3.8.4.3 Genetic fingerprinting

What is the primary biological principle that underpins genetic fingerprinting techniques?

• The uniformity of DNA sequences among individuals

• The variability of VNTRs in the genome

• The constant mutation rate of DNA

• The identical nature of mitochondrial DNA

Answer explanation

The primary principle of genetic fingerprinting is the variability of VNTRs (Variable Number Tandem Repeats) in the genome, which allows for the differentiation between individuals based on their unique DNA patterns.

Which technique is used to separate DNA fragments for analysis in genetic fingerprinting?

• Polymerase Chain Reaction (PCR)

• Gel electrophoresis

• DNA sequencing

• Cloning

Answer explanation

Gel electrophoresis is the technique used to separate DNA fragments based on size, making it essential for genetic fingerprinting analysis. PCR amplifies DNA, while DNA sequencing and cloning serve different purposes.

Why is the probability of two individuals having the same VNTRs very low?

• VNTRs are highly conserved across species

• VNTRs mutate at a high rate

• VNTRs are highly variable between individuals

• VNTRs are identical in all humans

Answer explanation

The probability of two individuals having the same VNTRs is low because VNTRs are highly variable between individuals. This variability arises from differences in the number of repeats, making it unlikely for two people to share identical VNTR patterns.

In forensic science, how is genetic fingerprinting primarily used?

• To determine the age of a suspect

• To identify individuals based on their unique DNA profiles

• To predict future criminal behaviour

• To analyse blood type

Answer explanation

Genetic fingerprinting is primarily used to identify individuals based on their unique DNA profiles, making it a crucial tool in forensic science for linking suspects to crimes.

How can genetic fingerprinting be useful in medical diagnosis?

• By determining the blood group of a patient

• By identifying genetic disorders through DNA analysis

• By predicting the lifespan of an individual

• By measuring cholesterol levels

Answer explanation

Genetic fingerprinting is crucial in medical diagnosis as it allows for the identification of genetic disorders through DNA analysis, helping to detect conditions that may not be evident through other diagnostic methods.

What role does genetic fingerprinting play in animal and plant breeding?

• It helps in determining the nutritional value of the produce

• It assists in identifying desirable genetic traits for breeding

• It predicts the growth rate of plants and animals

• It measures the water content in plants

Answer explanation

Genetic fingerprinting is crucial in breeding as it helps identify desirable genetic traits in animals and plants, allowing breeders to select individuals with the best characteristics for improved offspring.

Which of the following is a step in the process of genetic fingerprinting?

• DNA denaturation

• DNA hybridisation

• DNA amplification using PCR

• DNA methylation

Answer explanation

DNA amplification using PCR is a crucial step in genetic fingerprinting, as it increases the quantity of DNA available for analysis, allowing for more accurate results. The other options are not specific steps in this process.

What is the purpose of using gel electrophoresis in genetic fingerprinting?

• To amplify DNA sequences

• To separate DNA fragments based on size

• To sequence the entire genome

• To clone DNA fragments

Answer explanation

The purpose of using gel electrophoresis in genetic fingerprinting is to separate DNA fragments based on size. This allows for the analysis of different DNA profiles, which is essential for identification purposes.

Which of the following is NOT a field where genetic fingerprinting is commonly used?

• Forensic science

• Medical diagnosis

• Astrophysics

• Animal and plant breeding

Answer explanation

Genetic fingerprinting is widely used in forensic science, medical diagnosis, and animal and plant breeding for identification purposes. However, it is not applicable in astrophysics, which deals with celestial phenomena.

What is the significance of VNTRs in genetic fingerprinting?

• They are identical in all individuals

• They provide a unique DNA profile for each individual

• They are used to synthesise proteins

• They are responsible for coding genetic information

Answer explanation

VNTRs (Variable Number Tandem Repeats) are highly variable regions in DNA that differ among individuals, making them crucial for genetic fingerprinting. They provide a unique DNA profile for each individual, aiding in identification.