Arachnid

Question 1

What is the general body plan of an Arachnid

Answer 1

Prosoma = Feeding, Sensory, and locomotion - six segments 1st = double segmented chelicerae (3 in scorpion), 2nd = Pedipals (6 segmented), legs on rest - Abdomen holds Digestive, Reproduction, gas exchange organs/Spinnerets

Question 2

Describe the CNS

Answer 2

Highly developed, recalls infomation.

Brain -> Ventral nerve cord with Ganglia in each segment – Peripheral nerves in Prosoma/Abdomen

Question 3

Define a Ganglia

Answer 3

A cluster of nerves

Question 4

Describe the circulatory system

Answer 4

Open system - Heart + blood vessels - Haemocyanin Respiratory pigment

Question 5

Describe the Reproduction style

Answer 5

Dioecious via sperm package transfer via palp

Question 6

describe the Respiration system

Answer 6

Book lung/Tracheae or both.

Tracheaepasses O2 to Haemolymph via vessels (More efficient then book lungs

Question 7

Describe the gut

Answer 7

Complete gut - Fore gut -> Midgut -> Hindgut

Extra oral digestion via Midgut fluids + absorption site and Diverticulae

Question 8

Define Diverticulae

Answer 8

Increased surface area

Question 9

Describe the Excretory mechanisms

Answer 9

Coxal glands - Nephrocytes in Prosoma - Malpighian tubules