Which radioactive isotope is commonly used for dating relatively recent fossils (up to about 50,000 years old)? MCQ with Answer and Explanation

Explanation:
Aspergillosis is an opportunistic fungal infection, often affecting the lungs, caused by inhalation of Aspergillus spores. Candidiasis is by Candida, ringworm by dermatophytes, histoplasmosis by Histoplasma.

Explanation:
The lymphatic system drains excess tissue fluid (lymph) back to the venous blood. Blood circulation is the cardiovascular system; lymph nodes filter lymph; thymus is a primary lymphoid organ.

Explanation:
Collenchyma cells have unevenly thickened walls, providing mechanical support and flexibility to growing plant parts like stems. Sclerenchyma consists of dead cells with heavily lignified, thick walls, providing rigid strength to plant parts. Parenchyma cells are living, thin-walled, and serve as the primary packing tissue, storing food, water, and air. All three statements are correct.