To solve the question, we will analyze each part step by step and fill in the blanks with the appropriate terms based on the information provided in the video transcript.
### Step-by-Step Solution:
**(a)**
1. **(i)** The tolerance level of receptors present in our body **decreases** with repeated use of drugs.
- **Hint:** Tolerance refers to the body's adaptation to a drug, leading to a decreased response over time.
2. **(ii)** Smoking increases **CO** (carbon monoxide) and reduces the concentration of **CO2** (carbon dioxide) in blood.
- **Hint:** Smoking introduces harmful substances like carbon monoxide, which competes with oxygen in the blood.
3. **(iii)** Cannabinoid receptors are primarily present in the **brain**.
- **Hint:** The brain is a major site for cannabinoid receptors, particularly CB1 receptors.
4. **(iv)** Morphine is a very effective **hallucinogen** and **depressant**.
- **Hint:** Morphine is primarily known for its pain-relieving properties but can also have depressant effects.
5. **(v)** Opioids are extracted from **latex** of the poppy plant.
- **Hint:** Latex is the milky fluid from the poppy plant that contains alkaloids like morphine.
**(b)**
1. **(i)** The tolerance level of receptors present in our body **increases** with repeated use of drugs.
- **Hint:** Chronic exposure to drugs leads to increased tolerance, making the body require more of the drug for the same effect.
2. **(ii)** Smoking increases **CO** and reduces the concentration of **haemoglobin-bound oxygen** in blood.
- **Hint:** Carbon monoxide binds with hemoglobin more effectively than oxygen, reducing oxygen transport.
3. **(iii)** Cannabinoid receptors are primarily present in the **brain**.
- **Hint:** The brain has a high concentration of cannabinoid receptors.
4. **(iv)** Morphine is a very effective **sedative** and **painkiller**.
- **Hint:** Morphine is used to relieve pain and calm the nervous system.
5. **(v)** Opioids are extracted from **latex** of the poppy plant.
- **Hint:** The latex contains the active compounds used for medicinal purposes.
**(c)**
1. **(i)** The tolerance level of receptors present in our body **decreases** with repeated use of drugs.
- **Hint:** Tolerance can lead to decreased sensitivity to the drug.
2. **(ii)** Smoking increases **CO** and reduces the concentration of **haemoglobin-bound oxygen** in blood.
- **Hint:** Smoking introduces carbon monoxide, which affects oxygen transport.
3. **(iii)** Cannabinoid receptors are primarily present in the **brain**.
- **Hint:** The brain is the main site for cannabinoid action.
4. **(iv)** Morphine is a very effective **sedative** and **painkiller**.
- **Hint:** Morphine's primary use is in pain management.
5. **(v)** Opioids are extracted from **latex** of the poppy plant.
- **Hint:** The latex is the source of morphine and other opioids.
**(d)**
1. **(i)** The tolerance level of receptors present in our body **increases** with repeated use of drugs.
- **Hint:** Increased tolerance can lead to higher doses being required.
2. **(ii)** Smoking increases **CO** and reduces the concentration of **haemoglobin-bound oxygen** in blood.
- **Hint:** Carbon monoxide from smoking impacts oxygen delivery in the body.
3. **(iii)** Cannabinoid receptors are primarily present in the **heart**.
- **Hint:** While the brain has many receptors, the heart also has cannabinoid receptors that play a role in cardiovascular function.
4. **(iv)** Morphine is a very effective **sedative** and **painkiller**.
- **Hint:** Morphine is widely recognized for its analgesic properties.
5. **(v)** Opioids are extracted from **resin** of the poppy plant.
- **Hint:** Resin refers to the sticky substance that can also contain active compounds.
### Final Answers:
- (a) (i) decreases, (ii) CO, CO2, (iii) brain, (iv) hallucinogen, depressant, (v) latex
- (b) (i) increases, (ii) CO, haemoglobin-bound oxygen, (iii) brain, (iv) sedative, painkiller, (v) latex
- (c) (i) decreases, (ii) CO, haemoglobin-bound oxygen, (iii) brain, (iv) sedative, painkiller, (v) latex
- (d) (i) increases, (ii) CO, haemoglobin-bound oxygen, (iii) heart, (iv) sedative, painkiller, (v) resin
