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STUDENT OBJECTIVE

Students learn the processes of gamete formation in flowering plants and study plant development. Sexual and asexual reproduction are compared and flower diversity is illustrated. Anatomy of seeds and fruits are examined.

EQUIPMENT	AMOUNT
	(Class of 24 with 8 groups)
Compound microscope Dissecting microscope	1/student 1/student
MATERIALS
Razor blades Dissecting needles Microscope slides and coverslips Lens paper Living plants Lima beans, soaked Corn kernels, soaked Vinca flowers Various monopistillate flowers for dissection Six dicot flowers varying in completeness, some imperfect Apples, tomatoes, peaches, cucumbers, and other fruits Grasses with root Garlic plant with root Strawberry plants with stolons Iris plant with root Germinating dicot and monocot seeds Tulip or other large monocot Seeds (beans, spinach, turnip, etc.) Tobacco Hormone Kit (CBS) Wisconsin Fast Plants Kit (CBS) Wild type seeds Rosette seeds Growth Kit w/lighting Preserved plants Oat flowers (CBS#PB1210)* Examples of corn staminate and pistillate flowers (CBS#PB960)* Preserved lily flower bud (CBS#PB 1236)* Prepared slides (can be shared to reduce costs) Capsella (Shepherd’s purse) embryo, longitudinal section (CBS#30 4888)* Lily anther, cross section (CBS#30-4532)* Lily ovule, cross section Lily pollen tubes, longitudinal section (CBS#30-4616)*	1/student 2/student 1 box/lab 8/lab 1/student 1/student 1/student 1/student 2 sets/lab Demonstration Demonstration Demonstration Demonstration Demonstration 1/student 1/lab Demonstration 1/lab 1/lab 1/student Demonstration 1/student 1/student 1/student 1/student 1/student

*Please refer to the Appendix for name and address of supplier.

SOLUTIONS

PREPARATION

6 Weeks before Lab

Order tobacco hormone kit with callus to arrive 6 weeks before lab

About Three Weeks before Lab

Locate a local source of fresh flowers for lab (greenhouses or florists). Order flowers to arrive in midbloom to full bloom.

Order Wisconsin Fast Plants Kit to arrive 1 week before lab

Week before Lab

1. About three days before lab, soak lima beans and corn kernels so that students can dissect.
2. Plant seeds in tray of soil. Cover with vermiculite and keep moist. Vary time of planting so that seedlings at various stages of development are available for lab.
3. 10% sucrose preparation:
   10 g sucrose/90 ml water
   Store in dropper bottles.
   
   
4. Begin Wisconsin Fast Plants so that seedlings are 8 days* old when given to students.

Classroom activities

1. Check out the links for this lab topic at http://auth.mhhe.com/biosci/genbio/dolphin/ You will find useful materials for developing your lab introduction or summary, and in some cases, you may want to tell students to connect to a particular site for further information.

ANSWERS TO CRITICAL THINKING QUESTIONS

1. Tomato, cucumber, squash, peas, beans, egg plant, and peppers. All of these vegetables have flesh that is derived from the ovarian wall and they contain seeds.
2. Pollen from different species of flowers is often shed at different times of the year. If pollen arrives before the stigma is receptive it will not fertilize the eggs of a species. Sugary secretion and other chemical stimulants produced by one species may not trigger pollen tube formation in a second species. If the pollen tube forms and starts migrating through the tissues of the stigma and style, chemical signals of one species may not guide the pollen tube of a second species in appropriate manner so that the tube does not find the micropyle. In some species the pollen tube that forms may not be long enough or too long to find its way to the micropyle.
3. In alternation of generations, sex is expressed by the gametophyte stage of the life cycle. The female gametophyte is the embryo sac. The male gam^*etophyte is the pollen grain.

SUPPLEMENTAL MATERIALS