WAEC SSCE Agricultural Science
Study notes for Classification of crops — part of the WAEC SSCE Agricultural Science syllabus. 3 learning objectives with explanations and exam tips.
Crops are grouped according to what they're used for, and this helps farmers decide what to plant. Cereals are grains like maize, rice, and millet that give us carbohydrates for energy. Pulses are legumes such as beans and groundnuts that provide protein for our bodies. Roots and tubers like cassava, yam, and potatoes store nutrients underground and are staple foods in Nigeria. Vegetables include leafy plants like spinach and fruiting plants like tomatoes that give us vitamins and minerals. Each group serves different nutritional purposes, which is why a balanced diet contains all of them. For example, a typical Nigerian meal of jollof rice with beans and vegetable salad combines cereals, pulses, and vegetables perfectly.
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Crops are classified by how long they live and produce. Annual crops complete their entire life cycle—from germination to seed production—in just one year. Maize is a perfect Nigerian example; you plant it, it grows, flowers, produces grain, and dies within twelve months. Biennial crops take two years to complete their cycle, growing leaves in year one and flowering in year two. Perennial crops live for many years and keep producing, like cassava and plantain which you can harvest multiple times. Ephemeral crops are rare and complete their life cycle in less than a year, usually in a few weeks.
Understanding these classifications helps farmers plan planting schedules and predict harvest times effectively.
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Crops are classified into two main groups based on their seed structure and leaf patterns. Monocotyledonous crops, or monocots, have seeds with only one cotyledon, which is a seed leaf. These plants typically have parallel leaf veins and fibrous root systems. Maize is a perfect Nigerian example of a monocot—notice how its leaves have lines running parallel to each other.
Dicotyledonous crops, or dicots, have seeds containing two cotyledons. Their leaves show a network pattern of veins, and they develop tap root systems. Beans, another common Nigerian crop, represent dicots perfectly. You can see how bean leaves display that branching vein pattern.
Understanding these differences helps you identify and classify crops correctly. The seed structure is the most reliable feature to use when determining which group a crop belongs to.
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