Practice Paper 1A (HL IB Biology)

What property of fatty acids made them likely candidates for early cell membranes?

The table shows some possible units for measuring alveoli, white blood cells and cell walls.

Which of the rows show the most suitable units for measuring each of these structures?

Which of the following diagrams show bacteriophage lambda?

Which of the following presents a difficulty when applying the biological species concept?

Which of the following cannot be concluded from the cladogram below?

A team of palaeontologists discovered the remains of an insect-like organism trapped in amber, which was found in rock layers believed to be about 180 million years old. As they dug deeper into the older layers of rock, they made several further discoveries. Their findings are shown in the diagram below.

What conclusion can be drawn from the information given?

Which of the following is an important factor in mixed dipterocarp ecosystem loss in Southeast Asia?

A study was conducted to investigate the effect of saturated fat intake on the risk of developing coronary heart disease (CHD) in women.

• The study involved 20 women, aged between 35 and 50, divided into two groups (A and B) of 10.
• Group A was given a diet rich in saturated fats, while group B followed a diet low in saturated fats.
• The levels of low-density lipoprotein (LDL) in their blood was monitored over a six month period. High LDL levels has been linked to an increase in the risk of developing CHD.

At the end of the study the levels of LDL in group A was much higher than that of group B. The scientists concluded that saturated fats increases the risk of developing CHD.

Which evaluation of their conclusion would be most valid?

The following diagram shows a dipeptide with various parts of the molecule numbered (1 to 4).

Which row of the table below correctly identifies each labelled part of this dipeptide?

What is the difference between simple diffusion and facilitated diffusion?

The cube below has sides that measure 2 cm in length.

Which of the following represents the correct surface area : volume ratio of this cube?

The diagram shows a trace recorded from a spirometer.

Which label represents the tidal volume?

Certain environmental factors can affect the rate of transpiration in plants. The effect of one environmental factor on transpiration rate is shown in the graph below.

Identify the environmental factor that is having this effect on transpiration rate.

Girdling, or ring-barking, involves the removal of a strip of bark around the entire circumference of a tree trunk. This removes the outer part of the vascular bundles which results in the death of the entire tree over time.

What could be a possible explanation for this?

The aquatic crustacean the water flea (Daphnia magna, pictured below) has a heart that pumps blood-like liquid called hemolymph around its body cavity, once for every complete circuit. 

Which statement about Daphnia magna's circulatory system is correct?

The diagram below shows the sarcomere of a muscle fibre.

Which of the following statements correctly describes the events observed during a muscle contraction?

Which row correctly describes an example of an adaptation for survival in the given biome?

The Ghost Orchid (Epipogium aphyllum) is a rare plant species which lacks leaves or chlorophyll. The plant has formed a symbiotic relationship with a fungus in order to obtain the nutrition it requires. The growth of the fungus is slowed as a result of the relationship.

Which of the following rows correctly describes E.aphyllum?

A bacterial enzyme from the species Caldicoprobacter algeriensis can be immobilised onto polymethacrylate beads for the conversion of glucose into fructose in the food industry, as shown in the diagram below.

What is the name of the enzyme that is immobilised on the polymethacrylate beads?

The activity of two types of protease enzymes was measured in two different species of fish; species X and species Y. Protease enzymes are responsible for breaking down proteins into amino acids. The results of the research are shown in the graph.

The unit U denotes the enzyme required for the production of 1 μmol of product per minute. The bars represent the standard deviation.

Which statement about protease enzymes is correct?

The diagram below shows a simplified Krebs cycle.

How many times does decarboxylation occur during the Krebs cycle?

A student designed the following experimental set-up to measure the effect of light intensity on the rate of photosynthesis. The experiment was repeated three times.

The results were inconsistent, how could the experimental set-up be improved?

Which process is not part of the light-independent reaction of photosynthesis?

Which features are characteristic of transmembrane receptor proteins?

The diagram below shows a sodium-potassium pump within the axon membrane of a neurone.

What is the role of active transport in the transmission of nerve impulses by neurones?

The diagram below shows the left to right transmission of an action potential in a myelinated axon by saltatory conduction.

Which of the following rows correctly identifies I - IV?

A pot plant falls over and after a few days shows the following growth pattern.

Which of the following is the most accurate explanation for the growth shown at each of the labels on the diagram?

Some bacteria develop resistance to antibiotics by forming biofilms, which are large colonies of bacteria clumped together.

Which statement best explains how forming a biofilm might give a bacterial species resistance to antibiotics?

What can be concluded about levels of atmospheric carbon dioxide from the graph shown?

A DNA profile was created for two genes in three individuals (A, B, and C).

Which of the following statements, relating to the images provided, are correct?

The relationship between DNA fragment length and distance moved through the gel is linear.

Fragment length is determined by the number of repeated DNA sequences in a sample.

There is a percentage increase of 50 % between the distance moved by fragment Y and that moved by fragment X.

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

What is the maximum number of amino acids that could be coded for by this DNA?

The nucleotide base sequence and the associated sequence of four amino acids can be seen below:

AGG   ACA   CCT   GGA

Serine   Tyrosine   Glycine   Proline

The table shows the mRNA codons and their associated amino acids.

A single mutation occurred in the original base sequence of the DNA which resulted in only one amino acid from the sequence being produced.

Which of the following would represent the correct nucleotide base sequence which was found in the DNA after the mutation occurred?

In humans, during periods of hypoxia (low oxygen in tissues) the transcription factor HIF (Hypoxia-Inducible Factor) binds to the Hypoxia Response Element (HRE) sequence and increases transcription of the EPO gene. This stimulates the production of red blood cells. The diagram shows the EPO gene and regulatory elements.                                                                                  

Which kind of regulatory elements are HIF and HRE?

An experiment to calculate the water potential of potato cells was performed using the following protocol:

1. Dice potato into 1cm³ cubes.
2. Add potato cubes to 6 test tubes, each containing solution with a different sucrose concentration.
3. Wait 12 hours.
4. Weigh the cubes from each test tube and plot a graph. 

The mean mass of the potato cubes was 2.50 g before being added to the solution, and the graph shows the masses of the potato cubes after the experiment.

Which concentration of sucrose matches the water potential of the potato cells?

Two linked genes are denoted by the dominant alleles G and H. Their recessive counterparts are g and h respectively.

Which way of writing the allele combinations on their chromosomes best displays the linkage between the two genes?

Nephrogenic syndrome of inappropriate antidiuresis (NSIAD) is a rare condition that can be caused by a gain-of-function mutation in the gene that codes for ADH receptor proteins. This means that sufferers of the condition will produce more ADH receptors or will produce ADH receptors that are more sensitive than normal.

Which of the following will not be true for sufferers of NSIAD?

The three graphs below show how the allele frequencies of two alleles in three different populations changed over several generations.

Which of the graphs show changes in allele frequency that suggest that evolution is taking place?

Which of the statements about ecological succession is correct?

The graph below shows the differences between the radiation reaching the earth from the sun and the radiation re-emitted by the earth.

How does this radiation cause the greenhouse effect?