Question

puzzle #7 - sponge reproduction

1. which is not an option for how sponges reproduce?

a. cells on the side or base of the sponge begin to bulge out and form a new sponge
b. two touching sponges can transfer sperm and eggs with each other via their holdfasts
c. internal buds form inside the sponge, becoming adult sponges when water conditions are favorable
d. a sponge releases sperm in the water which enter another sponge, fertilizing the eggs on the inside

1. what is a gemmule?

a. a collection of a variety of types of sponge cells in a protective membrane that can survive harsh water conditions
b. a variety of spicule that has 6 points and can attach to other spicules like velcro
c. a formal name for a sperm cell or an egg cell
d. an external bud that forms on the side of a sponge and breaks off to form a new organism

1. true or false: sponge buds can stay attached their parent sponge to form a colony.

a. true
b. false

1. what is a hermaphrodite?

a. an organism that produces neither eggs nor sperm
b. an organism that is capable of both asexual and sexual reproduction
c. an organism that can fertilize its own eggs
d. an organism that can produce both eggs and sperm

1. which is a true sequence of events in sponge sexual reproduction?

a. a sponge releases sperm cells through its ostia, which enter the osculum of another sponge
b. a sponge releases egg cells through its ostia, which enter the osculum of another sponge
c. a sponge releases sperm cells through its osculum, which enter the ostia of another sponge
d. a sponge releases eggs through its osculum, which enter the ostia of another sponge

1. which is a true sequence of events in sponge sexual reproduction?

a. sperm cells are too large to fit through the ostia, so they become trapped. fertilization occurs in the ostia.
b. the egg cells are held in place by the choanocytes. the sperm cells can fertilize the egg cells inside the spongocoel.
c. choanocytes trap the sperm cells, transferring them to the mesohyl where they fertilize the egg cells.

1. which is a true sequence of events in sponge sexual reproduction?

a. the zygotes develop into buds, which can grow on the outside or inside of the sponge
b. the zygotes develop into swimming larva, are released from the adult sponge, and swim until they develop further and settle on a surface.
c. the zygotes develop into larva that look like small sponges, which are shot out of the sponge and float freely through the ocean until they settle on the ground.

Explanation:

1. Sponges do not transfer sperm and eggs via holdfasts. Holdfasts are for attachment, not reproduction.
2. Gemmules are collections of sponge - cells in a protective membrane for survival in harsh conditions.
3. Sponge buds can stay attached to form colonies.
4. A hermaphrodite is an organism that can produce both eggs and sperm.
5. Sponges release sperm through the osculum which enter the ostia of another sponge.
6. Choanocytes trap sperm cells and transfer them to the mesohyl for fertilization.
7. Zygotes develop into swimming larvae, are released, and swim until they settle.

Answer:

1. B. Two touching sponges can transfer sperm and eggs with each other via their holdfasts
2. A. A collection of a variety of types of sponge cells in a protective membrane that can survive harsh water conditions
3. A. True
4. D. An organism that can produce both eggs and sperm
5. C. A sponge releases sperm cells through its osculum, which enter the ostia of another sponge
6. C. Choanocytes trap the sperm cells, transferring them to the mesohyl where they fertilize the egg cells.
7. B. The zygotes develop into swimming larva, are released from the adult sponge, and swim until they develop further and settle on a surface.