Amniota Flashcards
1
Q
Amniota
A
Non-avian reptiles + Birds + Mammals
2
Q
Reproduction in amniotes
Amniota
A
- Amniotic membrane around embryo
- Internal fertilization
- Lay eggs on land or retained within mother
3
Q
Adaptations of amniotes
A
- Amniotic egg
- Thicker & more waterproof skin
- Rib ventilation of the lungs
- Stronger jaws
- High-pressure cardiovascular system
- Water-conserving nitrogen excretion
- Expanded brain & sensory organs
4
Q
Amniotic egg
What are the 4 extraembryonic membranes
A
- Amnion
- Chorion
- Allantois
- Yolk sac
5
Q
Embryonic membranes
Amnion
A
- Encloses embryo in fluid
- Cushions embryo
6
Q
Embryonic membranes
Chorion
A
- Surrounds the entire egg
- Highligh vascularized
- Participates in gas exchange
- Development of placenta in most mammals
7
Q
Embryonic membranes
Allantois
A
- Participates in gas exchange
- Stores metabolic waste in birds and non-avian reptiles
- Development of placenta in most mammals
8
Q
Embryonic membranes
Yolk sac
Also found in anamniotes
A
- Stores nutrients
- Contributes to the placenta in mammals and marsupials
9
Q
Waterproof skin
A
- Skin protected by hairs, scales, feathers
- Thicker, tougher, more waterproof
- Few use skin for respiration
10
Q
Rib ventilation of the lungs
A
Negative ventilation breathing (expand thoracic cavity to pull air into lungs)
11
Q
Stronger jaws
A
- Mammals have strong jaws adapted for mastication
- Amphibians and some reptiles have teeth but dont chew
- Fish jaw is designed for suction feeding
12
Q
High-pressure cardiovascular system
A
- Higher metabolic need
- Heart must pump blood ‘uphill’ against gravity
- Heart is segmented (fish = 2 chambers; amphibians/non-avian reptiles = 3 chambers; birds/mammals = 4 chambers)
13
Q
Water-conserving nitrogen excretion
A
- Ammonia
- Urea
- Uric acid
14
Q
Ammonia
A
- Most aquatic organisms
- Toxic at relatively low concentrations
- Must be diluted with large amounts of water
15
Q
Urea
A
- Mammals and amphians
- Less toxic, less dilution required
- Concentrated in kidneys
