2009 BIOLOGY PAPER 2 G12 Q3 ENDOCRINE GLANDS

追加: 2026-05-24

[00:00:03]Hello, good day viewers. I welcome you all to this biology presentation. So, in this presentation, we are going to answer our question three A and B. So, question three A reads, "Complete the table 3.1 by filling in the blank spaces." So, we have the blank spaces here. So, in column one, we have hormone. And in column two, we have the source where these hormones are coming from. And in column three, we have the action, meaning we have the the roles or the functions of these hormones. So, in A1, we have uh the source, which is the ovary, then the hormone we don't know. Then this hormone, it begins rebuilding the lining of the uterus. So, what is the name of the hormone that is produced by the ovary or the one that comes from the ovary and it begins rebuilding the lining of of the uterus? So, the ovary, they actually produce two hormones. We have the estrogen hormone and the progesterone hormone. Okay? So, the hormone that will begin the that begins rebuilding the lining of the uterus is the estrogen hormone. So, here I'm going to write estrogen hormone.

[00:01:11]Okay. So, this is our answer.

[00:01:14]Okay, we now move on to question A2. So, in the hormone here, we have thyroxine hormone, which is produced by the thyroid gland. Then we are looking for the action of this hormone.

[00:01:25]So, when you look at the thyroxine hormone, this is the hormone that controls the body's what?

[00:01:32]Metabolism. Most of the chemical reactions that takes place in the body, they are normally controlled by the thyroxine hormone. Meaning that it controls how fast the food is changed into energy. And it also supports growth and what? Development. Apart from that, it also helps to control the body temperature and the heartbeat. So, the way you can write the function of this hormone, you can say it is stimulates the metabolic rate of what? Of cells.

[00:01:58]So, you can say it stimulates It is stimulates Okay? The metabolic It is stimulates the metabolic It is stimulates the metabolic Okay? The metabolic rate of cells.

[00:02:29]So, this is how you can write your answer. It is stimulates the metabolic rate of cells. So, this is the function of the thyroxine hormone.

[00:02:38]Now, we move on to the last part, which is A3. Here, under hormone we have nothing. And this hormone is coming from where? The adrenal gland. Okay? So, what is the name of this hormone which comes from the adrenal gland? And what is its action? So, the name of the hormone that is produced by the adrenal gland This hormone is called the adrenaline hormone, okay? So, this is the adrenaline This is the adrenaline hormone. Now, this adrenaline hormone, it actually just prepare the body for emergency situations, okay? Or when there is a sudden action. Meaning that when you are just sitting down, then someone comes and uh uh talks to you without knowing in a louder voice, your heart is going to pump fast. So, the your body is going to be prepared for that emergency which has occurred through this adrenaline what? Hormone.

[00:03:29]Okay? Apart from that, I'm saying it increases the heartbeat, the breathing rate, and the blood what? Pressure, and the energy supply to the muscles. So, this hormone is sometimes called the fight and flight response response because of those uh things that it controls. So, to write our answer over the action of this hormone, which is the adrenaline hormone, we can just say it uh prepares the body against emergencies. They will mark you, okay?

[00:03:58]Or you can say it increases the speed and force of the heartbeat to prepare the body to deal with what? Danger. They will mark you even that answer. So you can say this one, you can say to prepare This is the function or the action to prepare the body to prepare the body for emergence to prepare the body for emergence situations.

[00:04:33]To prepare the body for emergency situations.

[00:04:38]Or if you don't want to to say that you can say or sudden action.

[00:04:48]Or sudden action. So this is the function of the adrenaline hormone.

[00:04:55]So we are done answering this question.

[00:04:58]We are done answering this question. I believe we can now continue. We look at question B. So let us now move on. We go to question B. So under question B I'm sure you're able to see the question right here. So this is the question. So the question reads What happens to the hormones after completing their action in target organs? So here we need to explain what will happen to the hormones after completing their actions in target what?

[00:05:30]Organs. In target organs. And this question was just carrying a two marks, okay? And this question was carrying two marks. So what happened to the hormone after they complete their actions in the target organ is that they are broken down and removed from the body. And they get destroyed by the liver and they will be filtered out by the kidneys. So, the waste products are and then expected or excreted in the urine, okay? Or other body wastes. So, this now it helps the correct balance of hormones in the body.

[00:06:02]So, here what happens to hormones after completing their action in target organs, okay? So, or you say they are they are removed.

[00:06:16]Okay?

[00:06:20]We'll say they are removed.

[00:06:25]They are removed.

[00:06:28]And broken down. I think we can start with the broken down. You can say they are broken down.

[00:06:37]They are broken down.

[00:06:40]They are broken down and removed.

[00:06:45]They are broken down and removed from the body.

[00:06:51]Removed from the body.

[00:06:57]And get destroyed.

[00:07:06]And get destroyed by the liver.

[00:07:15]So, this is what is going to happen to to the hormones. They are broken down and removed from the body and get destroyed by by the liver. So, if you answer they get destroyed by the liver, they will mark you now. You look at the number of marks. It's carrying two marks, so you can explain there. Okay?

[00:07:32]You can explain. So, this is what happens to the hormones after completing their action in the target what? Organs.

[00:07:40]I I believe it's it's clear. We can now move on. We look at another question. All right. So, now we have come to question C right here.

[00:07:51]So, our question C reads State two ways in which hormones and nerve impulses differ in controlling body processes. So, here we need to state how hormones differ with nerve impulses in controlling body processes. So, one of the the ways is that one of the ways is that the the hormones they affect many organ systems at once, okay? So, here we can say hormones hormones often affect many many organ systems many organ systems at once.

[00:08:47]Wow, okay?

[00:08:49]Hormones affect many organ systems at once, while nerve impulses while nerve impulses are specific.

[00:09:04]So, them they are specific and precise, okay?

[00:09:08]They are specific and precise.

[00:09:13]So, this is the first difference.

[00:09:17]Hormones often affect many organ systems at once, while nerve impulses are specific and what? Precise. So, if you don't want to say that, you can also say hormones control body processes slowly, okay?

[00:09:35]We can say hormones control body processes slowly.

[00:09:49]Hormones control body processes slowly.

[00:09:53]Okay?

[00:09:54]And and their and their effects and their effects last longer.

[00:10:15]Whereas whereas nerve impulses So, if hormones are are able to control body processes slowly, it means that the nerve impulses, them, they control the body processes quickly. Okay? The whereas nerve impulses whereas nerve impulses nerve impulses control body processes control body processes quickly.

[00:10:56]Control body processes quickly.

[00:10:59]Okay?

[00:11:00]So, I hope this point is clear. They control body processes quickly and their effects Remember the effects of hormones, it takes longer. And their effects Okay?

[00:11:15]And their effects last for last for a short time. Okay? For a short time.

[00:11:25]That is another difference.

[00:11:28]And their effects last for a short time.

[00:11:31]So, here we have said, "The hormones control body processes slowly and their effects last longer, whereas nerve impulses control body processes quickly and their effects last for a short time." If you don't want to uh to say that, there's another reason that you can give. I believe for now this question you have fully answered it and it's clear. We can now uh end our short presentation. So, thank you so much, everybody. We've come to the end of our short presentation.