AS Level Biology Practice Test | OCR

1.The graph below shows the results of an osmosis experiment investigating the effect of changing the concentration of sodium chloride (NaCl) on mass of potatoes.

0.36 mol dm–3
0.40 mol dm–3
0.42 mol dm–3
0.62 mol dm–3

2.The reaction between carbon dioxide and water forms carbonic acid. This reaction is catalysed by the enzyme carbonic anhydrase. To catalyse this reaction, carbonic anhydrase needs a cofactor that attaches to its active site as a prosthetic group. What is the correct cofactor for carbonic anhydrase?
Ca2+
Cl –
H+
Zn2+

3.The table shows the numbers of different species of invertebrates found in four different areas in a woodland. Which row shows the area that has the greatest species richness and greatest species evenness?

A
B
C
D

4.The table shows the chemical symbols for some inorganic ions involved in biological processes. Which row gives the correct chemical symbols for all of these inorganic ions?

A
B
C
D

5. Researchers have calculated that the probability of bacterial DNA having a mutation is 1/333 in a single division.A gene has DNA that codes for amino acids and is called coding DNA. The rest of the DNA in a genome has base sequences that do not code for amino acids and is called non-coding DNA.Bacterial genome studies have shown that the average proportion of a bacterial genome that has non-coding DNA is 3/25.What is the probability of a dividing bacterium having a mutation in a gene that codes for a protein in a single division?
7351/8325
1024/8325
22/8325
1/2775

6.Restriction endonucleases are a group of enzymes that carry out hydrolysis reactions that cut long DNA molecules into shorter lengths. Which of the options describes how restriction endonucleases carry out hydrolysis reactions on a DNA molecule?
They break the glycosidic bond between a ribose and a phosphate group.
They break the hydrogen bonds between nitrogenous bases.
They break the phosphodiester bond between a deoxyribose and a phosphate group
They break the phosphodiester bond between a ribose and a phosphate group.

7. A student carried out an investigation to see the effect of changing the concentration of the enzyme maltase. They used two different maltase concentrations (concentration P and Q) to break down the disaccharide maltose for 10 minutes. The student carried out the reducing sugar test and recorded the percentage absorbance of each solution using a colorimeter. Their results are shown in the table. Which statistical test would be used to determine if there was a significant difference between the mean glucose concentration produced by maltase concentration P and maltase concentration Q?

Chi-squared test
Spearman’s rank correlation coefficient
t-test – paired
t-test – unpaired

8.International trade in parts of the rhinoceros including rhino horn has been illegal since 1977. Which organisation regulates this trade?
CBD
CITES
CSS
IUCN

9.The following passage has four key terms missing, which are names of molecules involved in protein synthesis. The enzyme .........1......... joins nucleotides together to make a copy of the gene. This makes the molecule .........2......... , which leaves through the nuclear pore to bind to an organelle that is made of protein and .........3......... . The amino acids are assembled here when .........4......... brings the specific amino acid to be joined to the polypeptide. Which row gives the correct names of these missing molecules?

A
B
C
D

10. Victoria cruziana is a tropical species of flowering plant, native to South America. Its leaves have stomata only on their upper surface and contain a large amount of aerenchyma tissue, which contains air spaces.Which group of plants does Victoria cruziana belong to?
Choose the correct answer from the options below

Epiphytes
Halophytes
Hydrophytes
Xerophytes

Score =
Correct answers: