Porifera

Question 1

Porifera

Answer 1

scientific name for sponges
pore-bearing bodies that lack true tissues

Question 2

Choanocytes

Answer 2

flagellated cell that beats for water flow
- has mucus that traps marine snow
- carries out phagocytosis of food particles
- develops into sperm

Question 3

Amoebocytes

Answer 3

cells next to choanocytes that digests absorbed food
- undergoes meiosis to a haploid ovule

Question 4

Where are porifera found?

Answer 4

deep ocean, dont need light and so less competition
stick out into the current to catch marine snow

Question 5

multicellularity vs. colonial

Answer 5

working in cooperation, dependent on all cell types for function

Question 6

advantages of multicellularity

Answer 6

specialisation of cells
range of function
larger growth, more protection or mobility
cell collaboration

Question 7

disadvantages of multicellularity

Answer 7

reduced SA:V ratio

Question 8

SA:V ratio

Answer 8

Surface area to volume ratio
- limits direct exchange with the environment
as biomass gets bigger, so more demand, there may not be enough surface area and too big a distance into the cell, so better to have lots of smaller cells in contact with the environment

Question 9

Heterotrophic feeding process

Answer 9

1. ingestion/intake of food
2. digestion/breakdown of food
3. absorption/uptake of nutrients
4. elimination/removal of waste

Question 10

Reproductive development in porifera

Answer 10

choanocyte = sperm
amoebocyte = egg
- spawning event when sperm are released to the water column and filter through another sponge to be absorbed
only develops to a blastula state