Lab 1

Question 1

What do all CHordates have?

Answer 1

1.notochord
2.perforated pharynx
3.dorsal nerve cord
4.post-anal tail
5. endosytyle or thyroid gland

Question 2

Pharynx
-have what?
-is important for?

Answer 2

slits or holes to allow water that has entered through the mouth to exit without going to the digestive tract

-gas exchange, jaw support, hearing

Question 3

Notochord
-has a ____which flexes laterally
-is composed of large___
-in most vetebrate is present___
-in adults only____

Answer 3

elastic rod
fluid-filled cells encased in stiff fibrous tissue
present in embryos only
remnants present like the diskc between vertebrae

Question 4

Nerve cord
-tube dorsal to ___
-develops from___
-develops into___

Answer 4

notochord
-ectoderm
the brain and spinal cord

Question 5

Postanal tail
-contains___
-provides___

Answer 5

contains skeletal and muscle elements
-propulsive force

Question 6

Endostyle or thyroid gland
____metabolism
-elongated, ciliated groove in___ that produces___

Answer 6

iodine metabolism
pharynx floor produces mucus that traps food particles

Question 7

Cephalochordates

larvae:
adults:
gas exhange:
Pharyngeal slits:

Wheel organ

Answer 7

also called lancelets or amphioxus

larvae:planktonic and feeding
gas: mainly across external body surfaces
adults: can swim but burrow
slits:involved in filter feeding

beating og cilia on the wheel organ(ridges ontop of mouth) draw water into the pharynx.

Question 8

Tunicates
-sessile suspension feeders
-possess a ___larval stage

-what chordate charactisic found on in tadpole larva
-tubular heart ___
-pharyngeal slits:
water movement

Answer 8

-distinct
-a tail with notochord and dorsal nerve cord and tail found only in larval stage
-reverses direction of pumping
-have a endosyle
-involved in filter feeding, muscus traps food particles and cilia moves them to esophagus
-incurrent siphon, pharyngeal slits, atruim, excurrent siphon

Question 9

Vetebrates(subphylum——)
-What single characterisitc is different in vertebrates then protochordates?
-highly develped anterior brain(______)
___tissue that forms during embroy develpment and migrates throughout the body to give shape to a body
-somites?
-Kidneys

Answer 9

(Vertebrata)
-the replacement of the unsegmented notochord to a bony vertebral column
cephalization
-neural crest
-Have mesodermal somits that is present in emboys and give rise to skeletal muscles ect.
-Paired kidneys that excrete noritgenous waste

Question 10

How to do a scale bar?

Answer 10

drawing sizex (0.1mm)/actual size