Assertion (A): Cuscuta is a parasitic plant. Reason (R): It has chlorophyll and can photosynthesize its own food. MCQ with Answer and Explanation

Explanation:
Stomata are surrounded by two kidney-shaped guard cells in dicots (dumb-bell-shaped in grasses) that control pore opening/closing via turgor pressure changes. When guard cells absorb water and become turgid, the stomatal pore opens; when flaccid, it closes. This process is influenced by light, CO₂ concentration, and abscisic acid (ABA). Stomata are critical for gas exchange and transpiration.

Explanation:
Salivary amylase (ptyalin) initiates starch digestion in the mouth, hydrolyzing it into maltose and dextrins. Pepsin digests protein, lipase fats, rennin curdles milk. Amylase works optimally at neutral pH.

Explanation:
A gene is a specific sequence of nucleotides in DNA that serves as the fundamental unit of heredity, typically coding for a specific protein or RNA molecule. Alleles are different versions or alternative forms of the same gene that occupy the same locus on homologous chromosomes and determine variations in a trait. The genotype is the genetic makeup of an organism, while the phenotype is the observable physical or biochemical characteristics. Thus, statements 1 and 2 are correct.