A Level Ms Pur

The structure of cellulose is held together by which type of bond?
1. ionic bonds

2. 2. glycosidic bonds

3. 3. hydrogen bonds

• 1, 2, and 3

• 1 and 2 only

• 2 and 3 only

• 1 and 3 only

two biological molecules are shown in the diagram above. Which row of the table correctly

• molecule 1 has 3 fatty acid chains and fatty acid chains are all saturated molecule 3

• molecule 1: has 2 ester bonds and a phosphate group, molecule 2: has 3 phosphodietester bonds

• molecule 1: has 3 saturated fatty acid chains, molecule 2: has 1 unsaturated fatty acid chain

• both molecule is polar

The effect of different colours of light on the growth of Arabidopsis thaliana (thale cress) seedlings was studied.

Three different colous of light were tested and measurements of seedling height, shoot length, and biomass were taken. The results of the study shown in Table 1 below.

State what can be concluded about the effect of different coloys of light on the growth of Arabidopsis thaliana from the data shown.

A team of researchers investigated the effect of changing the carbon dioxide concentration on the levels of glycerate-3-phosphate (GP) and ribulose biphosphate (RuBP) in photosynthesising cells.

Table 1 shows the results obtained when the carbon dioxide concentration was reduced.

Explain the results for RuBP and GP at 0.003% carbon dioxide concentration.

A piece of DNA was analysed to find the number of nucleotides bases in each of the polynucleotide strands. Some of the results are shown below:

How many maximum number of amino acids that could be coded for by this DNA?

• 22

• 29

• 34

• 40

Ribosomes exist as two separates subunits that join together during protein synthesis. What do these subunit consists of?

• rRNA and protein

• rRNA and lipid

• rRNA and mRNA

• rRNA and tRNA

DNA and RNA are nucleic acids. Explain wht RNA can be describes as a polymer and as a macromolecule.

In fruit flies (Drosophila melanogaster) wing length and body coloyr are each controlled by a single gene with two alleles. Allele L forlong wings is dominant over allele l for vestigial wings, while allele G for grey body colour is dominant over allele g coding for ebony body coloyr.

Two homozygous fruit flies were crossed, one had a grey body colour and long wings while the other had an ebony body colour and vesitigal wings.

State the numer of offspring that would display a grey body colour and vestigial wings if 400 offspring were produced from this cross and explain your answer