Read of the following statements:-
(a) Insect resistance in crop plants may be due to morphological, biochemical or physiological characteristics.
(b) Hairy leaves in cotton are resistant to cereal jassids.
(c) Smooth leaves and nectar-less cotton varieties do not attract bollworms.
(d) In maize, high asparatic acids, low nitrogen and sugar leads to resistance to stemborers.
Choose correct statements :-

Options

A. a,c
B. a,b,c
C. a,c,d
D. a,b,c,d

Answer

To determine the correct statements regarding insect resistance in crop plants, let's analyze each statement step by step:

### Step 1: Analyze Statement (a)
**Statement:** Insect resistance in crop plants may be due to morphological, biochemical or physiological characteristics.
**Analysis:** This statement is true. Insect resistance can indeed arise from various characteristics of the plants, including their physical structure (morphological), chemical processes (biochemical), or overall functioning (physiological).
**Conclusion:** Statement (a) is correct.

### Step 2: Analyze Statement (b)
**Statement:** Hairy leaves in cotton are resistant to cereal jassids.
**Analysis:** This statement is also true. Hairy leaves can deter insect pests like cereal jassids due to their texture, making it difficult for these pests to feed on the leaves.
**Conclusion:** Statement (b) is correct.

### Step 3: Analyze Statement (c)
**Statement:** Smooth leaves and nectar-less cotton varieties do not attract bollworms.
**Analysis:** This statement is correct as well. Bollworms are attracted to nectar, and by having smooth leaves and lacking nectar, these cotton varieties can effectively avoid attracting bollworms.
**Conclusion:** Statement (c) is correct.

### Step 4: Analyze Statement (d)
**Statement:** In maize, high asparatic acids, low nitrogen and sugar leads to resistance to stemborers.
**Analysis:** This statement is true. Genetic modifications that increase asparatic acid levels and decrease nitrogen and sugar content can enhance resistance to stemborers in maize.
**Conclusion:** Statement (d) is correct.

### Final Conclusion
After analyzing all four statements, we find that all of them are correct. Therefore, the answer to the question is that statements A, B, C, and D are correct.