Exam 4 Ch 19

Question 1

What four evolutionary trends were discussed with Aves in lecture?

Answer 1

1. reduction of body size
2. reduction (fused) digits
3. preumatic bone (not completely hollow, but not solid)
4. feathers.

Question 2

What is the difference between symmetrical and asymmetrical feathers?

Answer 2

Symmetrical feathers are for warmth, whereas asymmetrical feathers are for flight.

Question 3

in what year was Archaeopteryx lithographica discovered?

Answer 3

1861

Question 4

List the theropod characteristics discussed in lecture.

Answer 4

1. ???
2. legs under body
3. bipedal (walk on two legs)
4. long tail
5. lightweight bones
6. nest makers
7. teeth
8. claws on front limbs

Question 5

What three characteristics do birds have that theropods dont?

Answer 5

asymmetrical feathers
keel-like sternum
furcula (wishbone)

Question 6

What are the two groups of modern birds?

Answer 6

Paleognaths and Neognaths

Question 7

True or false. Paleognaths are flightless birds.

Answer 7

True.

Question 8

What two characteristics were discussed in lecture inn regard to Paleognaths?

Answer 8

a flat sternum

poorly developed pectoral muscles

Question 9

True or False. Neognaths are the largest group of birds and do not include penguins.

Answer 9

False.

Question 10

What two characteristics distinguish Neognaths from Plaeognaths?

Answer 10

a keeled sternum

well-developed pectoral muscles

Question 11

True or False. Aves are the second largest group following fish in vertebrates.

Answer 11

True.

Question 12

How many Avian species have been identified?

Answer 12

10,400+

Question 13

True or false. Aves live in all biomes.

Answer 13

True.

Question 14

What hallmarks of avian diversity were mentioned in lecture?

Answer 14

feathers/flight
hind limbs adapted for walking, swimming, perching
lay eggs
Wings: present for lift and propulsion
Bones: provides light rigid airframe

Question 15

What parts of feather anatomy were discussed in lecture?

Answer 15

Quill, vane, barb, barbules, and shaft

Question 16

True or False. Feather growth and development is different than scales in reptiles.

Answer 16

False. They are the same.

Question 17

Explain feather growth and development.

Answer 17

formation of out growth, follicle, then epidermal ridges (which give rise to barbs and barbules.)
Then the surrounding sheath degenerates

Question 18

True or False. Feathers molt multiple times a year.

Answer 18

False. They generally molt once a year after nesting.

Question 19

What three molting patterns were discussed in lecture?

Answer 19

1. Most: pairs of flight and tail feathers lost to maintain balance.
2. continuous replacement
3. primary feathers are lost all at once. (water birds can’t fly, so easy predation.)

Question 20

What are pneumatized bones?

Answer 20

strong but light weight bones

Question 21

What four characteristics of Avian skulls were discussed in lecture?

Answer 21

1. large braincase and orbits
2. one occipital condyle at the base of the skull which allows for more rotation for the skull.
3. Diapsid but not easily determined and modified
4. Keratinized beak molded around bony jaws

Question 22

True or False. All avian vertebrae are fused except cervical vertebrae (neck bones).

Answer 22

True.

Question 23

What is the pygostyle?

Answer 23

equivalent to the coccyx in humans. It is the tail vertebrae, fused and shortened.

Question 24

What is the synsacrum?

Answer 24

a light and thin sacrum. has fused sacral vertebrae and pelvic girdle.

Question 25

What is the uncinate process?

Answer 25

extra section of ribs braced against each other to brace for landing. (look up again.)

Question 26

True or False. Aves have a fused clavical form of furcula or wishbone.

Answer 26

True.

Question 27

True or false. The sternum in birds has a large keel. This helps attach powerful muscles to the skeleton.

Answer 27

True.

Question 28

Forelimbs are modified for flight and...

Answer 28

some bones are reduced in number or fused.

Question 29

What two muscles are adapted for flight in birds?

Answer 29

the pectoralis and the supracoracoideus.

Question 30

What is the pectoralis muscle in birds?

Answer 30

the largest, outermost muscle that depresses (pulls down) wing during flight. It attached underneath the humerus.

Question 31

What is the supracoracoideus muscle in birds?

Answer 31

it raises wings, lays under the pectorals, and snakes above to attached to the top side of the humerus.

Question 32

True or False. Both the pectoralis and supracoracoideus muscles attach to the keel.

Answer 32

True.

Question 33

What are the advantages to the main leg muscle mass in the thigh of Aves?

Answer 33

connects to the feet and toes by long tendons. Allows for a locking mechanism with perching tendons, which enable a bird to sleep in a perching position and not fall off.

Question 34

What adaptations for flight were discussed in regards to food, feeding and digestion?

Answer 34

1. rapid digestion 2. long, muscular esophagus 3. the crop allows them to eat a lot and process as it goes 4. stomach 5. paired ceca that form fermentation chambers 6. cloaca 7. varied food habits

Question 35

What are the two parts of the stomach in Aves called?

Answer 35

the proventriculus which secretes gastric juices and the gizzard for grinding food.

Question 36

What is the difference between stenophagous and euryphagous?

Answer 36

stenophagous means they have a specific diet, euryphagous means they can eat a varied diet.

Question 37

What three adaptations for flight were produced in the Aves circulatory system?

Answer 37

a four chambered heart their heartbeat is inversely proportional to size blood cells have nucleated biconvex RBCs and phagocytes for repairing wounds and destroying microbes.

Question 38

How is the Avian respiratory system adapted for flight?

Answer 38

they have the most efficient system of terrestrial vertebrates 9 air sacs that extend into the thorax and abdomen. takes 2 respiratory cycles for a single breath to pass through a system

Question 39

How is the Avian excretory system adapted for flight?

Answer 39

1. two large metanephric kidneys (like us) w thousands of nephrons. (look like large nephridia clumped together.) 2. concentration of uric acid in the cloaca (absorbs water) 3. Marine birds (due to large salt loads) have salt glands that remove excess salt from the seawater they drink.

Question 40

How is the Avian nervous system adapted for flight?

Answer 40

1. they have well developed cerebral hemispheres (problem solving) and a well developed cerebellum (balance and coordination) as well as a well developed optic lobe (big eyes.) 2. poorly developed sense of smell (except in flightless, oceanic, and waterfowl) 3. good hearing but no pinna. have a hole in skull like reptiles. 4. Excellent vision

Question 41

How is Avian vision adapted for flight?

Answer 41

1. eyes are large relative to body size 2. less spherical and almost immobile 3. The retina has rods and cones, a pecten, or highly vascularized organ that connects to the retina and serves to bring more oxygen to cue. 4. 2 foveae for sharp monocular and binocular vision.

Question 42

Explain the male reproductive system in Aves.

Answer 42

1. 2 testes that remain small until mating season, then grow large to mate. 2. no portusible (protruding) copulatory organ (penis) 3. pushes cloaca together.

Question 43

Explain the female reproductive system of Aves.

Answer 43

1. only the left ovary and oviduct develops fully. | 2. right side degenerates but can develop if the left side is injured or non-functionable.

Question 44

Explain egg formation in Aves.

Answer 44

1. fertilization occurs in upper oviduct (sperm can live there for several days) 2. lay one egg a day 3. glands add albumin as egg passes down oviduct 4. The shell, membrane and pigments added in uterus.