Biology

Cell Activity in Plants

feeds@gcsepod.co.uk (GCSEPod Feeds) — Thu, 01 Jan 1970 01:00:00 +0100

Plants are living organisms that perform the chemical process of photosynthesis. This means that they produce their own food, and do not need to eat like animals. Like all living organisms, plants are made up of cells. They range from the single-celled algae to the multi-cellular, or many-celled, plants such as ferns, flowering plants and trees. Plants must have the ability to perform important reactions like making proteins and respiration to make energy, as well as be able to photosynthesise. Therefore, their cells must have the ability to perform these processes. Plants, like animals, have different organs, which have different functions within the plant. Plant organs include the leaf, stem and root. The cells that make up these organs have specialised structures to enable them to perform their role efficiently. We say that these cells are adapted.

Control of Growth

feeds@gcsepod.co.uk (GCSEPod Feeds) — Thu, 01 Jan 1970 01:00:00 +0100

This title will focus on how plants grow, and how growers can manipulate the growth to their advantage. This is important, as growing crops is a business. The faster crops grow, and the greater the yield, the more profit is made. The first chapter will cover the changes in plants that take place when they grow. As plants are made up of cells, in order for the whole organism to get bigger cells have to multiply and then enlarge. Chemicals called hormones control these changes in the cells, and the way that a group of plant hormones called auxins influence a plant's growth will be discussed. The next two chapters will look at how growers can control the growth of plants. Firstly, how greenhouses can be used to speed up plant growth, and then how hormones can be used commercially.

Nutrition and Energy in Plants

feeds@gcsepod.co.uk (GCSEPod Feeds) — Thu, 01 Jan 1970 01:00:00 +0100

Just like animals, plants need a constant supply of food in order to survive. However, unlike animals, plants don't have to eat their food. Their food is a sugar called glucose, which they make in a process called photosynthesis. Photosynthesis takes place mainly in the leaves. The raw materials that a plant needs are carbon dioxide, water and mineral salts. Without these, the plant would die. Why are each of these things essential, and where do plants get them from? Photosynthesis produces glucose and oxygen. Plants have many uses for glucose. We know that plants grow more quickly in the long, warm, sunny days of summer. Photosynthesis must happen more quickly under these conditions, so what factors can affect the rate of photosynthesis, and are there any limits to how fast plants can grow?

Plant Reproduction

feeds@gcsepod.co.uk (GCSEPod Feeds) — Thu, 01 Jan 1970 01:00:00 +0100

All living things need to reproduce in order to pass on their genetic information and keep their species alive. Plants are no exception. In this title, we will study the various methods that plants use to reproduce and create offspring. Plants can reproduce sexually or asexually. Sexual reproduction involves two individuals and the mixing of genetic material from both parents, in order to produce genetically different offspring. Asexual reproduction involves one parent, and the offspring will all be genetically identical to the parent. Both types of reproduction have advantages and disadvantages. We will look at the reasons why plants use these different methods. Sexual reproduction produces seeds. We will examine the different ways that plants disperse, or spread out, their seeds and the conditions needed in order for the seeds to germinate and start to grow.

Water Relations and Transport

feeds@gcsepod.co.uk (GCSEPod Feeds) — Thu, 01 Jan 1970 01:00:00 +0100

Plants must have a constant supply of water, nutrients such as amino acids and sucrose, and mineral ions in order to grow healthily. Just as we have a circulatory system consisting of the heart, blood vessels and blood to move around the vital materials that we need, plants also have their own way of moving the things they need around. A plant's transport system consists of special tube-like tissues called phloem and xylem. The processes of diffusion, osmosis and active transport are used by plants to load up the xylem with water and mineral ions from the soil, and to pump sucrose and amino acids into the phloem tubes.

Healthy Bodies

feeds@gcsepod.co.uk (GCSEPod Feeds) — Thu, 01 Jan 1970 01:00:00 +0100

In this title, you will learn which foods are healthy and unhealthy, allowing you to make choices about your diet. As you listen, you will learn what a balanced diet is, and why skipping breakfast could lead to you putting on weight. We will also explain how exercise helps keep you healthy and what your Body Mass Index, or BMI, means. The title considers the labels on food packaging, helping you to understand what is in certain foods and allowing you to decide whether something is worth eating. You will also learn about salt, saturated fats, cholesterol and processed foods. In addition, the title will outline the structure of the animal cell, and how it is adapted to perform different functions in the body.

Infectious Diseases

feeds@gcsepod.co.uk (GCSEPod Feeds) — Thu, 01 Jan 1970 01:00:00 +0100

In this title, you will learn about pathogens, microorganisms that are harmful to humans, and how scientists try to combat them. We will consider the different types of pathogens and some of the diseases they cause. You will discover what toxins are, and what your body does if it is infected by a pathogen that produces one. You will also find out more about the vaccines that you might have at school, and why you need injections to go on some holidays. The title will give you an understanding of the hospital superbug MRSA. Finally, you will learn about what happens to our bodies when we take paracetamol or aspirin.

Maintaining the Internal Environment

feeds@gcsepod.co.uk (GCSEPod Feeds) — Thu, 01 Jan 1970 01:00:00 +0100

This title covers the ways in which we try to keep our bodies in a constant state. The scientific word for this constant state is homeostasis. By the end of this title, you will know how your body controls the removal of carbon dioxide, regulates your urine and checks you have enough sugar. It will also consider how the body looks after your temperature and makes sure no microbes infect you. Most of the mechanisms that this title describes occur by negative feedback. This means that if something the body is trying to control increases, it manages it by decreasing it. The process works the other way around as well. If levels are too low, the body will ensure that they increase again. This title also explains how both the nerves and hormones help with these processes.

Medical and Recreational Drugs

feeds@gcsepod.co.uk (GCSEPod Feeds) — Thu, 01 Jan 1970 01:00:00 +0100

In this title, you will learn about the effects of legal and illegal drugs on the body. We will consider alcohol and smoking, as well as other drugs that people use for recreational purposes. The title will outline where drugs come from and how they are developed, from sampling trees and plants in the wild to a product that you can buy from the supermarket. You will also learn that it can take over twelve years to get a drug onto the market, and that even after extensive tests drugs can have damaging effects. After listening to this title, you will have good background knowledge about drugs and how the body changes when they are taken. You will also be able to make links between drugs and the nervous system.

Environments and Ecosystems

feeds@gcsepod.co.uk (GCSEPod Feeds) — Thu, 01 Jan 1970 01:00:00 +0100

Living organisms co-exist harmoniously in ecosystems. This is where natural cycles enable each organism to get the nutrients and energy it needs in order to survive. In this title we'll look first at terminology used to describe an ecosystem, such as 'habitat' and 'community'. We'll then go on to study how energy is passed from one organism to another in food chains and webs, and how pyramids of biomass can be constructed. For farmers to make a profit, it is very important that energy is transferred efficiently. Therefore, they use some of the intensive farming techniques explained in this title. In order for a community to sustain itself, elements such as carbon and nitrogen must be recycled and reused. The final chapters will focus on these cycles.

Please note - Chapter 7 'The Nitrogen Cycle' is not relevant to AQA

Humans and the Environment: Negative Impacts

feeds@gcsepod.co.uk (GCSEPod Feeds) — Thu, 01 Jan 1970 01:00:00 +0100

We humans are just one of the many different organisms that live on our planet. Unfortunately, our success and rapid population growth have had many negative impacts on the environment. This title starts off by looking at how living organisms are able to interact to live successfully alongside one another in their habitats, and it finishes by looking at how humans have upset this delicate balance. We'll discuss the way organisms compete for resources, and why it's important for them to adapt for survival. Then we'll look at the important relationships between organisms, such as that between predators and their prey. This title also explains how scientists study populations of plants and animals, and discusses the problems associated with the rise of human populations, such as pollution and the exhaustion of resources.

Humans and the Environment: Positive Impacts

feeds@gcsepod.co.uk (GCSEPod Feeds) — Thu, 01 Jan 1970 01:00:00 +0100

This title looks at how humans can have a positive impact on the environment. Farmers have a choice. They can farm intensively, or they can opt for the more environmentally friendly approach of organic farming. The first chapter in this title will focus on what organic farming means, on the different methods that organic farmers use, and on how they affect the surrounding environment less than the conventional methods used by intensive farmers. The second chapter will look at what we mean by sustainability. Many choices affect the planet - whether they are made at a local, a national or a global level. We must make sure that these choices do not impact negatively on the environment, so that future generations can continue to enjoy the resources and the huge biodiversity of life that the Earth provides.

Breathing and Respiration

feeds@gcsepod.co.uk (GCSEPod Feeds) — Thu, 01 Jan 1970 01:00:00 +0100

In this title, you'll learn how organisms can convert energy stored in sugar into ATP, which is the energy currency of living things. You'll hear about two alternative ways of liberating energy. One involves the presence of oxygen, and is called aerobic respiration. The other enables energy to be released without oxygen, and is called anaerobic respiration. Some micro-organisms that can respire anaerobically produce alcohol and carbon dioxide. Prolonged intense exercise in animals can result in a build-up of lactic acid in the muscles. This leads to a condition known as oxygen debt. This title also looks at the structure and functions of the respiratory system, including the structure of the lungs. We'll examine the mechanics of getting air into the lungs, so that oxygen in the air can get into our blood, and to the cells that need it.

Circulation

feeds@gcsepod.co.uk (GCSEPod Feeds) — Thu, 01 Jan 1970 01:00:00 +0100

We need a circulatory system to transfer heat around the body to keep our temperature constant; to provide pressure; and to transport substances to and from our tissues. This perfectly formed, intricate system makes sure our blood is sent to the right places, at the right time, in the right direction! In this title you'll learn what our circulatory system is made up of, why we need one, and the features that make it effective at carrying our blood around the body. We'll describe the structure and function of the heart, together with the effects of coronary heart disease, and how to lower your risk of suffering from it. You'll learn about blood: what it's made of, how it helps us fight disease, how it clots, and what happens when this doesn't take place properly.

Digestion and Nutrition in Humans

feeds@gcsepod.co.uk (GCSEPod Feeds) — Thu, 01 Jan 1970 01:00:00 +0100

Humans consume a wide variety of food and drink. This title explains how the digestive system is organised, the roles of the different parts, and how they help the process of digestion. We'll look at how the particles of digested food pass from the intestine into the blood. Chemical reactions involving enzymes break the different foods down into molecules that can be absorbed. We'll find out how the enzymes work, the conditions they need in order to function, and which food groups they act upon. Some enzymes break molecules down, and others build them up. We'll discuss how they do this. Understanding how the digestive system works also means understanding how the breakdown products that aren't needed are dealt with. We'll explain the excretory system, including the urinary system.

Hormonal Co-ordination

feeds@gcsepod.co.uk (GCSEPod Feeds) — Thu, 01 Jan 1970 01:00:00 +0100

One method of sending signals around the body is via the endocrine system. The endocrine system produces hormones, sent into the bloodstream, which travel to target cells. In this title, you'll learn where different hormones are made and how they can have targeted effects. We will discuss adrenaline, a stress response hormone. You'll also learn about insulin, which moderates the amount of sugar in the blood. Diabetes results from the body being unable to produce or detect insulin. The body uses hormones to govern our sexual characteristics, causing the differences between males and females. To understand the female menstrual cycle, we need to learn how the various different hormones work together. We'll look at how the cycle is structured, and how scientists use this information to help couples with low fertility to have a baby.

Reproduction in Humans

feeds@gcsepod.co.uk (GCSEPod Feeds) — Thu, 01 Jan 1970 01:00:00 +0100

Every organism on the planet has resulted from the process of reproduction. Understanding the mechanics of the male and female human body means that we can understand sexual reproduction and pregnancy. What happens once the sperm fertilises the egg? This title examines the stages in development of the zygote through to embryo and foetus until the baby is born. We'll look at the stages of pregnancy, called trimesters, and hear about the changes taking place in the mother-to-be's body. Giving birth to a baby consists of three distinct stages. We'll identify what happens in each stage, and explain what's going on in the mother's body. Sexual intercourse is the means for reproducing the human race. However, there is also the risk of contracting sexually transmitted infections. We'll look at the top four infections, and see how they affect the body.

The Kidneys

feeds@gcsepod.co.uk (GCSEPod Feeds) — Thu, 01 Jan 1970 01:00:00 +0100

It is important for the body to maintain a constant internal environment, called homeostasis. Water homeostasis, or osmoregulation, is the way the body makes sure that the right level of water is in the body. In this title, we will see how the brain and the kidneys keep water levels balanced. The kidney is the organ responsible for filtering our blood and making sure that the right amounts of salts stay in the body, or are excreted. We will look at the structure of the kidney and understand how filtration takes place, before moving on to seeing how the urinary system works. If the kidneys stop working then urea affects the skin, making it turn yellow. There are two solutions to this: undergoing a kidney transplant or kidney dialysis. We will look at the risks and benefits of each.

The Nervous System

feeds@gcsepod.co.uk (GCSEPod Feeds) — Thu, 01 Jan 1970 01:00:00 +0100

The nervous system is a network of specialised cells that work together to coordinate the actions of the body. With the human nervous system we can receive information from the outside environment, and make sense of it. Once we've processed this information, we can build up a complicated internal model of what the world is like. In this title we'll learn about the different parts of the nervous system, and how messages are sent around the body. We'll also look at how signals are sent down neurones and learn about the action potential, and the chemical ions that enable the message to be sent.

The Skin

feeds@gcsepod.co.uk (GCSEPod Feeds) — Thu, 01 Jan 1970 01:00:00 +0100

The skin is our largest organ and is essential for keeping us protected from invasion by harmful bacteria and controlling our body temperature. We judge whether people are scared or are in love by changes in blood flow through their skin. We see people getting old by the wrinkles in their skin. Some people, unfortunately, get skin cancer, often as a result of too much exposure to ultra-violet light from the sun. In this title, we will investigate what skin is, how it grows and how it protects us. Keeping warm is vital for the human body. The skin plays an important role in achieving a constant body temperature through sweating and regulating the blood vessels under the skin's surface. The reason for temperature regulation is to ensure that enzymes work properly. This title will also review that enzyme action.

Evolution and Extinction

feeds@gcsepod.co.uk (GCSEPod Feeds) — Thu, 01 Jan 1970 01:00:00 +0100

In this title, you will listen to theories of how organisms that we know about today may well have evolved over millions of years from single cells. You will also learn about different theories of evolution proposed by scientists from as long ago as the 1700s. Because organisms compete for resources, the ones that are the best adapted survive and this may eventually change the look of a species after many generations. This title explains why dinosaurs are not still roaming around the Earth, and why some people are still interested in their footprints. Finally, you will learn how organisms are preserved over millions of years and how some humans have been preserved in peat bogs.

Genetics and Variation

feeds@gcsepod.co.uk (GCSEPod Feeds) — Thu, 01 Jan 1970 01:00:00 +0100

In this title, you will learn what your genetic material is made from and how a slight change in a small part of this material can have devastating effects. You will learn about the processes that make you look a bit like your parents or even your grandparents, and you will be able to explain why some plants of the same species look different from each other because of the environment they are grown in. This title explains that some disorders people suffer from, like cystic fibrosis, are caused by a single gene on a pair of chromosomes which codes for a faulty protein. You will also be able to explain why X rays used in medical applications have to be treated with caution.

Inheritance

feeds@gcsepod.co.uk (GCSEPod Feeds) — Thu, 01 Jan 1970 01:00:00 +0100

In this title, you will learn about how we inherit our looks and gender from our parents, and how to show the outcomes of a simple genetic cross. We will explain why some people suffer from inherited genetic disorders, even when their parents do not appear to have the disease, and how to work out the chances of passing on such problems. This title covers how and why people may selectively breed animals or plants, and what the advantages and disadvantages of this are. It discusses cloning and the different methods by which it is performed, as well as the human genome project, where scientists have been able to map out our DNA to find the locations of different genes. Finally, you will listen to examples of genetic modification and how it is used today to produce insulin.