Choose the correct order of events in the Nitrogen Cycle.

Let's go through these biology questions.

1. The point of attachment of the leaf to the stem is the:

   • B. Node. A node is the point on a stem where a leaf, branch, or flower is attached.

2. The contractile vacuole in Amoeba helps in:

   • D. Osmoregulation. The contractile vacuole actively pumps out excess water from the Amoeba's cytoplasm, preventing it from bursting due to osmosis.

3. Choose the correct order of events in the Nitrogen Cycle.

   • D. Nitrogen In the air → Bacteria fix Nitrogen → Animals get Nitrogen from plants → Animals die and decompose. This sequence correctly illustrates nitrogen fixation, assimilation by plants and animals, and decomposition.

4. A solution obtained from crushed germinating bean seeds was tested with Millon's reagent and a red colour was observed. This indicates the presence of:

   • A. Proteins. Millon's reagent is used to detect the presence of proteins, and a red color indicates a positive result.

5. Which part of the alimentary canal produces bile?

   • B. Liver. The liver produces bile, which is then stored in the gall bladder before being released into the duodenum.

6. Which layer of the skin produces melanin?

   • B. Malpighian layer. The Malpighian layer (also known as the stratum basale and stratum spinosum) contains melanocytes, which are cells responsible for producing melanin.

7. What structure protects the lizard's body from mechanical injury?

   • A. Scales. Lizards, being reptiles, have a body covered in scales that provide protection against physical damage and desiccation.

8. The diagram below is that of a plant cell. Which of the numbered structures contain chlorophyll?

   • C. 3. Structure 3 points to a chloroplast, which is the organelle in plant cells that contains chlorophyll and is the site of photosynthesis.

9. The part of the eye responsible for image formation is the:

   • C. Retina. The retina is the light-sensitive layer at the back of the eye that contains photoreceptor cells (rods and cones) responsible for detecting light and forming an image.