Mid term corrections

Question 1

DNA in bacteria is different from DNA in the nucleus in terms of: ???/?/?//?/

Answer 1

Introns are present in nuclear DNA but absent in bacterial DNA, bacterial DNA is circular and nuclear DNA is linear,

Question 2

Describe how the secondary structure of a polypeptide is produced by bonds between amino acids?

Answer 2

Hydrogen bonds between the NH (group of one amino acid) and the C=O of another which form beta pleated sheets and alpha helices.

Question 3

Suggest a method to measure the quantity of precipitate produced without using a colorimeter?

Answer 3

Filter and dry the precipitate then find the mass

Question 4

Colours after benedict’s and maltase are added to glucose and maltose separate solutions.

Answer 4

Benedict’s added to glucose will test red, maltase added to glucose will still test the same colour of red as there is still just glucose.

Benedict’s added to maltose will test red, maltase added to the maltose will test darker red because the maltose has been broken down further.

Question 5

Measure 15cm cubed of solution
Measuring cylinder gives a volume with an uncertainty of +/-1.

Measure 5cm cubed Benedict’s solution
Syringe has a volume with an uncertainty of =/-0.5.

Mix the two solutions.
Calculate the percentage error of measurement used to make the 20cm cubed of solution.

Answer 5

(1.0+0.5/20)x100

Question 6

Name the enzyme used in DNA replication after the scientist got the DNA to be single stranded?

Answer 6

DNA Polymerase

Question 7

Use your knowledge of semi-conservative DNA replication to suggest the role of the single stranded DNA fragments.

Answer 7

Acts as a template, determining the sequence of nucleotides.

Question 8

Use your knowledge of semi-conservative DNA replication to suggest the role of the DNA nucleotides.

Answer 8

Forms complimentary base pairs

Question 9

Explain why something REALLY REALLY REALLY small may not be seen with an optical microscope.

Answer 9

Light has a longer wavelength so lower resolution