1. How does the sponge attach to the substrate if it is sessile? How does a sponge attach to a substrate if it doesn’t swim?

2. INSTRUCTIONAL OBJECTIVES 1. Describe the life cycle of a sponge 2. Identify the stages in a sponges development. 3. Explain how an adult sponge encrusts on a substrate

3. How does the sponge attach to a substrate if it can’t swim? SPONGE LIFE CYCLE. The adult SPONGE has no locomotion(sessile), but during its early development it was a swimming embryo and a temporary zooplankton. The period of time between early development and maturity is called the LIFE CYCLE. GUESS THE AIM???

4. AIM: How can we describe the life cycle of a sponge? Reproduction, The life cycle of a sponge begins with Reproduction, the activity by which organisms produce offspring. Sponges may have separate sexes or hermaphrodites(can change sex or has both male and female organs). KEY QUESTION: How does a multicellular sponge develop from a single cell? Show models

5. DRAW and LABEL: LIFE CYCLE OF A SPONGE ZYGOTE- ZYGOTE-a fertilized egg cell CLEAVAGE- CLEAVAGE-rapid division of a zygote EMBRYO- EMBRYO-organism at different cellular stages in development MORULA- MORULA-solid ball of cells BLASTULA- BLASTULA-hollow ball stage KEY QUESTION How and when does the embryo become a free KEY QUESTION How and when does the embryo become a free swimmer? swimmer?

6. How and when does the embryo become a free swimmer? Larva. When the cells of the blastula develop whip like flagella it enables the embryo to swim. The swimming embryo is called a Larva. When the larva attaches to a substrate it develops into an adult. The mature adult sponges release their gametes into the water fertilization and development are both external. Sponges can regenerate or bud asexually

7. SPONGE LIFE CYCLE SUMMARY The sponge develops from a single fertilized egg cell through various embryonic stages into a swimming larva before it matures into an adult. The sponge is sexual and asexual.

8. SPONGE LIFE CYCLE EXIT QUIZ 1. T or F. Correct for full credit Sponges are sessile their entire life cycle. 2. Which type of symmetry does an adult sponge exhibit? A. bilateral B. radial C. asymmetrical D. none of the above 3. Describe the difference between the zygote, morula and blastula stages in a chart. Describe the types of sponge reproduction.