Consider statements about genetics: 1. DNA is double-stranded. 2. RNA contains thymine. 3. Genes are located on chromosomes. Which are correct? MCQ with Answer and Explanation

Explanation:
Archaeopteryx lithographica, a Jurassic fossil, exhibits features of both reptiles (teeth, bony tail, claws) and birds (feathers, wings), supporting the theory that birds evolved from theropod dinosaurs. It is a classic transitional fossil. Tiktaalik links fish and amphibians, cynodonts link reptiles and mammals.

Explanation:
Meiosis is characterized by two successive divisions producing haploid gametes, and involves genetic recombination through crossing over during prophase I. Mitosis produces identical diploid cells with one division. Crossing over and independent assortment generate genetic variation. Therefore, crossing over is unique to meiosis.

Explanation:
Phycocyanin is a blue phycobiliprotein pigment present in cyanobacteria (blue-green algae), along with chlorophyll a. Phycoerythrin is red, carotene orange. Phycobilins are accessory pigments that capture light energy for photosynthesis.