Minimum number of barrier iMs / are present between foetal and maternal blood?

Options

A. pig
B. human
C. goat
D. cow

Answer

To determine the minimum number of placental barriers present between fetal and maternal blood among the given options (pig, human, goat, cow), we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Concept of Placental Barriers**:
- The placental barrier refers to the structures that separate maternal blood from fetal blood in the placenta. These barriers are crucial for the exchange of nutrients, gases, and waste products between the mother and the fetus.

2. **Identify the Number of Barriers in Different Species**:
- Research indicates that different mammals have varying numbers of placental barriers. The typical range is from 3 to 6 barriers.
- For the species in the options:
- **Pig**: 6 placental barriers
- **Goat**: 6 placental barriers
- **Cow**: 6 placental barriers
- **Human**: 3 placental barriers

3. **Compare the Numbers**:
- From the above information, we can see that pigs, goats, and cows each have 6 placental barriers, while humans have only 3.

4. **Determine the Minimum**:
- Since humans have the least number of placental barriers compared to the other options, we conclude that humans have the minimum number of barriers.

5. **Final Answer**:
- Therefore, the answer to the question is **humans**, as they have the minimum number of placental barriers (3).