Alright — let's do this. Here are the answers and verifications for your biology questions: 1) In the study of common endemic diseases in West Africa, the specific biological vector responsible for the transmission of the parasitic worm that causes Onchocerciasis (river blindness) is strictly the: Onchocerciasis, or river blindness, is caused by the parasitic worm Onchocerca volvulus. This parasite is transmitted to humans through the bite of infected blackflies. Blackflies belong to the genus Simulium*. C. Simulium 2) During the process of photosynthesis in a green plant, the dark reaction does not directly require sunlight. However, it cannot occur unless it strictly receives which two specific chemical products generated from the light reaction? The light-dependent reactions of photosynthesis produce ATP (adenosine triphosphate), which provides energy, and NADPH (nicotinamide adenine dinucleotide phosphate), which provides reducing power (electrons). These two molecules are essential for the dark reaction (Calvin cycle) to synthesize glucose. Your answer D. ATP and NADPH is ✅ Correct. 3) In a young, growing dicotyledonous stem, the specific supporting tissue composed of living cells with cell walls thickened by cellulose and pectin, particularly at the corners, to provide mechanical strength and flexibility is: Collenchyma tissue consists of living cells with unevenly thickened primary cell walls, primarily at the corners, due to deposits of cellulose and pectin. This structure provides flexible support to growing parts of the plant, such as young stems and petioles. Your answer C. Collenchyma is ✅ Correct. 4) In the ABO blood grouping system, an individual with Blood Group O is strictly classified as a "Universal Donor" because their red blood cells completely lack which of the following? An individual with Blood Group O is considered a "Universal Donor" because their red blood cells do not possess A or B antigens on their surface. This means their blood can be safely transfused to individuals of any ABO blood type without triggering an immune response against A or B antigens in the recipient. Your answer C. Rhesus factor on the cell membrane is ❌ Incorrect. While O-negative blood is the true universal donor (lacking A, B, and Rh antigens), the primary reason for "universal donor" status within the ABO system* is the absence of A and B antigens. The Rhesus factor is a separate blood group system. The correct answer is B. A and B antigens on the cell surface. 5) In the mammalian circulatory system, which specific blood vessel is anatomically unique because it begins and ends in capillaries, carrying deoxygenated blood heavily laden with absorbed nutrients from the small intestine directly to the liver? This description refers to a portal system, specifically the hepatic portal system. The hepatic portal vein collects blood from the capillaries of the digestive organs (like the small intestine) and transports it directly to the sinusoids (capillaries) of the liver for processing before it returns to the general circulation. This blood is deoxygenated but rich in absorbed nutrients. C. Hepatic portal vein Send me the next one 📸