CSEC Biology and HSB Notes

SYLLABUS OBJECTIVES  CSEC HSB [B3.1] explain the need for a transport system in the human body; [B3.2] identify the materials which need to be transported around the human body;  CSEC BIOLOGY   [B4.1] explain the need for transport systems in multicellular organisms;  [B4.2] identify the materials which need to be transported in animals & plants; 

THIS IS AN EXCERPT OF A POST FROM MY 'DELVING DEEPER' SUBSTACK BLOG. YOU CAN READ THE ORIGINAL HERE .  This post is prompted by a question in the CSEC Biology Paper 02 exam, held in January 2017.  Question 3(d) "Suggest ONE reason why haemophiliacs may be more susceptible to infectious disease."  Before we directly answer this question, let's dig into haemophilia itself.  What is Haemophilia? This is a disorder that results in the patient having a reduced ability to make blood clots. It is due to the lack of a particular clotting factor .  A (Mostly) Genetic Disorder  The missing clotting factor is a protein, and thus there is a gene for it. The disorder develops when a mutated form of the gene is present. This mutant gene provides instructions for the synthesis of a defective form of the clotting factor. The defective form does not work properly, and the development of blood clots becomes difficult.  Sex (Gender)-linked  The good news is that the...