Genetics, part 1

Using the DNA fingerprint shown in the picture, which suspect committed the crime?

• suspect 1

• suspect 2

• suspect 3

• none of them! need new suspects!

The frozen remains of a mammoth were found in recent times in Siberia. Scientists were able to extract a small amount of DNA, but need more in order to try to clone the mammoth. In order to clone small amounts of DNA, what of the following techniques needs to be used in order to generate larger quantities of the DNA?

• polymerase chain reaction (PCR)

• DNA fingerprinting

• gene splicing

• gel electrophoresis

Refer to an experiment that was performed to separate DNA fragments from four samples radioactively labeled with 32P. The fragments were separated by gel electrophoresis. The visualized bands are illustrated in the diagram above.

The electrophoretic separation of the pieces of DNA in each of the four samples was achieved because of differential migration of the DNA fragments in an electric field. This differential migration was caused by the _________.

• relative amounts of radioactivity in the DNA

• number of cleavage points per fragment

• size of each fragment

• overall positive charge of each fragment

Assume that you are the president of a plant biotechnology company and you want to offer your customers a new variety of apples that tastes great, lasts longer on the shelf, and is less susceptible to insect damage. Which method will be the most precise and produce plants with the desired characteristics quicker?

• traditional plant breeding

• genetic modification through genetic engineering

• neither technique; research efforts have not focused on creating organisms with specific combinations of characteristics

The diagram represents a technique used in some molecular biology laboratories. This technique is a type of ___.

• chromatography

• gel electrophoresis

• direct harvesting

• recombinant DNA technology

An application of using DNA technology to help environmental scientists would be _____.

• use PCR to analyze DNA at a crime scene

• make transgenic bacteria that can be used to clean up oil spills more quickly than do the natural

• clone the gene for human growth hormone to treat pituitary dwarfism

• create a flower that glows in the dark

After conducting several tests, a scientist determines that the nucleic acid sample he is studying has the following characteristics:

• Contains nucleotides linked in a chain

• Contains 4 nitrogen bases

• Made of single strand

• Uracil is present

What is the BEST conclusion the scientist can make based on the observations?

• The nucleic acid is DNA

• The nucleic acid is RNA

• The nucleic acid is a protein

• One cannot determine what type of nucleic acid the scientists is studying. More tests would need to be run to gather more data.

What nitrogen base always pairs with adenine in RNA?

• thymine

• cytosine

• guanine

• uracil

What nitrogen base always pairs with adenine in DNA?

• thymine

• cytosine

• guanine

• uracil

What base is found in RNA but not DNA?

• adenine

• thymine

• cytosine

• uracil