A-level Biology CIE

State the two ways in which ATP are produced.

1. Transfer of phosphate in substrate-linked reactions

2. Chemiosmosis in the membranes of the mitochondria and chloroplasts

Respiratory quotient definition.

The ratio of the number of molecules of carbon dioxide produced to the number of molecules of oxygen taken in, as a result of respiration.

Where does link reaction occur?

mitochondrial matrix

Where does glycolysis occur?

cytoplasm

Where does Krebs cycle occur?

mitochondrial matrix

Where does oxidative phosphorylation occur?

inner mitochondrial membrane

Site of the light-dependent stage of photosynthesis.

thylakoids (thylakoid membranes and thylakoid spaces) which occur in stacks called grana

Site of the light-independent stage of photosynthesis.

stroma

What two reaction chains occur during the light-dependent stage of photosynthesis?

cyclic photophosphorylation and non-cyclic photophosphorylation

What molecules is the Calvin cycle intermediate GP (glycerate 3-phosphate) used to produce?

amino acids

What molecules is the Calvin cycle intermediate TP (triose phosphate) used to produce?

amino acids, lipids, carbohydrates

What are the limiting factors of photosynthesis?

light intensity, temperature, carbon dioxide concentration

How is urea produced?

From the deamination of excess amino acids.

Where is urea produced?

In the liver.

Ways in which rice is adapted to grow with its roots submerged in water.

1. development of aerenchyma in roots

2. ethanol fermentation in roots

3. faster growth of stems

What are transcription factors?

Proteins that bind to DNA and are involved in the control of gene expression in eukaryotes by decreasing or increasing the rate of transcription.

Conditions where the Hardy-Weinberg principle can be applied.

1. No natural selection

2. Random mating

3. No mutations

4. No gene flow

5. A large population

Define recombinant DNA

DNA that has been artificially created by combining DNA fragments from different sources.

Are Archaea and Bacteria prokaryotes or eukaryotes?

Prokaryotes

What are the differences between Archaea and Bacteria?

Membrane lipids: branched hydrocarbons ——- straight-chain fatty acids

ribosomal RNA: contains histones —— unique to bacteria

Composition of cell wall: no peptidoglycan —— peptidoglycan

Define ecosystem

A community of interacting organisms and their physical environment.

Define niche.

The role a species plays within its ecosystem, including its habitat, feeding habits and interactions with other species.

What is the significance of different values of D, the Simpson’s Index?

Larger D = larger biodiversity