uses and dna profiling Flashcards
How has gene sequencing allowed for genome-wide comparisons between individuals and species? (5)
Computational biology and bioinformatics are used for genome comparisons;
It helps predict phenotypes from genotypes;
Computerised comparisons can detect mutations linked to diseases;
Genome comparisons help determine evolutionary relationships between species;
Closely-related species share more DNA and have diverged more recently
How has gene sequencing allowed for the prediction of amino acid sequences in polypeptides? (3)
Sequencing a gene allows prediction of the sequence of amino acids that the gene codes for;
This helps predict the primary structure of a polypeptide;
It enables synthetic biology, allowing the creation of biological molecules from scratch
How has gene sequencing contributed to the development of synthetic biology? (3)
Involves building biological systems from artificially-made molecules to test their functions;
Helps redesign biological systems for better performance;
Synthetic biology enables the design of new biological systems that don’t exist naturally, like creating new drugs
What role do non-coding sequences play in DNA profiling? (4)
Some parts of the genome contain repeated non-coding base sequences;
The number of repeats at specific loci differs between individuals;
DNA profiling analyzes these repeats using electrophoresis;
The probability of two individuals having the same DNA profile is very low due to the unique number of repeats
What is the first step in carrying out DNA profiling on a sample? (1)
DNA is isolated from the sample
How are multiple copies of DNA made in DNA profiling? (2)
PCR;
Used to make many copies of the DNA region containing sequence repeats
What is the role of restriction endonucleases in DNA profiling? (1)
Cut the DNA near the repeated regions
How are the DNA fragments separated in DNA profiling? (1)
By electrophoresis
What happens after electrophoresis in DNA profiling? (2)
Gel is immersed in alkali; To separate double strands into single strands
What process transfers DNA bands onto a membrane? (2)
Southern blotting; Which transfers DNA bands onto a membrane
What is hybridisation in DNA profiling? (1)
When radioactive or fluorescent probes bind to the repeated sequences
What happens to excess probe in DNA profiling? (1)
Excess probe is washed off
How are the DNA fragment positions revealed in DNA profiling? (2)
X-ray film or UV light detects the probes; Revealing unique DNA fragment positions
What is a DNA probe? (4)
A short single-stranded section of DNA (~20 bases long);
Binds to a complementary DNA sequence;
Radioactively or fluorescently labelled to aid detection;
Probes are 20 nucleotides long to ensure specificity
What are the uses of genetic fingerprinting? (4)
Forensic science: links a person to a crime scene by comparing DNA profiles.;
Preventing inbreeding: identifies relatedness in plants/animals to avoid mating closely related individuals;
Diagnosing genetic disorders: determines risk or presence of disorders by comparing DNA profiles.;
Preimplantation genetic haplotyping: screens embryos for genetic disorders before implantation in IVF
