What is meant by a genome?

Chromatin immunoprecipitation is one method to determine where a transcription factor binds to DNA. The principle behind this procedure is shown in Figure 8.

Explain why the antibody binds to the transcription factor.

Use Figure 8 to explain what 'precipitated DNA' consists of.

Soybeans are used in a number of processed foods. However, soybeans contain a protein known as P34 that causes an allergic response in some people. Scientists have created transgenic soybeans that produce single-stranded cDNA, which prevents transcription of the P34 gene. They used recombinant plasmids as vectors to transform soybean cells. After they had screened these cells for production of the P34 protein, they cultured the transformed cells to form soybean plants.

Suggest how single-stranded cDNA could prevent transcription of the P34 gene.

Describe the roles of two named types of enzymes used to insert DNA fragments into plasmids.

Type of enzyme

Role

Type of enzyme

Role

The soybean cells were screened for the presence of the P34 protein. This process involved the use of gel electrophoresis to separate proteins extracted from soybean cells.

Suggest two features of the structure of different proteins that enable them to be separated by gel electrophoresis.

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