The human microbiome includes trillions of microorganisms such as fungi, yeast, bacteria and viruses, most of which are located in our gastrointestinal tract. When these healthy biomes are disrupted and become imbalanced, a “pathobiome” may form which can cause numerous health problems. Traditionally, scientists believed that the brain was a sterile environment, protected by the blood-brain barrier. However, recent research has suggested that the brain may possess its own unique microbiome that could impact the health of the brain and is redefining our understandings in neuroscience.
In advanced imaging and molecular studies of brain samples from those with Alzheimer’s and those without, researchers found evidence of microflora in all samples. However, there was up to seven times more bacteria and different profile proportions in the Alzheimer’s samples. Many of these microbes are thought to have functional roles, perhaps as immune system regulators or in sustaining our metabolic health. But how can microorganisms enter across the blood-brain barrier, a filter designed to keep out pathogens and toxins? One theory is that the blood-brain barrier becomes compromised and damaged due to ageing or inflammation.
Once microbes have entered the brain, it is thought that in an imbalance in microfauna can lead to the inflammation. If this inflammation becomes too extreme, it can lead to the damage of brain cells that lead to neurodegeneration. A known characteristic of Alzheimer’s is the buildup of toxic proteins that include beta amyloid and tangles of tau. These proteins activate the brain’s immune cells which are known to cause inflammation as a response mechanism. If microorganisms are causing inflammation through this triggering of immune responses, it can signal a link between their presence and an increases in the risk of Alzheimer’s disease. It is also believed that microbes in the gut can have an impact on the health of the brain – known as the gut-brain axis. New research is investigating how gut bacteria influence the brain through the nervous and immune systems.
If it is proven that microbes really do influence neurodegenerative diseases, new treatments could help to stem their impact, such as probiotics or specialised diets. Although in its early stages, a promising study showed that treating mice with antibiotics weakens the signs of Alzheimer’s by decreasing the amount of amyloid-ß (Aß) peptides in the brain. This suggesting that microbes were indeed playing a part in their neurodegenerative decline.
If you have an interest in studying Biology or Human Biology, Oxford Open Learning offer the chance to do so at several levels. You can also Contact Us.
Human Biology Fast Track IGCSE
Every year, salmon undertake what might seem like one of the most illogical journeys in nature. They leave the sea and swim up estuaries, returning to the rivers where they were born, a journey that can span hundreds of miles. It typically takes salmon about 14 to 21 days to swim upstream to their spawning grounds, guided by the memorised scent of their birthplace and the Earth’s magnetic field . They’re engaging in an epic pilgrimage back to their natal rivers—the exact location where they were born — to spawn, reproduce, and start the whole lifecycle again.
This behaviour is a true call of nature, and an extraordinary one at that, as most salmon die of exhaustion once spawning is completed. This journey is partly explained by the Salmon’s anadromous nature, meaning they are born in freshwater, migrate to and live in the saltwater sea during adulthood, and return to freshwater to spawn. As a point of note, Sturgeon are also known to exhibit this extreme migratory behaviour. This anadromous behaviour of Salmon is controlled by their intrinsic biological clock that triggers spawning behaviour which is vital for the continuation of their species. But this still begs the question: Why not spawn near the river mouth if they only seek freshwater? Why make the exhausting and nearly impossible journey back to their birthplace just to reproduce? It seems to be an extreme course of action without obvious justification!
Experts explain that estuaries and river mouths are not ideal for spawning because they are often murky, silt-laden environments with low oxygen levels. These areas are also partially saltwater and are wide, exposed spaces that serve as prime hunting grounds for predators. In contrast, the freshwater areas further upstream are much more suitable for spawning, and progeny survival rates are much higher.
These upstream environments are rich in dissolved oxygen, which is essential for both the adult salmon and their eggs for different reasons. The well-oxygenated water helps salmon endure the grueling journey, which can be compared to running multiple marathons in succession.
After the eggs are laid far upstream, they benefit from the highly oxygenated water, which boosts their survival and maturation rates. Additionally, there are fewer predators in these areas, especially since salmon typically lay their eggs in gravel beds in shallow stretches of rivers, which larger predators cannot easily access.
If you are interested in studying Biology, Oxford Open Learning offer the chance to do so at several levels, listed below. You can also Contact Us.
With access to better food and health care, people are increasingly living longer; the global average life expectancy in 2024 is 73 – over double the number from 1900. Technology is playing a large part in future life expectancy and later quality of life, with healthcare innovations such as personalised medicine and digital robots shaping the future and challenging the perceptions of what it is to become old.
Wearable technology has become extremely fashionable as people become conscious of adopting healthier lifestyles. Older generations are becoming more digitally savvy and are taking advantage of such devices to measure their vital signs such as heart rate and blood pressure. Many devices are now available with a personal emergency response systems (PERS) which enable the user to send an alert to a primary caregiver or emergency services; some can also detect falls and accidents.
These devices act as a useful remote monitoring system and were hugely popular during the COVID-19 pandemic. They enable less hospital trips and caregiver visits as health vitals can be remotely tracked. Online services have also allowed older generations to become more independent with the convenience of digital health record access and medical appointment scheduling.
AI and personalised medicine are making impactful changes to the quality of life in older individuals by offering personalised diets, exercise routines and medications. Using advanced software, genetic information and lifestyle factors can be considered to make specific recommendations for more effective treatments that have fewer side effects. Big data can use statistics from the general population to help to identify patterns and trends that predict illnesses before they arise.
As older individuals become less physically able, home technology such as voice assistants and smart home hubs will play a part in everyday life such as operating lights and curtains or ordering shopping and medications. Mobility aids such as smart walkers and wheelchairs are becoming equipped with enhanced stability, stairclimbing capabilities and posture management features, enabling added comfort and accessibility.
Robotic aids for the elderly are also becoming popular to help maintain a sense of independence and improved quality of life. Loneliness is an increasing factor amongst the older generation. Human robotic companions can provide social interaction and emotional support that help increase mental health and wellbeing while service assistant robots can help ease physical tasks such as loading the dishwasher and preparing food and drinks.
If you are interested in studying Biology or Human Biology, Oxford Open Learning offer the chance to do so at several levels, listed below. You can also Contact Us.
Human Biology IGCSE Fast Track
Agging is an ongoing process with gradual physiological changes that lead to senescence – a decline in biological function and increased vulnerability to metabolic stresses. Theories of ageing have been debated since the ancient Greeks. There is currently no one theory that covers all the different aspects of ageing; many theories fall into the programmed (biological clock) and damage or error related categories. Some of the popular theories around ageing include genome damage to DNA, telemere shortening, misfolding of proteins, cell senescence and stem cell exhaustion.
During genomic instability, our DNA can become damaged due to external factors (such as UV light exposure) and internal factors (such as mutations). Damaged DNA can affect gene expression and transcription which can lead to dysfunctional cells.
Telemeres are the caps contained on the ends of DNA strands that protect them from damage. With each cell division, the length of the telomeres shorten; cell apoptosis (death) can eventually occur if the telomeres become too short.
Proteostasis is the process involving the folding, chaperoning and maintenance of protein function which keeps cells healthy. As protein damage occurs (e.g. through oxidation) over time, chaperones can become distracted with irreversibly damaged proteins, leading to an accumulation of newly misfolded proteins.
Cell senescence occurs when old and damaged cells cease to replicate. Senescent cells release senescence-associated secretory phenotype (SASP) molecules which, in accumulation, can alter and disrupt the surrounding environment and cause inflammation and cancer.
Stem cell exhaustion can occur when our stem cells lose their ability to divide or are unable to be replaced. Stem cells are vital to tissue regeneration and their loss contributes to the ageing process.
As technologies, medicine and our understanding of the ageing process improve, so has the average human lifespan. People are living longer and this trend is predicted to continue into the future.
There is currently a wide range of scientific research being undertaken to reverse the ageing process, with a focus on its different aspects. T cells, a type of white blood cell which defend our bodies against bacteria and viruses, are being researched and reprogrammed to target cancer cells. Senolytics are specific drugs that has been synthesised to target and remove senescent cells and their damaging SASP molecules. Telomerase activation works on the theory that using drugs to induce an enzyme called telomerase to extend chromosome telomeres will effectively increase an organism’s lifespan.
The ageing process is a topic of high scientific interest, although it is complicated and involves many factors which are not yet fully understood. It is thought, for example, that telomeres act as a biological safety device to stop cancerous cells from proliferating. While we are not yet able to reverse ageing, significant progress has been made to allow the slowdown or the partial reversing of it.
If you are interested in studying Human Biology or Biology, Oxford Open Learning offers you the chance to do so at a number of levels, listed below. You can also Contact Us.
Human Biology Fast IGCSE Track
The modern-day natural environment we live in is very different to the one our grandparents knew. It is changing at an increasingly rapid pace. And from the air we breathe to the places where we live, it can also affect our physical and mental health over time. As the human population grows, so urbanisation expands and global warming rises, understanding the complex relationship between our health and our environment is important to the future of our well-being.
With the increase in human industrialisation over the last 200 years, the quality of our air and water supply has drastically declined. Chemicals such as carbon monoxide and nitrogen dioxide concentrations have increased, with fine particulate matter causing the most serious health issues and premature mortality. Air pollution alone is responsible for 2 million deaths in China per year.
In developed countries, water contamination from urban runoff, industrial waste, pesticides and eutrophication can lead to health issues such as kidney disease and cancer. In developing countries, limited infrastructure and poor sanitation often leads to contaminated water supplies, containing harmful bacteria and diseases which when consumed and contracted cause illnesses such as cholera, diarrhoea and dysentery.
Climate change to our environment exacerbates the effects of air pollution through changes in weather patterns and increased heat levels. It can also encourage the spread of insects that carry infectious diseases, such as ticks and mosquitoes, create storm surges from increased precipitation, leading to industrial overflow and increase draughts, leading to agricultural failure and malnutrition in poorer countries.
The loss of green spaces in urban areas can lead to heat islands and the reduction of opportunities for recreational activity. Poor housing conditions or overcrowding can increase the spread of diseases; COVID-19 for example, is more prevalent in urban areas, where 90% of all reported cases have taken place. Urban spaces also see a higher, disproportionate number of injuries or fatalities compared to rural areas, while increases in noise pollution such as that from construction and traffic can lead to poor sleep, hypertension and heart disease.
The urbanisation of environment also provides opportunities for education, healthcare and employment opportunities, leading to better prospects and well-being. It has also, however, been associated with increased levels of mental health decline, due to social isolation and lack of green spaces. Having a close-knit community and a strong social network is important to our well-being and can help improve our mental health and enhance our recovery from illnesses.
Addressing environmental issues such as pollution, climate change and inadequate infrastructure will help to develop a healthier population. Countries such as Singapore and Denmark are already leading the way forward in urban environments with integrated urban greenery, sustainable development, bicycle infrastructures and community engagements spaces. Whether the rest of the World can follow them as well in time remains to be seen.
If you are interested in studying a Science subject, Oxford Open Learning offer the chance to do so at a number of levels, listed below. You can also Contact Us.
Human Biology IGCSE Fast Track
Mankind has sought to harness the healing power of plants for millennia, if not since the dawn of our existence. The oldest evidence for medicinal plant usage was from over 5,000 years ago, written in Sumerian clay from Nagpur, India. Through the ages, we have learned that certain plants can provide us with the vital ingredients for medicines and treatments, and how they do so. Many plants grown today were originally chosen for their medicinal properties as part of a physic or herbal garden.
During the 1700s, medicinal plants were collected or ‘simpled’ from the wild to create tonics, oils and ointments and were documented in botanical encyclopaedias called herbals. These books were often unstructured when they were first produced, but with the development of printing technology, depictions became more accurate and reliable. There was very little scientific basis for herbal usage during this time, and reliance was heavily made on observations, traditional beliefs, religion and folklore – linking the physical appearance of a plant to a human body part for example, was not an uncommon method of reasoning for treatment.
Many medicinal plants are effective due to their bioactive compounds such as alkaloids, flavonoids, phenols and saponins. These substances are often used by the plant for their own survival but when consumed, have pharmacological effects such as acting as an anti-inflammatory, antioxidant or antimicrobial. Once the mechanisms behind these bioactive compounds have been understood, they can be extracted for the production of medicinal drugs. For example, morphine is created from opium extracted from poppy seeds, while aspirin is synthesised from salicylic acid extracted from willow bark. Some ingredients such as Digoxin can only be sourced from plants such as foxgloves and cannot be artificially synthesised.
One area that medicinal plants are helping us is in the battle against malaria. Many medicines used contain the plant-based compounds Quinine (extracted from the fever tree) and artemisinin (extracted from wormwood). Unfortunately, anti-malarial drug resistance to these compounds is becoming a growing problem in tropical regions.
A survey published by Kew Gardens sought to identify the traditional plants used by indigenous people of Latin America to combat malaria and identified over 1,000 plants, with many not scientifically tested against the malaria parasite. They discovered that many of these plants were grouped closely together in the Tree of Life (a plant family tree) and speculated on other, similar plants which had not yet been identified. Locals may not have had access to these plants because they were only found in other countries.
The medicinal properties of plants have been important to our ancestors throughout history and will continue to contribute towards the future of modern medicine. However, with so much biodiversity lost each year, thousands of plants and their potential drug use vanish from existence on a regular basis. As we continue to discover new natural bioactive compounds and their medicinal applications, we must continue to protect our natural environments to safeguard future medical breakthroughs.
If you are interested in studying a Science subject, Oxford Open Learning offer several at a variety of levels, listed below. You can also Contact Us.
Human Biology Fast Track IGCSE
Deoxyribonucleic acid (DNA) is one of the most important molecules in all living things; it contains a unique sequence of information needed for life. There are in fact over 3 billion sequences in the human genome which are responsible for our genetic makeup. Each DNA strand would measure 2 metres in length once unravelled and serves an important purpose in protein synthesis, heredity and evolution.
DNA was discovered in 1953 by Francis Crick and Jim Watson. Their research was significantly aided by Dr Rosalind Franklin’s research and famous Photo 51 of DNA’s signature double helix, allowing Crick and Watson to complete their molecular model.
We can think of DNA as a large book containing all of our genetic information. This is known as our genome. It is made up of a very long double helix of paired nucleotides. Each nucleotide contains one of four bases – adenine with thymine and cytosine with guanine. They form the rungs of the DNA ladder with each base pair making up the ‘letters’ of our book. The order of these letters form sequences known as genes which can be thought of as ‘paragraphs’. It’s these sequences that make each person and organism unique. In each cell, our entire DNA sequence is broken up and stored into 23 separate pairs of chromosomes, forming the ‘chapters’ of our book.
DNA serves as a store for all of our genetic information. It has the ability to replicate itself in order to ensure that when our cells divide, the new cells contain a perfect DNA copy. It carries out protein synthesis through the process of transcription. When a gene is ‘switched on’, a molecule called RNA polymerase attaches to the start of the gene sequence and unzips the DNA double helix into two single strands. A messenger RNA (mRNA) copy of a gene sequence is synthesised as free bases attach to one of the single stands in a complementary fashion. Once the gene sequence has been fully read, the mRNA is processed – sections of mRNA are removed or added.
Within humans, the mRNA leaves the nucleus of a cell into the cytoplasm where protein production molecules called ribosomes produce an amino acid chain based on the mRNA sequence. The completed amino acid chain is then released to form a protein molecule. The sequence of amino acids within the protein determines its structure and function, which ultimately determine an organism’s characteristics and traits.
By determining our features and characteristics, DNA plays an important part in evolution and heredity. Organisms inherit unique traits from their parents through the process of reproduction; here each offspring contains one half of each of their parents DNA to create a new genetic makeup. This process creates genetic diversity in a species which can aid its adaption and survival.
It is interesting to note that all humans are 99.9% identical to each other – it’s this 0.1% difference in our makeup that makes us so unique. Scientists are able to compare DNA sequences within humans to understand our genetic ancestry, migration patterns and evolution.
Modern day medicine and genetic discoveries have heightened our understanding of the human genome. DNA errors or mutations which can lead to diseases and genetic disorders can now be addressed through techniques such as gene therapy. As our understanding of DNA increases, so will our ability to improve our health through personalised medicine, precision agriculture and environmental conservation.
If you are interested in studying a Science, Oxford Open Learning offer you the chance to do so at a number of levels, shown below. You can also Contact Us.
Human Biology IGCSE Fast Track
Our body is highly complex, with many physiological processes taking place within its tissues and organs. Every day, it is subjected to changes in its internal and external environment. Homeostasis is the process by which our bodies maintain balance and stability against these stresses. The word is derived from the Greek word “homeo” meaning similar to, and “stasis” meaning to stand still. The process of homeostasis protects the body, helping it to survive what could otherwise be life-threatening situations, by maintaining a balance in such things as temperature, glucose, water and pH levels.
Perhaps the most widely known example of homeostasis is the regulation of blood sugar levels by the pancreas. If not regulated properly, conditions such as diabetes can occur from hyperglycemia (high sugar levels) or hyporglycemia (low blood sugar levels). The pancreas releases two key hormones to control sugar levels; insulin helps to control the rate of glucose uptake by cells while glucagon controls the release of glucose from the body’s glycogen stores. These hormones work closely together to regulate sugar levels during meals or periods of exercise.
In order to properly function, the body needs to be kept at around 37 degrees Celsius – each of our bodies has a very slight variation in this temperature. A deviation from this temperature, even by a few degrees, is potentially very dangerous.
A region of our brain known as the hypothalamus helps to monitor our body’s temperature and actions responses such as sweating, shivering or restricting blood flow to the extremities to help maintain its core temperature. Sometimes, our bodies override our natural temperature in the event of a viral or bacterial infection, creating a fever to help stimulate our immune system and impede a foreign attack.
Maintaining our fluid levels and electrolytic balance is essential for our health and our body controls this through the regulation of water intake and excretion via our kidneys. The average adult needs around 2.5 litres of water a day to achieve this balance. When low levels of water are detected, the hypothalamus synthesises a hormone known as antidiuretic hormone (ADH) which communicates to the kidneys to reabsorb more water.
The pH levels for different parts of the human body vary widely, from pH 1 gastric acid to pH 8.1 pancreatic fluid. Human blood needs to have a pH level of between 7.35-7.45 (slightly alkaline) to be within a healthy range. Having the appropriate blood pH level allows proper cellular and enzyme functionality and is regulated by the bicarbonate ion – carbonic acid system, the lungs and kidneys. The lungs are able to regulate blood pH rapidly through the rate of exhalation of carbon dioxide. The kidneys on the other hand have a slower impact on pH levels by excreting acids or synthesising bicarbonate.
We can see that the human body processes are complex, and there is a vital need for regulation to ensure proper functioning and health. This is achieved by the body’s coordination of all its systems working in harmony, in which the hypothalamus plays a key role. Homeostasis allows us to regulate ourselves in the often harsh conditions of the natural world, allowing us to cope with extreme temperature variations or periods of famine. It has also been attributed as a driving force for evolution in organisms.
To mark British Science Week, from the 8th to the 17th of March, let’s shine a light on some of the greatest contemporary British minds in Science, Technology, Engineering and Maths (or STEM, for short).
Sue Black is a Professor of Computer Science at Durham University. An outspoken and active social media campaigner, Sue led a campaign to save Bletchley Park and is one of the most influential women in tech. An advocate for equality, diversity, and inclusion, particularly for women in computing, she founded BSCWomen, an online network for women in tech, and #techmums, a social enterprise which empowers mothers and their families through technology. In the 2016 New Year Honours, Sue received an OBE for services to technology.
Timothy Berners-Lee is a computer scientist and software engineer who is most famous for inventing Hypertext Transfer Protocol, or HTTP, and the World Wide Web. He also created the first internet browser, the HTML language, and the URL system, and in 1991 was named one of the 100 Most Important People of the 20th Century by Time Magazine. In 2004, Timothy was knighted by Queen Elizabeth II for his pioneering work, and he now works as Professor of Computer Science at the University of Oxford. He is also a professor emeritus at the renowned Massachusetts Institute of Technology (Often referred to as MIT).
Maggie Aderin-Pocock is a space scientist, educator, and communicator. Throughout her career, she has worked on some of the most prestigious projects at some of the UK’s top universities and is currently an honorary research associate within the Department of Physics and Astronomy at University College London and Chancellor at the University of Leicester. She is also a presenter of the TV show The Sky at Night and does much outreach work to engage young people in science. Her academic work now focuses on building instruments and equipment to aid the fight against climate change. Maggie received an MBE for services to science education in 2009 – an honour that was upgraded to OBE in this year’s New Year Honours.
Donald Palmer is an Associate Professor of Immunology at the Royal Veterinary College where his current research interests focus on the ageing of the immune system. After completing his PhD at King’s College London, he took post-doctoral fellowship positions at Cancer Research UK and Imperial College where he carried out research on lymphocyte development. Donald is also a co-founder of the Reach Society – an initiative to inspire, encourage and motivate young people, particularly young Black men and boys, to achieve their full potential.
Roma Agrawal is a structural engineer who is most known for her work on The Shard in London. Born in Mumbai, she completed her undergraduate degree in physics at the University of Oxford and gained an MSc in structural engineering from Imperial College London. She has gained several awards for her work, including the Institute of Structural Engineers’ Structural Engineer of the Year’ award in 2011 and, more recently, the Royal Academy of Engineering’s ‘Rooke Award for Public Promotion of Engineering’. She is an active public speaker and advocate for diversity and inclusion within STEM.
Saiful Islam is Professor of Materials Modelling at the University of Oxford. He gained a chemistry degree and PhD from University College London and his research interests focus on gaining a deeper understanding of the processes that exist within energy materials, particularly batteries. As well as numerous academic awards and honours, Saiful holds a Guinness World Record for the highest voltage lemon battery (usually a low powered, simple battery used for the purposes of education).
To learn about more successful British scientists, visit the Inspiring Scientists website.
If you are interested in studying a Science or Maths, Oxford Open Learning offers the opportunity to do so at a variety of levels, listed below. You can also find advice via our Contact Us page here.
Fast Track Human Biology IGCSE
Since the discovery of penicillin by Alexander Fleming in 1928, antibiotics have revolutionised the field of medicine, saving countless lives and providing effective treatments for bacterial infections. However, the rise of antibiotic resistance has become a pressing global concern, posing a significant challenge in the battle against microbes.
Penicillin, the first antibiotic, was a breakthrough in the fight against bacterial infections. It was effective against a wide range of pathogens and played a pivotal role in reducing mortality rates from infectious diseases. The discovery of penicillin paved the way for the development of numerous other antibiotics, each targeting different types of bacteria and providing a diverse arsenal against infections.
For several decades, antibiotics were hailed as medical miracles, and their availability led to a sense of complacency. However, the misuse and overuse of antibiotics have contributed to the emergence of antibiotic-resistant bacteria. When antibiotics are used improperly or unnecessarily, bacteria can develop mechanisms to survive and grow despite the presence of these drugs. This has led to the rise of superbugs, such as methicillin-resistant Staphylococcus aureus (MRSA) and carbapenem-resistant Enterobacteriaceae (CRE), which are difficult to treat and pose a significant threat to public health.
The battle against antibiotic resistance involves a multi-pronged approach. Firstly, there is a need for responsible use of antibiotics. Healthcare professionals must prescribe antibiotics judiciously, ensuring that they are used only when necessary and that the appropriate dosage and duration are followed. Patients, too, play a crucial role by adhering to prescribed antibiotic regimens and not pressuring their doctors for unnecessary prescriptions.
In addition to responsible use, efforts are underway to develop new antibiotics and alternative treatments. However, the pipeline for new antibiotics has been dry in recent years, largely due to economic factors and the challenges associated with developing effective drugs. This highlights the need for increased investment in research and development of new antimicrobial agents.
Another important aspect of the battle against microbes is infection prevention and control. By implementing stringent hygiene practices in healthcare settings, such as hand hygiene, proper sterilisation, and effective waste management, the spread of antibiotic-resistant bacteria can be minimised. Public awareness campaigns play a crucial role in educating individuals about the importance of hygiene and responsible antibiotic use.
Furthermore, surveillance and monitoring of antibiotic resistance patterns are essential for understanding the scope and impact of the problem. This information enables healthcare providers and policymakers to make informed decisions regarding treatment protocols and infection control strategies. Collaboration between healthcare professionals, researchers, policymakers, and the public is vital in combating antibiotic resistance.
The battle against microbes and antibiotic resistance is an ongoing and complex challenge. It requires a multifaceted approach that addresses responsible antibiotic use, research and development of new treatments, infection prevention and control, and surveillance. By taking collective action, we can preserve the effectiveness of antibiotics and ensure that future generations have access to effective treatments for bacterial infections. The fight against microbes is a reminder of the ever-evolving nature of infectious diseases, as if recent times have not taught us, and of the need for continuous innovation and vigilance in the field of medicine.