This short quiz will assess content covered in this session and prior knowledge.

What does homozygous mean?

Which of the following are heterozygous alleles?

If black fur (B) is dominant to brown fur (b) and two heterozygous rabbits have offspring, what are the chances of the offspring having brown fur? (Draw a punnett square to help you if you want)

If curly hair (S) is dominant to straight hair (s) and a homozygous straight haired dog (ss) and a homozygous curly haired dog (SS)  have offspring, what are the chances of the offspring having straight hair? (Draw a punnett square to help you if you want)

Why do offspring look like both of their biological parents?

Inheritance

﻿Hi, everyone, and welcome to the biological systems and processes topic. I'm Miss Hindle and in this lesson, we're going to be revising, smoking, alcohol, DNA and inheritance. Before we start this lesson, we need to make sure we're ready to learn. And to do that, we need to make sure our phones are off, or at least on silent. Please don't give up at any point during this lesson. There's lots of quickfire questions, and a bit of written work for you to do. So if you're ready, let's get started. All you're going to need for this lesson is a pen and some paper. So if you don't have those pieces of equipment, just quickly pause the lesson and go and get them. Restart the lesson when you're already. In the first part of this lesson, we're going to review smoking and alcohol. I'm going to show you some key facts about smoking and alcohol. I don't want you to write any of these down because there's a lot of information. However, this will be available on the downloadable worksheet. So if you could download it, that would be great. Smoking is addictive because of the chemical nicotine, which is a stimulant. There are over 5000 chemicals released when cigarettes burn, including carbon monoxide. Smoking massively affects health. Smoking damages the alveoli and ciliated cells and also clogs arteries. Smoking when pregnant causes the unborn baby to struggle for oxygen and affects growth and development. Alcohol is addictive and is a depressant. There are many short and long term effects of alcohol consumption. Drinking alcohol whilst pregnant increases the chance of miscarriage, premature birth, baby having a low birth weight, learning difficulties and behavioural problems. I'm going to put a statement on the screen and you're going to decide whether it's true or false. You don't need to write this down just point to the correct one. Smoking causes cancer. Correct. That is definitely true. There is lots of evidence to prove that smoking causes cancer, especially lung cancer. There are some health benefits to smoking. Absolutely not true. There is no health benefits to smoking at all. Smoking tobacco and drinking alcohol is drug taking and is addictive. Well done if you said that that is true. Tobacco and alcohol are both drugs, and they can both become addictive. Remember, not all drugs are illegal. It is legal to smoke tobacco and drink alcohol if you're over the age of 18. Smoking and drinking alcohol when pregnant have negative outcomes. Is that true or is that false? Well done of course is it's true. All of the following chemicals are contained in cigarettes. Which ones cause cancer? All of them. There is many chemicals within cigarettes that cause cancer. These are just a few of them. Now for some quickfire questions again, what is the addictive substance called in cigarettes? Is it carbon monoxide, tar, arsenic or nicotine? Well done, it's nicotine. Nicotine is highly addictive, and is the reason people carry on smoking. What is the substance called in cigarettes that lowers the amount of oxygen the red blood cells can carry? Is it carbon monoxide, tar, arsenic or nicotine? Well done, it is carbon monoxide. When carbon monoxide is breathed in, it binds irreversibly to the haemoglobin within your red blood cells. Once the carbon monoxide binds to haemoglobin, it means oxygen then cannot bind and your cells will have a lack of oxygen. What is the sticky brown substance that is deposited in the lungs and coats the surface of the alveoli? Is that carbon monoxide, tar, arsenic or nicotine? Well done, yes it is. It's tar. I'm going to show you a series of statements. What I would like you to do is decide whether that statement is talking about alcohol or smoking. So here's the first statement. It can make you feel sick and vomit. Is that talking about alcohol or smoking? It's talking about alcohol. Well done. What about this statement then? It is a stimulant. Well done. Smoking contains nicotine, which is a stimulant. It damages the lungs. Is that alcohol or smoking? Well done that is smoking. Smoking severely damages the lungs and causes lung cancer and other respiratory diseases like asthma. It can reduce fertility. Is that true for alcohol or smoking? Well done if you got that because it was a bit of a trick. That is true for alcohol and smoking. Both of these things reduce your chance of being able to have a baby. On the screen there is six questions all about alcohol and smoking. I'd like to pause the lesson now and have a go at answering those on your piece of paper. Restart the lesson when you're ready for me to go through the answers. So let's go through the answers to them questions. Number one, why can smokers seem extremely breathless, carrying out everyday tasks? That's because that alveoli are damaged and there's less gas exchange. Number two, why are smokers more at risk of a heart attack? This is because if the coronary arteries become clogged, less oxygen will be delivered to the heart, and this can cause a heart attack. Number three, what process do substances use to cross the placenta from the mother to the baby? This process is called diffusion. Diffusion is where particles move from an area of high concentration to an area of low concentration. Number four, why is liver damage a common effect of drinking alcohol? The liver filters toxins in alcohol, and each time it does some liver cells die. Remember, the liver can actually regenerate itself. However, if you drink too much alcohol, the cells die at a faster rate than they get regenerated. Number five, why do people smoke? Nicotine is addictive. This is the only reason why people smoke. There is no benefits to smoking at all. Number six, list some short term negative effects of drinking alcohol. There is a few, slow reaction times, blurred vision, slurred speech and loss of balance. There are some other short term negative effects of drinking alcohol too. The next section that we're going to review is all about DNA. I'm going to run through the key facts call about DNA. You don't have to make any notes on this as this page will be available in the downloadable resource. Raw genetic information is made of DNA. DNA is a chemical like anything else in your body. DNA is made up of two backbones and four different bases. The bases are A T, G and C. A always bonds with T, G always bonds with C. The shape of DNA is a double helix. DNA contains genes. Genes are a small section of DNA that codes for a specific protein. DNA makes up chromosomes. Humans have 46 chromosomes. And finally, DNA was discovered by Franklin Wilkins, Watson and Crick. First thing I'd like you to do is match these keywords up to their definitions. You can either write them all out like this and then join them up, or you can write the keyword and the correct definition next to it straightaway. Pause the lesson now to complete this task. So how did you do? Let's have a look. What is a gene? A gene is a small section of DNA that codes for a specific protein. What's a chromosome? They carry all the genetic information in an organism. There is 46 of them in humans. What's a double helix? A double helix is the shape of DNA. And finally, DNA is the chemical that your genetic material is made from. Here's another task for you. What I'd like you to do is copy and complete these sentences. However, when you're copying them down, make sure you fill in the gaps. Use the keywords at the top of the screen to help you. Pause the lesson now and restart when you're ready to go through the answers. Okay, so how did you do? Let's have a look. DNA has a double helix shape. DNA is made a four bases called A, T, G, and C. A gene is a small section of DNA. Each gene provides the information for one protein. Well done if you got all of them correct. If you got any incorrect, just make sure you change them now. So let's have a go some quick questions all about DNA. What is the shape of DNA? Remember, just call out the answers or points the correct one. Well done it is a double helix. Which parts of the DNA codes for specific proteins? Well done that is the genes. What are the bases called that DNA is made up off? Well done it is A, T, G and C. Remember, A bonds with C and G bonds with C. Who did not get recognised for their work on DNA discovery? Well remembered if you said Franklin. Rosalind Franklin had actually already died before Wilkins, Watson and Crick received the Nobel Prize for DNA discovery. The final part of this review lesson is going to be all about inheritance. Here's some key facts about inheritance. Remember, this will be available on the downloadable resource. You don't need to make any notes. We look like our parents because we inherit chromosomes from both parents, half the set from each. For each genetically controlled characteristic, we have two genes, one from each parents, one from sperm and one from egg. Different versions of the same gene are known as alleles. Some alleles are more controlling than others, and are always shown in the individual. These are known as dominant alleles and we represent them using capital letters. The less controlling alleles only show up if both of the alleles are the same. They are known as recessive. We can work out the probability of offspring having a certain characteristic using Punnett squares. On the left hand side of the screen is five key words. On the right hand side is five definitions. You need to match the correct key word to the right definition. Pause the lesson now to do this. Restart when you're ready to go through the answers. So the first one, allele. An allele is different versions of the same gene. Homozygous. Homozygous means alleles for a characteristics are the same. Remember homo means same. Heterozygous. Is when alleles for characteristic are different. Remember, hetero means different. Genotype. That is the pair of alleles. And finally phenotype, that is the physical characteristic that is displayed. Remember, pheno is physical, a physical characteristic. Let's have a quiz. Which characteristic is only controlled by genes? Looks like weight, height or hair colour. Well done blood type. The other three options will be influenced by your genes. However, they can change or fluctuate depending on your environment. Which of the following genotypes are heterozygous? There's two of them. Well done, remember hetero means different. And these two alleles are different. One is capital and one is lowercase. Which of the following gene types are homozygous? Fantastic. Remember, homo mean same, and both of these genotypes have the same allele. Okay, so first I'm going to give you a little recap on how to use Punnett squares. And then you're going to have a go at doing some on your own. So I'd like you copy and complete the Punnett Square and work out the probabilities of each genotype and phenotype. So, like I said, I'm going to do this one together. So you don't need to make any notes on this one, just watch and listen. So that I've got a code for the different alleles code form. So big B goes for brown eyes and little b goes for blue eyes. And this is the Punnett Square I've been given. So here we're going to work out the probability of when two people with brown eyes, with heterozygous alleles reproduce. So I'm going to fill in that Punnett Square now. In the first section is going to be big B, big B, cause that person would inherit the dominant allele from both parents. The second one is going to be big B little b. They've inherited one dominant allele and one recessive allele. Next is going to be big B little b. Again, they've inherited one dominant allele and one recessive allele and finally we're going to get little b little b. And that person has inherited the recessive allele from both parents. So we're working out the probability of each genotype. So let's have a look at the possible genotypes we could have. We could have big B big B, and we've got one of those. So the probability there is one in four, we could have big B, little b, and we've got two of those. So the probability there is two out of four, which cancels to a half. And finally, we've got little b little b, and there's one of those. So the probability of that is one out of four. Now looking at the phenotypes, remember, phenotype means the physical characteristic, so the genotypes there that go for brown eyes are Big B Big B, and Big B little b. Because brown eyes are dominance, so if that allele is present, that characteristic will show up. So for brown eyes, three out of the four, code for brown eyes, so the probability of having brown eyes is three out of four. The probability of having blue eyes is one out of four. Because the only genotype that codes for blue eyes is little b little b. You are now going to have a go at copying and completing a Punnett Square. Then you're going to work out the probabilities of the different genotypes and phenotypes. Here's the information that you need. Firstly, complete that Punnett Square. Pause the lesson if you need to. However, I will leave a little bit of time for you to complete it. I'm going to reveal the answers now. Check your Punnett Square against mine. Now we need to work out the genotypes. There's only one type of genotype present here. and that is big W little w. So the probability is 100%. So if the phenotype remember the capital W is the dominant allele and that codes for white fur. So four out four are going to have white fur, which is equal to 100%. This is the final Punnett square that I would like you to have a go at. Pause lesson now and have a go at completing it on your own. Try to work out the probabilities of the different genotypes and the different phenotypes. I know that's quite a lot, but you can do it. Okay, so let's see what you got. So in the Punnett Square, this should have been your answers. Check yours against mine. These are the possible genotypes with their probabilities. And these are the possible phenotypes with their probabilities as well. Check your answers against mine, and if they're not quite the same, rewind to when I talk through how to fill in the Punnett Square and then work out the genotypes and phenotypes. Then have another go. So we're now on to the final task. In the left hand side of this table, there was three statements that are incorrect. What I would like you to do is correct those statements and put them in the right hand side of your table. Pause the lesson now and complete this task. Restart the lesson when you're ready to go through the answers. Here's that table completely filled in. Check your answers against mine and pause the lesson if you need to, to mark your work. Remember, fill in any bits that you missed. And that's it. We've come to the end of the whole of the biological systems and processes topic. Well done for getting this far. I'm really proud of you. So for the final time, I'd like you to now go and complete the exit quiz. Thanks for watching. Bye.

This quiz will test your knowledge from this topic.

What is the addictive substance in cigarettes?

Why might a pregnant woman decide not to drink alcohol?

What is a gene?

What shape is DNA?

Which of the following scientists did not receive a Nobel Prize for their work towards DNA discovery?

Review two

Recall key terms, definitions and structures related to biological systems and processes

Use scientific language accurately to correct statements

Review and consolidate knowledge from the biological systems and processes unit

In this lesson we will recall key terms, definitions and structures related to biological systems and processes
We will also use scientific language accurately to correct statements and review and consolidate our knowledge.

Lesson overview:Review Two

Biological systems and processes: