A gene of a particular organism contains 29% thymine (T). Which answer would best represent the percentage distribution of the other nucleotides in this gene?

Which of these are simple sugars?

The graph shows the effect of carbon dioxide (CO2) concentration on the rate of photosynthesis. What could be limiting the rate of photosynthesis at points X and Y?

In the manufacture of insulin, a human gene is inserted into which of these?

Which of the following produces bile?

Name process A and cell B.

Which of these are examples of continuous variations?

Identical pieces of potato are placed in sucrose solutions of different concentrations. After three hours, the mass of each potato piece is measured.

Which graph shows the results of this experiment?

Cubes of hard-boiled egg white are placed in test-tubes containing $5\ cm^3$  of water. Other substances are added to each tube as shown in the chart. The tubes were left for eight hours and then tested for amino acids. 

The diagram illustrates a simple potometer which measures water uptake in plants.

Which combination of conditions would result in the fastest uptake of water?

The diagram shows the condition of a stoma at different times of the day.

Which of the following shows the most probable times at which the stoma is being observed?

Which of the following occurs in meiosis but not in mitosis?

whats 1+1

A person with Down's syndrome is born with 47 chromosomes in each cell, instead of 46.

What could cause this?

A mixture of food gives the following results on testing:

a purple colour in the biuret test,

a blue colour when heated with Benedict's solution,

a yellow colour with iodine,

a white emulsion with ethanol.

What does the mixture contain?

Protease enzyme breaks down proteins to amino acids.

In the 'lock and key' hypothesis, what is the lock and key?

The diagram shows a short section of a molecule of DNA.

Which of the following sets of labels is correct?

The lifespan of re blood cells is approximately 120 days. New red blood cells are released into the bloodstream from the bone marrow. Unlike typical cells in the body, they do not reproduce by mitosis.

What is the likely explanation for this?

Which of the following would not be an expected consequence of the removal of the pancreas?

The diagram represents the nucleus of a cell (where 2n = 4) in late prophase of meiosis.

Which diagram represents a cell of the same species in anaphase II of meiosis?

What happens to the excess glucose in the liver?

I. It is broken down to release energy.

II. It is broken down into fats.

III. It is deaminated to produce urea.

IV. It is stored as glycogen.

The cell wall of a plant cell is removed using an enzyme. What would happen if this cell is then placed in distilled water?

The diagram represents one pair of homologous chromosomes during meiosis. Crossing over occurs and random segregation takes place.

What are the genotypes of the resulting gametes?

The colour of the fruit of tomato plants is determined by alleles of the same gene. A tomato plant with red fruit was crossed with a tomato plant with yellow fruit. Of the offspring, 26 plants had red fruit and 24 had yellow fruit. Three explanations were suggested.

1. Both parents were homozygous.

2. One parent had 2 recessive alleles.

3. One parent was heterozygous.

Which of the explanation/s is/are correct?

Which statement about chromosomes is correct?

A series of cell processes are listed below.

1. mineral ions entering root hair cells

2. glucose uptake by villus cells

3. water entering root hair cells

Which of these involve active transport?

what's your name lol