Biology EE Topic Ideas + examples

You still can’t decide on the subject of your Biology extended essay? The syllabus allows for a variety of topics. It is best to link the essay with the subjects that you found interesting during the course. Below you can find a list of 15 topics with examples for inspiration. 

 Biology EE ideas 

1. Fitness levels: By choosing this investigation you would evaluate the impact of dancing various styles like Cha Cha, Viennese Waltz, and Modern Contemporary on fitness levels, measured by oxygen consumption and maximum heart rate. The choice of dance styles represents different intensities and muscle groups, aiming to understand their varying effects on aerobic respiration and overall cardiovascular health. This inquiry aims to deepen understanding of how dancing influences the body's physiological responses.
   
    

2. Cone Repair technique: Through this topic, you would explore the physiological intricacies of Ebstein's anomaly (a rare heart defect affecting the tricuspid valve) and the technological advancements in treating heart conditions, particularly through surgical innovations like cone repair. The cone repair technique, though promising, is still relatively novel, with research suggesting high success rates but limited application due to its novelty. Through secondary data analysis, this essay aims to evaluate the effectiveness of cone repair compared to traditional surgical methods (Valve Replacement and Maze Procedure), considering success rates, side effects, and ethical implications.
   
    

3. Antibacterial properties of garlic: The research aims to investigate the effects of garlic juice prepared in various ways on the growth of Escherichia coli. Garlic, known for its therapeutic and culinary uses, contains allicin, a compound crucial for its properties. Different preparations of garlic (fresh, raw, crushed one day prior, and fermented in brine) may alter allicin content, potentially affecting its antimicrobial efficacy. Understanding the synthesis and mechanism of action of allicin is essential, as it is primarily responsible for garlic's antimicrobial properties, diffusing across cell membranes and reacting with cysteine residues within bacterial cells.
   
    

4. Pharmaceuticals as contaminants in aquatic plants and ecosystems: The presence of pharmaceutical contaminants in waterways, originating from various sources including improper drug disposal and pharmaceutical manufacturing, poses significant risks to human health and aquatic ecosystems. These contaminants can lead to antibiotic resistance, developmental problems, and other adverse health effects in humans and wildlife. In this topic, you could find out how the presence of Acetaminophen (Tylenol), Polymixin B (Polysporin), and diphenhydramine hydrochloride (Benadryl) in the growth medium of Cotoneaster acutifolius affects the average change in leaf length in different concentrations. 
    
    

5. Thermoreception and Sleep: Previous research has extensively explored the impact of sleep on neural processes, however, little investigation has been conducted on how sleep affects thermoreception, the ability to sense temperature changes. Understanding this relationship may have implications for various fields including physiology, neurobiology, sports, and public safety, potentially revealing how sleep deprivation affects activities like walking. By engaging in this topic you could research how the number of errors made by participants when attempting to distinguish between the temperature of two different water baths is influenced by the hours slept within a 24-hour period. 
   
    

6. Blood Pressure and Alzheimer’s Disease: With an aging population globally, there's an increasing demand for additional healthcare. Alzheimer's disease severely affects both physical health and societal engagement. Investigating how cerebrovascular factors, particularly blood pressure, influence Alzheimer's development is crucial, given the brain's dependency on efficient blood circulation. Despite varying study results, understanding the relationship between blood pressure and Alzheimer's is vital for determining preventive measures and pharmaceutical effectiveness. This study aims to synthesize existing data to ascertain the extent of the association between blood pressure and Alzheimer's disease in individuals over 50 years old.
   
    

7. Monogenetic obesity: Obesity has surged globally posing significant health and social challenges. Weight bias often leads to negative stereotypes and may contribute to the development of eating disorders. Additionally, obesity increases the risk of serious health conditions such as diabetes and cardiovascular disease. Genetic factors, particularly deletion frameshift mutations affecting the leptin-melanocortin pathway, play a role in monogenetic obesity disorders. Understanding these genetic abnormalities could lead to improved therapeutic treatments and societal well-being.
    

   Check out our free Biology EE exemplars

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   Grade received: A

   To what extent do different honey brands affect their antibacterial activity to test their hydrogen peroxide content using permanganometric titration?

   

   Grade received: A

   “Is the cone repair a suitable approach for severe forms of Ebstein anomaly?”

   

   Grade received: A

   What is the effect of different light combinations on the movement of semiaquatic turtles, red-eared slider (Trachemys scripta elegans) with respect to the position of the light sources?

   

   View hundreds of other Biology EE exemplars on Clastify

   Click to view exemplars

   

   Grade received: B

   To what extent does high intensity interval training (HIIT) effect the maximum oxygen uptake (VO2max) in sedentary populations?

   

   Grade received: A

   How do different concentrations of two cytokinin hormones: Kinetin (0.5, 1 and 1.5 mg/L) and 6-Benzylaminopurine (1.5, 2 and 2.5 mg / L) affect the growth of Lactuca sativa, measured by height, number of leaves and dry mass, separately and combined over 5 weeks?

   

   Grade received: A

   To what extent is blood pressure related to the development of Alzheimer’s Disease in people in age above 50?

   

   Grade received: A

   To what extent do phytochemicals such as resveratrol, glyceollin and epigallocatechin-3-gallate (EGCG) possess comparable antibacterial effects against Staphylococcus aureus bacteria to a non-prescription otitis externa (OE) treatments such as Ciprofloxacin using Bacillus subtilis as a prokaryotic model organism?

   

   View hundreds of other Biology EE exemplars on Clastify

   Click to view exemplars

   

   Grade received: D

   What is the effect of seawater mixture (0%, 5%, 10%) on the germination of black chickpeas (Cicer arietinum), Green Gram (Vigna radiata) and Fenugreek (Trigonella foenum-graecum) for 5 days and their subsequent growth when watered using tap water for 10 days where growth was measured by plant height (±0.05 cm) and dry mass (±0.001 g)?

   

   Grade received: A

   To what extent does the presence of acetaminophen (Tylenol), Polymixin B (Polysporin), and diphenhydramine hydrochloride (Benadryl) in the growth medium of Cotoneaster acutifolius affect the average change in leaf length over a period of 15 days in five different concentrations?

   

   Grade received: A

   To what extent do cosmetic procedures like bleaching and heat straightening affect the tensile strength of Homo sapiens hair?

   

   Grade received: A

   To what extent do different honey brands affect their antibacterial activity to test their hydrogen peroxide content using permanganometric titration?

   

   Grade received: A

   “Is the cone repair a suitable approach for severe forms of Ebstein anomaly?”

   

   Grade received: A

   What is the effect of different light combinations on the movement of semiaquatic turtles, red-eared slider (Trachemys scripta elegans) with respect to the position of the light sources?

   

   View hundreds of other Biology EE exemplars on Clastify

   Click to view exemplars

   

   Grade received: B

   To what extent does high intensity interval training (HIIT) effect the maximum oxygen uptake (VO2max) in sedentary populations?

   

   Grade received: A

   How do different concentrations of two cytokinin hormones: Kinetin (0.5, 1 and 1.5 mg/L) and 6-Benzylaminopurine (1.5, 2 and 2.5 mg / L) affect the growth of Lactuca sativa, measured by height, number of leaves and dry mass, separately and combined over 5 weeks?

   

   Grade received: A

   To what extent is blood pressure related to the development of Alzheimer’s Disease in people in age above 50?

   

   Grade received: A

   To what extent do phytochemicals such as resveratrol, glyceollin and epigallocatechin-3-gallate (EGCG) possess comparable antibacterial effects against Staphylococcus aureus bacteria to a non-prescription otitis externa (OE) treatments such as Ciprofloxacin using Bacillus subtilis as a prokaryotic model organism?

   

   View hundreds of other Biology EE exemplars on Clastify

   Click to view exemplars

   

   Grade received: D

   What is the effect of seawater mixture (0%, 5%, 10%) on the germination of black chickpeas (Cicer arietinum), Green Gram (Vigna radiata) and Fenugreek (Trigonella foenum-graecum) for 5 days and their subsequent growth when watered using tap water for 10 days where growth was measured by plant height (±0.05 cm) and dry mass (±0.001 g)?

   

   Grade received: A

   To what extent does the presence of acetaminophen (Tylenol), Polymixin B (Polysporin), and diphenhydramine hydrochloride (Benadryl) in the growth medium of Cotoneaster acutifolius affect the average change in leaf length over a period of 15 days in five different concentrations?

   

   Grade received: A

   To what extent do cosmetic procedures like bleaching and heat straightening affect the tensile strength of Homo sapiens hair?

   

   Grade received: A

   To what extent do different honey brands affect their antibacterial activity to test their hydrogen peroxide content using permanganometric titration?

   

   Grade received: A

   “Is the cone repair a suitable approach for severe forms of Ebstein anomaly?”

   

   Grade received: A

   What is the effect of different light combinations on the movement of semiaquatic turtles, red-eared slider (Trachemys scripta elegans) with respect to the position of the light sources?

    

8. Salinity Stress on Magnetoprimed Plants: Salinity stress, caused by high salt levels in soil or water, adversely affects plant growth and productivity by disrupting physiological and morphological traits. Through this topic, you would assess the Effect of Salinity Stress (0, 50, 100, 150, 200 mM NaCl) Measured Through Microscopic (Stomatal Aperture) and Morphological (Leaf Area, Leaf Dry Mass, and Root Length) Characteristics on Pre-Treated Radish seeds. 
   
    

9. Oil spillages: Prompted by a 2020 oil contamination incident near the Danube River, the investigation examines the effects of oil spills on plants, focusing on Ceratophyllum demersum. The experiment aims to simulate the circumstances of the spill to observe the impact of varying oil spill durations on plant mass. Different types of oils, such as light and heavy oils, have varying toxic effects on plants, with heavy oils containing heavy metals that can penetrate plants and affect their cellular and molecular functions.
   
    

10. Ultra-processed food diet: The transition to highly processed foods in modern diets has contributed to the global rise in obesity, affecting people worldwide. Young adults aged 15 to 25 are particularly prone to excessive consumption of ultra-processed foods, regardless of their geographical location, due to factors like flavor, accessibility, and affordability. The research aims to explore the relationship between frequent consumption of ultra-processed foods and the prevalence of overweight and obesity among high school and college students in Poland and Thailand, amid the global shift towards heavily processed diets.
    
     

11. Pollution of oestrogens into freshwater systems: In this case, you could analyse how a synthetic oestrogen (17α-ethinylestradiol) affects the gene expression of fathead minnows (Pimephales promelas) and what effects this leads to. Pollution disrupts ecosystems, with aquatic environments particularly vulnerable due to inadequate waste disposal. Elevated oestrogen levels in water pose reproductive risks to fish, potentially altering breeding behavior and impacting the entire ecosystem. This investigation focuses on the effects of synthetic oestrogen on fathead minnow gene expression, aiming to raise awareness about this emerging issue and its consequences for biodiversity. 
     
     

12. Lactase-containing dietary supplements: Lactose intolerance affects 65% of adults globally. Lactase enzyme supplements allow individuals to enjoy dairy without repercussions by aiding lactose digestion, highlighting the importance of enzymes like lactase in breaking down lactose into digestible sugars. Here you would assess to what extent the different types and brands of dietary supplements differ if the prescribed dosage used  is measured as the amount of glucose produced after being treated with different supplements in a given time period. 
     
     

13. Antimicrobial effects of metals: This EE was aimed to investigate methods of inhibiting bacterial growth, especially the oligodynamic effect which refers to the ability of metals to have toxic effects on bacterial cells. In this topic, the antimicrobial properties of metals: copper, barium and silver were tested in inhibiting the growth of bacteria such as Staphylococcus albus and Micrococcus luteus. 
    
     

14. Single-celled organism: The research aims to investigate whether Physarum polycephalum, a single-celled organism, can adapt and learn to navigate around an obstacle, represented by table salt, to reach a designated goal. Despite lacking a brain, it exhibits signs of intelligence by adapting to its environment and making decisions in search of food. The experiment involves observing the organism's movement towards food placed in a container, with salt serving as a barrier, to determine its ability to overcome obstacles through habituation. 
    
     

15. Digestion rate of oatmeal: The experiment examines the impact of pre-soaking oatmeal (Avena sativa) for varying durations (2, 6, and 8 hours) on the enzymatic breakdown by bacterial amylase and its correlation with the Glycemic Index. By soaking the oats, the starches within may break down more effectively, affecting the rate of energy production in the body. After conducting the experiment with equal parts oatmeal and water soaked for different durations, the absorbance of the resulting liquid mixed with alpha amylase was measured using a colorimeter. 
     

Hopefully you discovered an interesting topic for your Biology extended essay. If you would like to see more examples, head to the Clastify website! We are here to help you with the entire writing process, don't hesitate to submit your EE for a professional Review.