Consider statements about scientists: 1. Carolus Linnaeus is the father of taxonomy. 2. Louis Pasteur is the father of microbiology. 3. Gregor Mendel is the father of genetics. Which are correct? MCQ with Answer and Explanation

Explanation:
Matthew Meselson and Franklin Stahl, in 1958, used density gradient centrifugation of E. coli grown in N¹⁵ medium to prove that DNA replication is semi-conservative: each new DNA molecule consists of one old and one new strand. Watson and Crick proposed the double helix, Hershey-Chase confirmed DNA as genetic material, Chargaff formulated base pair rules.

Explanation:
The pineal gland, a small endocrine gland located in the epithalamus of the brain, is often called the 'biological clock' or the 'third eye' in some lower vertebrates. Its primary function in humans is to secrete the hormone melatonin. Melatonin production is regulated by the light-dark cycle (circadian rhythm); it is produced in higher amounts during the night and suppressed by light. Melatonin helps regulate sleep-wake cycles, seasonal reproductive functions, and metabolism.

Explanation:
Southern blotting, named after its inventor Edwin Southern, is a laboratory method used to detect specific DNA sequences in a complex DNA sample. The process involves digesting DNA with restriction enzymes, separating the fragments by gel electrophoresis, transferring (blotting) them onto a nylon or nitrocellulose membrane, and then hybridizing the membrane with a labeled, complementary DNA or RNA probe. Northern blotting detects RNA, and Western blotting detects proteins.