REVISE GCSE Biology - A podcast by Seneca Learning

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 agains...

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, us...

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 resi...

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 noti...

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 hel...

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...

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 contribut...

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...

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 accumul...

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, ...

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 ...

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 agricultura...

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 diseas...

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, ...

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...

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 ...

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 ...

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...

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...