Lesson 23b

Question 1

What is in subphylum Chelicerates?

Answer 1

Spiders, Horseshoe Crabs, Ticks, Scorpions

Question 2

What are 2 characteristics of chelicerates (a subphylum)?

kuh-li-seh-rates

https://forvo.com/word/chelicerate/

Answer 2

a. 2 body sections

b. Claw-like appendages

Question 3

What two classes fall under subphylum Chelicerates?

Answer 3

a) Class Merostomata: horseshoe crabs

b) Class Arachnid: spiders, ticks, mites, and scorpions

Question 4

Give a simple explanation of spiders silk (from class Arachnid)…

Answer 4

a) Spinnerets are structures located at the tip of the abdomen, used to spin silk
b) Each spinneret structure contains hundreds of tiny tubes allowing liquid silk to flow from silk glands
c) The liquid silk hardens as it flows through the spinnerets and is exposed to air
file: ///C:/Users/trgan/Sync/LisA%20school/Aracnids%20silk.png

Question 5

What are 5 characteristics of arachnids?

Answer 5

a) Terrestrial (living on land)
b) 8 legged
c) Pair of pedipalps used for sensing or feeding
d) Two segments: cephalothorax (fused head and thorax) and abdomen
e) No wings or antennae

Question 6

Explain the structure Arachnids…

• exoskeleton?
• eyeballs
• mouth/how kill and eat prey x4
• what used to make web
• legs

Answer 6

a) Protective exoskeleton
b) Six or eight simple eyes, but no compound eyes

c) Short pair of appendages called chelicerae used to capture and crush prey
d) Fangs located at the end of the chelicerae, used to inject venom
e) Mouthparts located under chelicerae, but not often used for chewing
f) Pedipalps located between chelicerae and the first pair of legs which may contain pincers
(1) Can be used to capture prey
(2) Used in spiders for shaping their web
(3) Often used for transferring sperm from male to female

g) Four pairs of jointed legs on the cephalothorax

Question 7

Give a simple explanation of an Arachnids respiratory system…

Answer 7

a) Openings called spiracles are on the abdomen where air enters and branches into tiny tubules

b) Air then either enters trachea or book lungs
(1) Trachea delivers gasses throughout the body
(2) Book lungs are respiratory organs with many thin layers where air circulates and the exchange of gasses takes place—oxygen passes into a blood filled chamber

file:///C:/Users/trgan/Sync/LisA%20school/Aracnids%20breathing.png

Question 8

Explain how Arachnids reproduce…

Answer 8

a) Gonads and genital opening are located on the underside of the abdomen

b) Male delivers sperm to the female in a package called a spermatophore and it’s stored for fertilization
(1) Eggs become fertilized as they’re laid by the female
(2) Eggs hatch into young that look similar to adults

c) Scorpions do not lay eggs, but instead lay live young

Question 9

What is in Subphylum Myriapoda?

What two classes are in it?

Answer 9

Centipedes and Millipedes

A. Class Chilopoda: centipedes

Chill-a-poh-duh

https://www.google.com/search?q=chilopoda+pronunciation

B. Class Diplopoda: millipedes

die-plow-pod-uh

https://www.google.com/search?q=diplopoda+pronunciation

Question 10

Briefly explain class Chilopoda…

Answer 10

The Centipedes

1. 30 to 354 legs
2. Carnivores with venomous claws on the first set of legs used to paralyze prey
3. Flattened bodies divided into segments; each segment has one pair of walking legs
4. On the head, there’s a pair of antennae, three pairs of appendages modified as mouthparts, including the jawlike mandibles

Question 11

Briefly explain class Diplopoda…

Answer 11

The millipedes

1. 24 to 750 legs
2. Round bodies divided into segments; each segment has two pairs of walking legs
3. Saprophytes: eat decaying leaves and plant matter

Question 12

What is subphylum Crustaceans known as?

What is in subphylum Crustaceans?

How many body segments?

Answer 12

The aquatic Arthropods

Barnacles, Crabs, Lobsters, Crayfish, Shrimp, Woodlice, and Beachfleas

Two body segments: cephalothorax and abdomen

Question 13

Explain the structure/things on the cephalothorax of organisms in subphylum Crustaceans…

Answer 13

A. 2 compound eyes
B. 2 pairs of antennae

C. 3 pairs of mouthpiece parts

    (1) Mandibles used to hold and crush food
    (2) Two pairs of maxillae used for feeding

E. Cephalothorax is covered by a single exoskeletal plate called a carapace

F. Appendages

    (1) Five pairs of legs
            a) Chelipeds: claws on the first pair of legs used for grooming, fighting, and capturing prey
            b) Other legs are used for walking

Question 14

Explain the structure/things on the abdomen of organisms in subphylum Crustaceans…

Answer 14

1. Swimmerets: appendages used for swimming and reproduction

2. Telson: fan shaped tail at the end of the body

Question 15

Explain Crustaceans respiratory system…

Answer 15

Gills are used to extract oxygen from the water, but smaller crustaceans breathe via diffusion through their skin

Question 16

V briefly explain Crustaceans…

  - digestive system
  - circulatory system, if they have one
  - nervous system, if they have one

Answer 16

1. Complete digestive system
2. Open circulatory system
3. Nervous system with 2 ganglia and a nerve cord

Question 17

How do Crustaceans reproduce?

Answer 17

Sexually, usually external

Sperm is deposited and eggs are laid on them and they are fertilized

Eggs wait to hatch in swimmerets

Question 18

Lesson 23b subphylums: Chelicerates, Myriapoda, Crustaceans summary

Answer 18

file:///C:/Users/trgan/Sync/LisA%20school/Lesson%2023%20Phylum%20Arthropoda,%203%20subphylums%20summary.mp4