Take this Quiz: A-Level Biology: Gene Expression and Technology | Zestly

Question 1

Which of the following best describes the molecular mechanism by which oestrogen regulates gene expression?

Accepted Answer

Oestrogen binds to a receptor protein, forming a complex that enters the nucleus and binds to specific promoter regions.

Question 2

In the context of stem cell potency, which of the following statements are accurate?

Accepted Answer

Pluripotent stem cells can differentiate into almost any cell type but cannot form an entire organism.

Question 3

During the polymerase chain reaction (PCR), what is the specific function of the temperature cycle at approximately 55-65°C?

Accepted Answer

To allow primers to anneal to the complementary sequences on the single-stranded DNA.

Question 4

Which of the following are true regarding the roles of enzymes in recombinant DNA technology?

Answer

Restriction endonucleases cut DNA at specific palindromic recognition sequences.

Answer

DNA ligase is used to amplify the target gene sequence during the cloning process.

Answer

Restriction enzymes always produce blunt ends when they cleave DNA molecules.

Answer

DNA ligase catalyzes the formation of phosphodiester bonds between DNA fragments.

Answer

Reverse transcriptase is used to cut the vector DNA to allow for insertion.

Question 5

How does the development of malignant tumours differ from benign tumours in terms of cellular behavior?

Answer

Malignant tumours grow slowly and remain encapsulated within a fibrous tissue.

Answer

Benign tumours are characterized by metastasis, where cells break away and form secondary tumours.

Answer

Malignant tumours have the ability to invade surrounding tissues and metastasize via the blood or lymphatic system.

Answer

Benign tumours show uncontrolled cell division due to the complete loss of tumour suppressor gene function.