Life Science Grade 11

Grade 11 Life Sciences Lesson PlansGRADE 11 SUBJECT LIFE SCIENCE WEEK 6 TOPIC SIGNIFICANCE OF SEEDS – SEED BANKS ANDAS A FOOD SOURCELesson 4LESSON SUMMARY FOR: DATE STARTED:DATE COMPLETED:CONTENT:• The structure and germination of seeds• Seeds as a food source• Seed banks and endemic species to South AfricaLESSON OBJECTIVESThe learners must be able to:• Describe the structure and germination process of seeds• Explain the significance of seeds as a food source• Describe what a seed bank is and its importance• Identify endemic species of plants that bear seeds in Africa• Complete questions on the significance of seedsTEACHER ACTIVITIES LEARNER ACTIVITIES TIMING RESOURCES NEEDED1. Introduction:• Remind learners that seed plants (Spermatophytes) are one of themost dominant group of plants on land• Ask learners what advantages they think seeds have given plants likeout food crops over plants such as mosses and ferns (the fact thatseeds can lie dormant for years allows them time to wait forfavourable conditions for growth)1. Learners discuss advantages to havingseeds as compared to spores5 min2. Main Body / Presentation• Use diagrams in the text book, wall charts or Internet references topoint out the following structures in seeds.• Have learners write down the following information in their workbooksExplain to learners the following :• A fertilized ovule becomes a seed.• All plants that are seed bearing belong to Phylum Spermatophyta.• A seed consists of three parts: a testa (seed coat) which protects theembryo, a cotyledon (seed leaves) which provides temporary food forthe developing embryo and the embryo (immature plant) which willdevelop into a new plant after germination• Since seeds contain very little water, they can survive for long periodswithout germinating• When climatic conditions are favourable for survival, the cotyledonsswell and split the testa and growth starts• Different seeds need different conditions for germination E.g. Proteaneed fire before they begin to germinate• Seed are a source of food and the reserves that are stored in seeds20min• Solutions for all LifeSciences Gr. 11 pp. 76 –83; Oxford Successful LifeSciences pp. 48 – 51Term 1 Page 52© Gauteng Department of Education (CAPS version)