Alexander Fleming discovered the first antibiotic, Penicillin, from: MCQ with Answer and Explanation

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.

Explanation:
Primase is an RNA polymerase that synthesizes short RNA primers complementary to the DNA template, providing a free 3'-OH for DNA polymerase to begin synthesis. Helicase unwinds, polymerase extends, ligase joins.

Explanation:
Pneumatophores are negative geotropic, spongy roots that grow upwards out of the water or mud to obtain oxygen in anaerobic, waterlogged soils. They are a characteristic adaptation of mangrove plants like Rhizophora (mangrove). Orchids have epiphytic aerial roots, Cuscuta has parasitic haustoria, and Nepenthes has modified pitcher leaves for insectivory.