Consider statements about the small intestine: 1. Villi increase the surface area for absorption. 2. The duodenum receives bile and pancreatic juice. 3. The ileum is the first part of the small intestine. Which are correct? MCQ with Answer and Explanation

Explanation:
In 1944, Oswald Avery, Colin MacLeod, and Maclyn McCarty conducted a landmark experiment building on Griffith's transformation experiment. They purified various macromolecules (DNA, RNA, proteins, lipids) from the virulent S strain of Streptococcus pneumoniae and tested which one could transform the non-virulent R strain into the virulent form. They found that only DNA could cause transformation, and this activity was destroyed by DNase but not by RNase or proteases. This provided the first strong, direct evidence that DNA, not protein, is the genetic material.

Explanation:
The hepatic lobule is the basic structural and functional unit of the liver, consisting of plates of hepatocytes radiating from a central vein. Bile canaliculi, sinusoids, and portal triads are key features. Nephrons are kidney units, alveoli lung units, islets pancreatic endocrine units.

Explanation:
The human skull consists of 22 bones (8 cranial and 14 facial). The femur (thigh bone) is the longest and strongest bone in the human body. Humans have 12 pairs of ribs; the first 7 are true ribs (direct attachment), next 3 are false ribs (indirect), and last 2 are floating. All statements are anatomically correct.