occurs
Through the use of restriction enzymes
Having obtained the fragment of DNA, describe the process which much occur in order to produce a DNA profile
(6)
The fragments are separated by a process called gel electrophoresis
An electric current is applied to a sugar-based gel containing the invisible DNA fragments
The small DNA fragments are separated from the larger fragments as they can travel faster through the gel
A radioactive material is added to the gel which produces a fluorescent image when combined with DNA
A photographic copy of the final pattern of DNA bands is obtained
The patterns are then compared
As part of your laboratory investigation you isolated DNA from plant tissue
Describe one step you carried out to release the DNA from the plant cell
(2)
Washing up liquid was added to the solution of water, salt and chopped up onion
The washing up liquid dissolved the cell and the nuclear membranes to release the DNA from the cell
As part of your laboratory investigation you isolated DNA from plant tissue
What was added at the end of the procedure to make the threads of DNA visible?
Freezer cold ethanol
- Not ‘ice cold’
- Freezer cold is the only acceptable answer
Give one application of DNA profiling
1/2
Used in forensic science to compare DNA samples from a crime seem with that of a suspect
This can identify if a suspect was associated with a crime
It can also be used to identify the paternity or maternity of a child
What is an allele?
Alleles are different/alternative forms of the same gene
What is the significance of an allele not being linked?
1/3
This means independent assortment can occur
There can be a greater variety of offspring
Either of a pair of alleles is equally likely to combine with either of another pair of alleles
Define the term evolution
Evolution is the way in which living things change genetically to produce new forms of life over long periods of time
Name the mechanism proposed by the Darwin-Wallace theory to explain evolution
Natural Selection
In genetics, what is meant by variation?
Variation within a species means that a group of successfully interbreeding organisms the individual members show different characteristics
Explain the link between variations and mutations
Mutations can be caused by variations and variations can be caused by mutations
What is a gene mutation?
A gene mutation is a change in a single gene
Give one example of a disorder caused by a gene mutation
1/5
Sickle-cell anaemia Colour blindness Cystic Fibrosis Albinism Haemophilia
Explain what is meant by ‘species’
A species is a group of similar organisms that are capable of naturally interbreeding
State one piece of evidence to support the Darwen-Wallace theory of natural selection
The existence of fossils
Name the type of nucleic acid that contains the sugar deoxyribose
DNA
Deoxyribose nucleic acid
Name the group of chemicals to which nitrogenous compound found in nucleic acids belong
Bases
With reference to protein synthesis explain what is meant by:
Translation
The conversion of a sequence of genetic bases on messenger RNA into a sequence of amino acids
With reference to protein synthesis explain why the process of joining amino acids together to form a protein eventually cease.
This process will continue until the stop codon is reached
Human growth hormone can now be produced by bacteria
Explain the role of genetic screening in this process
Genetic screening identifies the gene responsible for producing growth hormone
Human growth hormone can now be produced by bacteria
Explain the role played by bacteria in the production of this hormone
7
The plasmid of a bacteria cell is isolated
The plasmid is cut open using restriction enzymes
The target gene is cut from it’s chromosome using the same restriction which ensures the sections will be complementary to each other
The cut plasmid and target gene sections are combined by base pairing
The plasmid is returned to the bacterial cell
The bacterial containing the target gene are cloned
The bacterial cell reproduce and form their product (human growth hormone) - often occurs in a bioreactor
For a new species to be formed what conditions must be met by all offspring
The offspring must be fertile
Give one example of variation in humans
Different eye colour
Name one cause of different eye colour in humans
Sexual reproduction and independent assortment
Explain the term non-coding DNA
DNA that does not cause the production of a protein
Name the sugar found in DNA nucleotides
Deoxyribose
What is the function of restriction enzymes in the process of DNA profiling?
(2)
Restriction enzymes cut DNA into fragments
Each different restriction enzyme cuts DNA at specific base sequences
Write out the complementary base pair of the STR ACTT
TGAA
Name the type of bonding found between complementary base pairs
Hydrogen bonds
