In plants, a low concentration of N, S and Mo causes

Options

A. inhibition of cell division
B. delay in flowering
C. death of tissue
D. both A and B

Answer

To solve the question regarding the effects of low concentrations of nitrogen (N), sulfur (S), and molybdenum (Mo) in plants, we can break it down into the following steps:

### Step 1: Understand the Role of Nitrogen
- Nitrogen is a crucial component of chlorophyll, which is essential for photosynthesis.
- It is also a key element in the formation of amino acids, which are the building blocks of proteins.

**Hint:** Consider how nitrogen deficiency affects chlorophyll production and protein synthesis.

### Step 2: Analyze the Effects of Low Nitrogen Concentration
- A deficiency in nitrogen leads to reduced chlorophyll production, which can inhibit photosynthesis.
- This results in delayed flowering because flowering is often triggered by the energy produced during photosynthesis.

**Hint:** Think about the relationship between chlorophyll and flowering in plants.

### Step 3: Understand the Role of Sulfur
- Sulfur is important for protein synthesis and is a component of certain amino acids and vitamins.
- It also plays a role in chlorophyll formation.

**Hint:** Reflect on how sulfur deficiency could impact protein synthesis and chlorophyll levels.

### Step 4: Analyze the Effects of Low Sulfur Concentration
- Low sulfur levels can lead to poor protein synthesis, which in turn can inhibit cell division.
- Similar to nitrogen, a lack of sulfur can also delay flowering due to insufficient chlorophyll production.

**Hint:** Consider how protein synthesis is linked to cell division and overall plant growth.

### Step 5: Understand the Role of Molybdenum
- Molybdenum is essential for the conversion of nitrates to nitrites and subsequently to ammonia, which is vital for nitrogen metabolism.
- It also aids in the conversion of phosphates to organic phosphates.

**Hint:** Think about how molybdenum contributes to nitrogen fixation and nutrient availability.

### Step 6: Analyze the Effects of Low Molybdenum Concentration
- While molybdenum is important for nitrogen metabolism, its deficiency primarily affects nitrogen utilization rather than directly causing cell division inhibition or delayed flowering.
- Therefore, its role is less direct compared to nitrogen and sulfur.

**Hint:** Focus on the specific functions of molybdenum and how they differ from those of nitrogen and sulfur.

### Step 7: Combine the Effects
- Given that both nitrogen and sulfur deficiencies lead to inhibition of cell division and delay in flowering, we can conclude that the primary effects of low concentrations of N, S, and Mo in plants are:
- Inhibition of cell division
- Delay in flowering

### Step 8: Choose the Correct Option
- Based on the analysis, the correct answer is "both A and B," which corresponds to the inhibition of cell division and delay in flowering.

**Final Answer:** Both A and B (inhibition of cell division and delay in flowering).