Photo AI
Write notes on three of the following topics: (i) Vaccination - Leaving Cert Biology - Question (b) - 2019
Question (b)
Write notes on three of the following topics: (i) Vaccination. (ii) Antibiotic resistance in bacteria. (iii) The mechanism of phototropism or of geotropism in pla... show full transcript
Worked Solution & Example Answer:Write notes on three of the following topics: (i) Vaccination - Leaving Cert Biology - Question (b) - 2019
Step 1
(i) Vaccination.
Answer
Vaccination involves the introduction of a non-harmful or weakened form of a pathogen (or antigen) into the body. This can stimulate the immune system to produce antibodies, leading to both active immunity and the formation of memory cells (either T cells or B cells). As a result, if the body encounters the actual pathogen in the future, these memory cells can prevent the spread of disease.
Step 2
(ii) Antibiotic resistance in bacteria.
Answer
Antibiotic resistance occurs when bacteria evolve in a way that makes them unaffected by antibiotics. This can result from the misuse of antibiotics or the failure to complete a prescribed antibiotic course. Pathogens may acquire resistance through plasmids carrying resistant genes. Some bacteria may also slow down growth or be killed by certain antibiotics, further complicating treatment options.
Step 3
(v) The sounds created during the cardiac cycle.
Answer
The cardiac cycle produces two main sounds, known as 'lub' and 'dub'. The 'lub' sound occurs when the atrioventricular (AV) valves close, marking the beginning of ventricular contraction. The 'dub' sound follows the closure of the semilunar valves, indicating the end of ventricular contraction and the start of relaxation. These sounds are crucial for monitoring heart function.