Explore core concepts from plant biotechnology, plant biochemistry, crop physiology, genetics, and agricultural practices as outlined in the entrance exam syllabi. This quiz is designed for those seeking foundational knowledge in plant science and related agricultural disciplines.
Which nutrient is primarily responsible for promoting leaf and stem growth in plants, with deficiency often causing yellowing of older leaves?
Explanation: Nitrogen is essential for the synthesis of chlorophyll and amino acids, supporting vigorous leaf and stem growth. Deficiency typically yellow older leaves first. Phosphorus mainly supports root development and energy transfer, potassium aids in water regulation and disease resistance, while calcium is involved in cell wall structure but does not directly cause the described symptoms when deficient.
Which molecule serves as the primary carrier of genetic information in both plant and animal cells?
Explanation: Deoxyribonucleic acid (DNA) is the main molecule that stores and transmits genetic information in most living organisms. Glucose is a sugar used for energy, amino acids are building blocks of proteins, and starch is a storage form of carbohydrate, none of which serve as genetic material.
Which photosynthetic pathway is common in tropical plants like maize and helps reduce photorespiration under high temperature and light intensity?
Explanation: The C4 pathway, found in crops such as maize, effectively minimizes photorespiration and improves efficiency under intense light and high temperatures. The C3 pathway is more common in temperate crops and is less efficient in such conditions. The CAM pathway is typical for succulents, while 'NADP pathway' is an incorrect or vague term not directly associated with photosynthesis types.
What is a key distinguishing feature of fungi compared to bacteria, mycoplasmas, and viruses?
Explanation: Fungi are unique among these groups for being eukaryotic, containing membrane-bound organelles such as nuclei and mitochondria. All organisms listed have genetic material, but only plants and some microorganisms can photosynthesize; fungi cannot. Fungi may be multicellular (e.g., molds) or unicellular (e.g., yeast), so the last option is incorrect.
In Mendel’s experiments, what is the expected phenotypic ratio among offspring in a monohybrid cross between two heterozygous pea plants?
Explanation: A monohybrid cross between two heterozygous individuals typically yields a 3:1 phenotypic ratio, with three showing the dominant trait and one showing the recessive trait. A 1:1 ratio is expected in certain test crosses, 9:3:3:1 is for dihybrid crosses, and 2:2 is not a conventional outcome in Mendel’s basic experiments.