AQA A Level Biology复习笔记4.1.4 Genes
The Definition of a Gene A gene is a base sequence of DNA that codes for the amino acid sequence of a polypeptide or a functional RNA molecule Functional RNA molecules are required for prote...
AQA A Level Biology复习笔记4.1.3 Mitochondria & Chloroplast DNA
Mitochondria & Chloroplast DNA Mitochondria A single mitochondrion is shown – the inner membrane has protein complexes vital for the later stages of aerobic respiration embedded within i...
AQA A Level Biology复习笔记4.1.2 Eukaryotic DNA
Chromosome Structure Chromosomes are made of one very long, condensed DNA molecule associated with proteins (in eukaryotic cells) The main proteins present are the large positively charged g...
AQA A Level Biology复习笔记3.6.8 Tracer & Ringing Experiments
Tracer & Ringing Experiments Tracer and ringing experiments have been used to investigate mass transport in plants It is described as a ringing experiment because it involves the removal...
AQA A Level Biology复习笔记3.6.7 Data on the Mass Flow Hypothesis
Evaluating Data Linked to Mass Flow Hypothesis The mechanism of transport that occurs within the phloem is still debated by scientists The mass flow hypothesis suggests that there is a trans...
AQA A Level Biology复习笔记3.6.6 The Mass Flow Hypothesis
Phloem: Mass Flow The Mass Flow Hypothesis was the model initially used to explain the movement of assimilates in the phloem tissue The mass flow hypothesis was modelled by Ernst Münch in 19...
AQA A Level Biology复习笔记3.6.5 The Sucrose Loading Mechanism
The Sucrose Loading Mechanism Assimilates such as sucrose are transported from source to sink through the phloem sieve tubes Carbohydrates are generally transported in plants in the form of ...
AQA A Level Biology复习笔记3.6.4 Movement in the Phloem
Movement in the Phloem Although translocation could refer to the transport of substances in the xylem and phloem, as it means ‘moving from one place to another,’ it is more commonly connecte...
AQA A Level Biology复习笔记3.6.3 Potometer Practical
Apparatus & Techniques: Using a Potometer Air movement, humidity, temperature and light intensity all have an effect on the rate at which transpiration occurs The table below explains ho...
