Which of the following glands is/are heterocrine gland(s)?
( a ) Pancreas ( b ) Sweat gland
( c ) Gonads ( d ) Mammary gland

Options

A. (a) & ( c ) Only
B. (a) , (b) & ( c ) Only
C. (b) & (d) Only
D. (a) , (b) , ( c ) & (d)

Answer

To determine which glands from the given options are heterocrine glands, we need to understand the definitions and functions of the glands listed.

### Step-by-Step Solution:

1. **Define Heterocrine Glands**:
- Heterocrine glands are those that have both exocrine and endocrine functions. This means they secrete substances through ducts (exocrine) and also release hormones directly into the bloodstream (endocrine).

2. **Analyze Each Option**:
- **(a) Pancreas**:
- The pancreas has both functions. It secretes digestive enzymes (exocrine function) through the pancreatic duct into the small intestine and also produces hormones like insulin and glucagon (endocrine function) that regulate blood sugar levels.
- **(b) Sweat Gland**:
- Sweat glands are purely exocrine. They secrete sweat through ducts to the surface of the skin for thermoregulation and excretion. They do not have an endocrine function.
- **(c) Gonads**:
- Gonads (testes and ovaries) also have both functions. They produce gametes (sperm and ova) as an exocrine function and secrete hormones like testosterone and estrogen (endocrine function) that regulate reproductive processes.
- **(d) Mammary Gland**:
- Mammary glands are purely exocrine. They produce milk for nursing infants and release it through ducts. They do not secrete hormones directly into the bloodstream.

3. **Conclusion**:
- Based on the analysis, the glands that are heterocrine are the **Pancreas (a)** and **Gonads (c)**. Therefore, the correct answer is **(a) Pancreas and (c) Gonads**.

### Final Answer:
The heterocrine glands from the options provided are **(a) Pancreas and (c) Gonads**.