Revise Gcse Biology

In this episode, we will discuss the alveoli in the circulatory system.Alveoli are microscopic air sacs within the lungs where the crucial exchange of oxygen and carbon dioxide occurs between air and blood through diffusion. Their structure is highly adapted for this vital process, featuring a vast surface area and an extensive network of surrounding capillaries that ensure a rich blood supply and minimal diffusion distance. Deoxygenated blood flows to the alveoli, where it releases carbon dioxide and absorbs oxygen before returning to the body as oxygenated blood. Notably, in some marine mammals like whales, alveoli function differently during deep dives, temporarily shutting down as these animals rely on stored oxygen.Don't miss out on subscribing for more educational content tailored to help you succeed in your exams. Perfect for AQA, OCR, Edexcel, CIE and WJEC exam boards.⁠Click here to see all of our GCSE Biology content!

In this episode, we look at transportation in cells. We will explain how substances move into and out of cells, highlighting three key mechanisms. Diffusion is described as the movement of particles from high to low concentration areas. Osmosis is presented as a specific type of diffusion focusing on the movement of water across a semipermeable membrane. Finally, active transport is characterized by the movement of particles against their concentration gradient, requiring energy. The episode further clarifies the difference between diffusion and osmosis using the example of diluting blackcurrant squash in water.Don't miss out on subscribing for more educational content tailored to help you succeed in your exams. Perfect for AQA, OCR, Edexcel, CIE and WJEC exam boards.⁠Click here to see all of our GCSE Biology content!

In this episode, we will discuss plant hormone uses and light investigation.Plant hormones are valuable tools in agriculture and horticulture, manipulating plant growth for various purposes. Auxins find use as herbicides and rooting agents, whilst ethene regulates fruit ripening. Gibberellins stimulate flowering, fruit enlargement and germination. We also outline an investigation into the impact of light on seedling development, using mustard or cress seeds. By varying light exposure, students can observe its effect on plant height and phototropism. This experiment highlights the influence of environmental factors on plant growth.Don't miss out on subscribing for more educational content tailored to help you succeed in your exams. Perfect for AQA, OCR, Edexcel, CIE and WJEC exam boards.⁠Click here to see all of our GCSE Biology content!

In this episode, we look at evidence supporting the theory of evolution. Fossil records demonstrate the incremental changes in organisms throughout extended timeframes. Furthermore, the development of antibiotic-resistant bacteria is highlighted as an example of natural selection. The rapid reproduction of bacteria, coupled with mutations, leads to resistant strains when exposed to antibiotics. Surviving bacteria pass on their resistance, creating new lineages.Don't miss out on subscribing for more educational content tailored to help you succeed in your exams. Perfect for AQA, OCR, Edexcel, CIE and WJEC exam boards.⁠Click here to see all of our GCSE Biology content!

This episode explains the role of carbon dioxide in the environment. It highlights that carbon dioxide is a greenhouse gas and discusses both its natural removal and release. Photosynthesis by plants and algae naturally removes carbon dioxide from the atmosphere while respiration is a natural source of release. Human activities, such as burning fossil fuels, also contribute to carbon dioxide emissions. The episode concludes by noting the greenhouse effect is a natural insulation in the atmosphere.Don't miss out on subscribing for more educational content tailored to help you succeed in your exams. Perfect for AQA, OCR, Edexcel, CIE and WJEC exam boards.⁠Click here to see all of our GCSE Biology content!

In this episode, we discuss food farming techniques.Achieving global food security requires more efficient food production methods. The amount of energy transferred between trophic levels in food chains has implications for food production efficiency because only a fraction of energy is passed on. Shortening food chains can, therefore, increase efficiency. Minimising energy loss from livestock through processes such as movement helps as well. Feeding livestock high-protein foods can also increase growth rates and productivity.Don't miss out on subscribing for more educational content tailored to help you succeed in your exams. Perfect for AQA, OCR, Edexcel, CIE and WJEC exam boards.⁠Click here to see all of our GCSE Biology content!

In this episode, we discuss fishing concerns and sustainable fishing. Overfishing is causing significant drops in fish populations worldwide, impacting the livelihoods of fishermen and threatening food security. These declines also disrupt ocean ecosystems and put numerous fish species in danger of extinction. The episode highlights sustainable fishing practices as a solution, including using appropriate net sizes to allow juvenile fish to mature. Fishing quotas that restrict the amount and size of fish caught can help to reduce the negative effects of overfishing.Don't miss out on subscribing for more educational content tailored to help you succeed in your exams. Perfect for AQA, OCR, Edexcel, CIE and WJEC exam boards.⁠Click here to see all of our GCSE Biology content!

In this episode, we explore Biotechnology's role in food production through two key examples. Mycoprotein production, utilising fungal fermentation in vats, creates a high-protein, low-fat meat substitute. Genetic modification is also presented as a means to enhance nutritional value, with golden rice engineered to combat vitamin A deficiency highlighted as a significant application. It is suggested that biotechnology can contribute to addressing both dietary needs and nutritional deficiencies on a global scale. It achieves this through innovative processes such as microbial cultivation and targeted genetic alterations.Don't miss out on subscribing for more educational content tailored to help you succeed in your exams. Perfect for AQA, OCR, Edexcel, CIE and WJEC exam boards.⁠Click here to see all of our GCSE Biology content!

In this episode, we discuss food security.Global food security faces significant challenges in ensuring sufficient, safe, and nutritious food for everyone. High birth rates, particularly in sub-Saharan Africa, exacerbate the issue. The emergence of new agricultural pests and diseases, coupled with the increasing frequency of extreme weather events linked to climate change, threaten crop yields. Conflicts disrupt access to essential food and water resources. Rising costs of agricultural inputs, like fertiliser, further reduce production. Finally, dietary changes in wealthier nations result in substantial "food miles" as food is transported globally, adding to environmental concerns.Don't miss out on subscribing for more educational content tailored to help you succeed in your exams. Perfect for AQA, OCR, Edexcel, CIE and WJEC exam boards.⁠Click here to see all of our GCSE Biology content!

In this episode, we will discuss the reasons for energy wastage. Biomass transfer between trophic levels is not fully efficient due to several factors that limit the energy available for growth. A significant portion of ingested food cannot be digested, and is instead eliminated as waste. Energy is expended during respiration for movement and maintaining body temperature, reducing the energy available for growth and biomass accumulation. Furthermore, metabolic waste products like carbon dioxide, water, and urea are excreted. These processes contribute to an inevitable loss of energy at each level, thus explaining why only a fraction of energy is converted into biomass.Don't miss out on subscribing for more educational content tailored to help you succeed in your exams. Perfect for AQA, OCR, Edexcel, CIE and WJEC exam boards.⁠Click here to see all of our GCSE Biology content!

In this episode, we will discuss decomposers.Decomposers, like bacteria and fungi, are essential recyclers within ecosystems. Their crucial role involves breaking down dead organic material. This decomposition is achieved through the secretion of enzymes. These enzymes digest the waste, resulting in smaller, soluble food molecules. These molecules are then absorbed by the decomposer, facilitating the recycling process. Ultimately, decomposers return vital nutrients back into the environment.Don't miss out on subscribing for more educational content tailored to help you succeed in your exams. Perfect for AQA, OCR, Edexcel, CIE and WJEC exam boards.⁠Click here to see all of our GCSE Biology content!

In this episode, we discuss trophic levels and food chains. Food chains illustrate the transfer of energy through an ecosystem via feeding relationships. Each organism occupies a specific trophic level, beginning with producers like plants and progressing through primary, secondary and tertiary consumers. Predators consume other animals (prey), and apex predators reside at the top of the food chain.  At the base of all food chains are producers and the final stop on the chain is the role that decomposers play. Decomposers recycle organic material by breaking down dead matter, thereby releasing nutrients back into the environment.Don't miss out on subscribing for more educational content tailored to help you succeed in your exams. Perfect for AQA, OCR, Edexcel, CIE and WJEC exam boards.⁠Click here to see all of our GCSE Biology content!

In this episode, we discuss maintaining biodiversity.Efforts are underway to preserve biodiversity through a variety of programmes and initiatives. Breeding programmes aim to bolster endangered species populations, preventing extinction. Protecting and restoring rare and threatened habitats also plays a key role. Furthermore, farmers are being encouraged to maintain field margins and hedgerows to promote biodiversity on agricultural land. Government targets are being implemented to reduce deforestation and emissions. Finally, increased recycling seeks to lessen the impact of landfill sites and resource extraction.Don't miss out on subscribing for more educational content tailored to help you succeed in your exams. Perfect for AQA, OCR, Edexcel, CIE and WJEC exam boards.⁠Click here to see all of our GCSE Biology content!

The episode details the detrimental consequences of global warming on our planet. Melting ice leads to rising sea levels and threatens coastal ecosystems, while shifts in sea ice impact polar animal survival.  An increase in extreme meteorological events like floods and droughts is noted, alongside rising sea surface temperatures that cause coral bleaching and ocean acidification. Altered migration patterns and the spread of diseases like malaria are attributed to the changing climate. Ultimately, the document highlights how rapid climate change threatens biodiversity, especially large animals, due to their slower adaptation rates and discusses the role of the greenhouse effect.Don't miss out on subscribing for more educational content tailored to help you succeed in your exams. Perfect for AQA, OCR, Edexcel, CIE and WJEC exam boards.⁠Click here to see all of our GCSE Biology content!

In this episode, we discuss deforestation.Deforestation, the clearing of forests for purposes like agriculture and biofuel production, has significant environmental repercussions. One key impact is the increase in atmospheric carbon dioxide due to burning trees and reduced photosynthesis. Habitat destruction is another consequence, leading to biodiversity loss and disrupting vital ecosystem services like erosion control. Moreover, land conversion for activities such as rice farming and cattle ranching contributes to methane emissions, further exacerbating greenhouse gas effects. Ultimately, deforestation endangers countless animal habitats.Don't miss out on subscribing for more educational content tailored to help you succeed in your exams. Perfect for AQA, OCR, Edexcel, CIE and WJEC exam boards.⁠Click here to see all of our GCSE Biology content!

In this episode, we look into land use.Human expansion leads to the destruction of peat bogs to make way for farming, fuel and garden compost. Peat bogs are composed of partially decayed plants that store carbon, preventing its release into the atmosphere. However, the destruction of these bogs causes the peat to decay or be burned, releasing significant amounts of carbon dioxide. This destruction not only contributes to greenhouse gas emissions but also results in the loss of biodiversity. Reducing the demand for peat, particularly by using peat-free compost alternatives, is crucial for protecting these vital ecosystems.Don't miss out on subscribing for more educational content tailored to help you succeed in your exams. Perfect for AQA, OCR, Edexcel, CIE and WJEC exam boards.⁠Click here to see all of our GCSE Biology content!

In this episode, we disscuss how human actions are significantly diminishing biodiversity through activities like peat bog destruction and deforestation. Peat bogs, important carbon stores, are destroyed for agriculture, fuel, and horticulture, releasing carbon dioxide and harming habitats. Deforestation, driven by the need for biofuels, cattle farming, and rice cultivation, exacerbates carbon dioxide emissions through burning and reduced photosynthesis. These practices eliminate habitats, lead to a decrease in biodiversity, and result in the release of methane from agricultural activities. Ultimately, the topic demonstrates the direct link between human activities, environmental degradation, and the accelerating greenhouse effect.Don't miss out on subscribing for more educational content tailored to help you succeed in your exams. Perfect for AQA, OCR, Edexcel, CIE and WJEC exam boards.⁠Click here to see all of our GCSE Biology content!

In this episode, we will discuss waste management.Rapid population growth and increased resource consumption have caused significant environmental damage. Industrial processes, agricultural practices, and everyday waste contribute to water pollution via sewage, toxic chemicals, and fertiliser runoff. The land suffers from herbicides, pesticides, nuclear waste, and landfill contents. Furthermore, air quality diminishes due to smoke and gases emitted by power stations and vehicles. The formation of acid rain from sulphur dioxide further threatens forests, freshwater, soil ecosystems and human well-being.Don't miss out on subscribing for more educational content tailored to help you succeed in your exams. Perfect for AQA, OCR, Edexcel, CIE and WJEC exam boards.⁠Click here to see all of our GCSE Biology content!

In this episode, we will discuss biodiversity.Biodiversity, the assortment of species on Earth, is crucial for humanity's future. This episode highlights that since the Industrial Revolution, human activities, particularly those related to production and deforestation, have significantly reduced global biodiversity. Despite early warnings, economic pursuits often overshadowed concerns for the environment. Fortunately, attitudes are shifting, and there are now increasing efforts to protect existing biodiversity and restore what has been lost. These steps are a vital part of repairing some of the harm done.Don't miss out on subscribing for more educational content tailored to help you succeed in your exams. Perfect for AQA, OCR, Edexcel, CIE and WJEC exam boards.⁠Click here to see all of our GCSE Biology content!

This episode will discuss resistant bacteria.Bacterial resistance to antibiotics is a growing concern due to the rapid evolution and spread of resistant strains. Bacteria multiply quickly, and mutations during reproduction can lead to antibiotic resistance. When antibiotics are used, resistant bacteria survive and reproduce, giving rise to new resistant strains that can spread easily. One example of an antibiotic-resistant bacteria is MRSA, highlighting the challenge. The development of new antibiotics struggles to keep pace with the emergence of these strains. Measures to reduce new resistant strains include responsible antibiotic prescribing by doctors, completing prescribed courses by patients, and limiting antibiotic use in agriculture.Don't miss out on subscribing for more educational content tailored to help you succeed in your exams. Perfect for AQA, OCR, Edexcel, CIE and WJEC exam boards.⁠Click here to see all of our GCSE Biology content!