Note
Studied by 9 people
Bio Oral Exam
1. Phylum Classification
Animal | Phylum | Key Traits |
Crayfish | Arthropoda | Exoskeleton, jointed legs, segmented body |
Sponge | Porifera | Asymmetrical, pores, filter feeders |
Sea Star | Echinodermata | Radial symmetry, tube feet, spiny skin |
Clam | Mollusca | Soft body, shell, muscular foot |
📌 2. Body Symmetry
Animal | Symmetry Type |
Crayfish | Bilateral |
Sponge | Asymmetrical |
Sea Star | Radial (pentaradial in adults) |
Clam | Bilateral |
📌 3. Clam Dissection – Parts & Functions
Gills – Respiration and feeding
Mantle – Secretes the shell
Foot – Movement and burrowing
Adductor Muscles – Open/close shell
Shell – Protection
Helpful Image:
(Source: Wikimedia Commons)
📌 4. Crayfish Dissection – Parts & Functions
Chelipeds (claws) – Defense and food capture
Swimmerets – Reproduction and swimming (help ID sex)
Antennae – Sensory function
Heart – Circulates hemolymph (open circulatory system)
Gills – Gas exchange
Helpful Image:
(Source: Wikimedia Commons)
📌 5. Male vs. Female Crayfish (Sex Differences)
Feature | Male | Female |
Swimmerets | First pair enlarged & stiff (used to transfer sperm) | All swimmerets soft/similar |
Genital Openings | At base of 5th walking legs | At base of 3rd walking legs |
Helpful Image:
(Source: biologycorner.com)
A sagittal plane divides a body into left and right portions.
A frontal plane (also called coronal) divides a body into front (anterior) and back (posterior) portions.
A transverse plane divides a body into top (superior) and bottom (inferior) portions.