A tap roots is always

Options

A. `+` Vely geotropic and + vely hydrotropic
B. `+` Vely phototropic and + vely hydrotropic
C. `-` Vely geotropic and + vely hydrotropic
D. `-` Vely hydrotropic and + vely geotropic

Answer

To solve the question regarding the characteristics of tap roots, we can break down the information step by step.

### Step-by-Step Solution:

1. **Understanding Tap Roots**:
- Tap roots are the primary root system that grows vertically downward from the seedling. They originate from the radical (the part of the seed that develops into the root).

2. **Characteristics of Tap Roots**:
- Tap roots are designed to anchor the plant and absorb water and nutrients from deeper soil layers.

3. **Geotropism**:
- Geotropism refers to the growth of plant parts in response to gravity. Positive geotropism means growth towards the gravitational pull, which is downward in the case of roots.
- Since tap roots grow downward, they exhibit positive geotropism.

4. **Hydrotropism**:
- Hydrotropism is the growth of plant roots in response to moisture. Positive hydrotropism means that the roots grow towards areas of higher moisture content.
- Tap roots grow towards moisture in the soil, indicating that they are positively hydrotropic.

5. **Evaluating the Options**:
- Option 1: Positively geotrophic and positively hydrotrophic - This is correct as explained above.
- Option 2: Positively phototropic and positively hydrotrophic - This is incorrect because phototropism refers to growth towards light, which is not applicable to roots.
- Option 3: Negatively geotrophic and positively hydrotrophic - This is incorrect as tap roots are positively geotropic.
- Option 4: Negatively hydrotrophic and positively geotropic - This is incorrect because tap roots are positively hydrotropic.

6. **Conclusion**:
- The correct answer is option 1: A tap root is always positively geotrophic and positively hydrotrophic.