Test 3 Study guide

Question 1

What is ecdysis?

Answer 1

The process of shedding or molting the outer cuticle in arthropods, insects, and some reptiles, allowing for growth

Regulated by the hormone ecdysone

Question 2

What is the branchial basket?

Answer 2

A cartilaginous structure supporting the gills in protochordates and lower vertebrates, such as ascidians, amphioxi, and cyclostomes

Question 3

Define notochord.

Answer 3

A flexible rod-like structure of mesodermal cells that serves as the principal longitudinal structural element in chordates and the early embryo of vertebrates

Question 4

What are tagmata?

Answer 4

Functional body regions in arthropods formed by the fusion of multiple segments, typically including the head, thorax, and abdomen

Question 5

What is the function of the endostyle?

Answer 5

A pair of parallel longitudinal folds projecting into the pharyngeal cavity in lower chordates that secrete mucus for trapping food particles

Question 6

What are pharyngeal gill slits?

Answer 6

Openings in the pharynx that allow water to exit after passing over the gills, present in various stages of development in chordates

Question 7

What is a cephalothorax?

Answer 7

A combined head and thorax region found in some arthropods, such as arachnids and crustaceans

Question 8

Define tube feet.

Answer 8

Small, flexible, hollow appendages found in echinoderms used for movement, feeding, and attachment

Question 9

What does echinoid pertain to?

Answer 9

Sea urchins, a class of echinoderms characterized by their spherical shape and spiny exoskeleton

Question 10

What is a mandible?

Answer 10

The lower jawbone in vertebrates, essential for mastication and speech, supporting the lower teeth and protecting facial structures

Question 11

What is a gastrovascular cavity?

Answer 11

A central cavity in certain invertebrates that serves both digestive and circulatory functions

Question 12

What is an asteroid?

Answer 12

A class of echinoderms, commonly known as sea stars, characterized by their star-shaped body and radial symmetry

Question 13

Define pentaradial symmetry.

Answer 13

A body plan symmetry where body parts are arranged around a central axis in five parts, typical of echinoderms like sea stars

Question 14

What is a brachiolaria larva?

Answer 14

A larval stage in certain echinoderms characterized by the presence of arms and a stalk

Question 15

What is an incurrent siphon?

Answer 15

An opening in certain marine organisms through which water enters the body for feeding and respiration

Question 16

What is an excurrent siphon?

Answer 16

An opening in certain marine organisms through which water exits the body after passing over the gills

Question 17

Define malacostraca.

Answer 17

A large class of crustaceans including crabs, lobsters, and shrimp, characterized by a segmented body and jointed limbs

Question 18

What is Crustacea?

Answer 18

A diverse subphylum of arthropods, encompassing species like crabs, lobsters, and shrimp, typically having a hard exoskeleton and jointed limbs

Question 19

What does Uniramia refer to?

Answer 19

A former classification group for arthropods with unbranched appendages, including insects, millipedes, and centipedes

Question 20

What is meristomata?

Answer 20

An outdated term that may refer to the class Merostomata, which includes horseshoe crabs and extinct relatives

Question 21

Define cirri.

Answer 21

Feathery appendages found in certain marine organisms, like barnacles, used for feeding and respiration

Question 22

What is an ampulla?

Answer 22

A bulbous sac-like structure in echinoderms, part of the water vascular system, aiding in movement and feeding

Question 23

What does Crinoidea refer to?

Answer 23

A class of echinoderms, known as feather stars or sea lilies, characterized by their feathery arms and sessile or free-moving lifestyle

Question 24

What is a pluteus larva?

Answer 24

A free-swimming larval stage in echinoderms characterized by a bilaterally symmetrical body and ciliated arms

Question 25

What is the epicuticle?

Answer 25

The outermost layer of the exoskeleton in arthropods, providing waterproofing and protection

Question 26

Define endocuticle.

Answer 26

The inner layer of the exoskeleton in arthropods, located beneath the epicuticle, providing structural support

Question 27

What is an ocellus?

Answer 27

A simple eye found in some invertebrates, capable of detecting light intensity but not forming detailed images

Question 28

What are chelicerae?

Answer 28

Paired appendages near the mouth in arachnids, often modified for feeding or defense

Question 29

What are maxillae?

Answer 29

Paired appendages in arthropods, located behind the mandibles, used for manipulating food and assisting in feeding

Question 30

What is the abdomen of an arthropod?

Answer 30

The posterior segment of an arthropod's body, housing digestive, reproductive, and excretory organs

Question 31

What are antennae?

Answer 31

Paired sensory appendages on the head of arthropods, used for detecting environmental stimuli

Question 32

The cypris larva is a non-feeding larval stage of _______.

Answer 32

barnacles

Question 33

Define pharynx.

Answer 33

A muscular tube in the throat region of animals that connects the mouth to the esophagus, involved in swallowing and respiration

Question 34

What is Holothuroidea?

Answer 34

A class within phylum Echinodermata, commonly known as sea cucumbers, with a soft, elongated body and tube feet for movement and feeding

Question 35

What does Thaliacea refer to?

Answer 35

A class of free-floating tunicates, including salps, important in carbon cycling due to their rapid reproduction and sinking fecal pellets

Question 36

What is Cephalochordata?

Answer 36

A subphylum of chordates that includes lancelets, small fish-like marine animals that retain all major chordate features throughout life