Assertion (A): The bacterial cell wall is composed of peptidoglycan. Reason (R): Peptidoglycan provides structural strength and prevents osmotic lysis. MCQ with Answer and Explanation

Explanation:
Genetics is the science of heredity and variation, explaining how traits are passed from parents to offspring and why individuals differ. Ecology studies organisms and environment, embryology deals with development, paleontology with fossils. Gregor Mendel is the father of genetics. The term 'genetics' was coined by William Bateson.

Explanation:
Genotype refers to the specific set of genes (allelic constitution) of an individual, e.g., TT, Tt, or tt for a trait. Phenotype is the observable characteristic, karyotype is the chromosome complement, allele is a variant form of a gene. The genotype determines the potential phenotype.

Explanation:
Prophase I of meiosis is divided into five sub-stages: leptotene, zygotene, pachytene, diplotene, and diakinesis. Crossing over, the exchange of genetic material between non-sister chromatids of homologous chromosomes, occurs specifically during the pachytene stage at structures called recombination nodules.