Module 8

Module 8—Populations, Individuals, and Gene Pools

Lesson 11—r- and K-Selected Growth Patterns

Get Focused

Consider the dandelion: a lovely yellow flower with a bad reputation. Dandelions can be seen bursting through lawns in the spring to create colour and cheer. Unfortunately, Canadians consider dandelions a weed, and often uses herbicides in an attempt to get rid of them before they out-compete the grass species in lawns.

Many other cultures look forward to dandelion season to harvest the dents du lion (lion’s teeth) leaves as one of the first edible species of spring, providing vitamins and minerals after a long winter without fresh vegetation. The plants produce their flower rapidly, the petals fall away, and the fluffy seed heads are dispersed by wind to far-away places where competition won’t be a limiting factor. The entire life cycle is completed in three weeks.

This short life cycle ensures reproduction is completed before frost, drought, heat, or flooding is able to prevent it. Unstable abiotic factors like these require a life strategy that produces as many offspring as possible, as quickly as possible, and with little or no investment of energy into parenting or ensuring the survival of offspring by the plants. Is this typical of all organisms? Are there other strategies?

In this lesson the following focusing question will be examined:

• What are the characteristics and reproductive strategies of r- and K-selected organisms?

Module 8: Lesson 11 Assignment

Download a copy of the Module 8: Lesson 11 Assignment to your computer now. You will receive further instructions on how to complete this assignment later in the lesson.

In addition to your lesson work, any summary notes, sample problems, diagrams, charts, or tables should be stored in the course folder for your teacher’s feedback and your study as you prepare for exams.

You must decide what to do with the questions that are not marked by the teacher. Remember that these questions provide you with the practice and feedback that you need to successfully complete this course. You should record the answers to all of the questions and place those answers in your course folder.

Remember, you also have the option of trying additional questions from the textbook for further practice. Consult with your teacher for the answers to these questions. The Key will also provide you with many Diploma Exam style multiple choice, numerical response, and written response questions that will be an excellent review of the module. Practising your responses to these types of questions is good preparation for the Diploma Exam.