lab 12 Flashcards
1
Q
Homologous structure
A
- characteristic shared by 2+ species that’s similar bc of common ancestry
- may or may not have same func.
- e.g. human, whale, bat, cat all have similar forearm
2
Q
Analogous structures
A
- similar structures that serve same function, but not from CA
- convergent evolution
- e.g. flight/wings
3
Q
Phylogeny for birds and mammals
A
Amniotic Egg = teptiles, birds, mammals
Diapsid skull = reptiles and birds (mammals have synapsid skull)
Adaptions for flight = birds
4
Q
Pigeon classification
A
-Vertebrate specially adapted for flight Kingdom: animalia Phylum: chordata Class: Aves Fam.: Columbiformes Genus: Columba Species: C. livia Subspecies: C. l. domestica
5
Q
Pigeon Skeleton
A
- large sternum/keel for flight muscles to attach to
- fused pectoral girdle/clavicle = wishbone –> also for flight muscle attachment
- Wings = 1 big, 2 small, lots of little bones –> little bones are all fused for flapping (won’t bend during downstrokes)
- flexible bones prevent them from breaking during pressures in flight
- no teeth
6
Q
Pigeon mass
A
- very light
- hollow bones
- pneumatic bones = major bone hollows with struts (air spaces connected to respiratory system)
7
Q
2 Major flight muscles
A
Pectoralis
- big, superficial
- origin: keel/sternum
- inserts @ underside of humerus
- depress wing (downstroke)
Supracoracoideus
- small, deep
- origin=sternum; insertion=topside(dorsal) of humerus
- goes over clavicle
- elevates the wing (upstroke)
8
Q
Respiratory system
A
- lung and air sacs allow flight to occur
- constant supply of air to lung and cuts down on weight
- no diaphragm
- lungs surrounded by 8-9 air sacs (not for gas exchange)
9
Q
Air flow
A
Inhale 1: abdominal air sac
Exhale 1: lungs for gas exchange
Inhale 2: forward (anterior) air sac
Exhale 2: CO2 is expelled
10
Q
Feathers
A
- Primary and seondary wing feathers = main flight feathers –> lost and regrown annually
- priamary feathers attach to digits
- some species only have color on their secondary coverts
11
Q
bird digestion
A
crop
- giant sac to hold food
- can stretch a lot
gizzard
- where food goes next to be crushed up in prep for digestion
- lots of muscles and tendons
- some birds eat small rocks to help with crushing seeds
12
Q
Reproductive organs
A
-Don’t need to reproduce during winter and fall, so they shrink reproductive organs to cut weight