Lecture 7 (test 2 content) Flashcards
What are chordate features?
- Nerve cord
- Notochord
- Pharyngeal slits
- Postanal tail
What are chordates?
Animals belongs to the phylum Chordata
How Vertebrates connected to chordates?
Vertebrates are chordates with a spinal column
What is the vertebral column?
it encloses and protects the dorsal nerve cord
How is the head in vertebrates distinguished from nonvertebrates?
The head is distinct and well-differentiated processing sensory organs
When did the first vertebrates appear?
In the ocean about 530 MYA
What soon became dominant in the oceans about 530 MYA?
Jawed fishes
When did Birds and mammals become dominant?
after the Cretaceous mass extinction
What are the three major groups of Bony Fish?
- Ray0 finned fishes ( no muscles within the fins)
- Lungfish ( long fleshy muscular lobe)
- Coelacanths
What are the 5 distinguishing amphibian features?
- Legs
- Lungs
- Cutaneous respiration
- Pulmonary veins
- Partially divided heart
What did amphibians develop to adapt to life on land?
legs
What is essentially cutaneous respiration for amphibians?
supplement lungs
What are pulmonary veins used for with amphibians?
separate pulmonary circuit allows higher pressure blood to tissues
How is having a partially divided heart useful for amphibians?
it improves separation of pulmonary and systemic circuits
How many different species of reptiles are there?
over 10,000
What three features do all living reptiles exhibit?
- Amniotic eggs
- Dry skin
- Thoracic breathing
How are reptiles distinguished?
by the number of holes on side of the skull behind eye orbit
If a reptile has 0 holes on side of the skull behind orbit, what type of reptile is it?
anapsid
If a reptile has 1 holes on side of the skull behind orbit, what type of reptile is it?
synapsid
If a reptile has 2 holes on side of the skull behind orbit, what type of reptile is it?
diapsids
What type of reptile rose to dominance first?
synapsids
What type of reptile was the first land vertebrates to kill beasts their own size?
pelycosaurs
What are considered to be the be the “mammal-like” reptile?
Therapsids
When did Therapsids replace Pelycosaurs?
about 250 MYA
What is the most famous Diapdid?
Archosaurs
What are Archosaurs famous for?
They were the first land vertebrates to be bipedal
When were therapsids replaced by diapsids?
About 230 MYA
How long did Dinosaurs dominant?
For over 150 million years
When did Dinosaurs become extinct and why?
K-T extinction about 66 MYA by an Asteroid’s impact
What reptilian traits do birds still retain?
- Amniotic eggs
- have scales on legs
What are two major distinguishing traits for birds in relation to reptiles?
- Feathers
- Flight skeleton (bones are thin and hollow)
What are the three evolutionary novelties Birds Exhibit?
- Feathers
- Hollow Bones
- Physiological mechanisms for Flight
What is the first known bird?
Archaeopteryx
What do most paleontologist agree about birds being the direct descendants of?
Theropod dinosaurs
What are Land plants called?
Embryophyta
What are some characteristics of Land plants?
- multicellular eukaryotes with cellulose cell walls and a large central vacuole
- Photosynthetic
- Sexually reproducing with alternation of generations (haploid gametophytes and diploid sporophytes)
- Diploid embryo is protected and nurtured within the gametophyte
How did pants adapt to terrestrial life?
- waxy cuticle and stomata (protection from drying out)
- They can move water within plants
- They shift from diploid to haploid( protection against UV radiation)
What are the closest living descendants of first land plants called?
Bryophytes
What plant lacked tracheids, and had other conducting cells in gametophytes?
Nontracheophytes
What were important for enhancing water uptake?
mycorrhizal associations
What species is known to be the first vascular land plant?
Cooksonia
How did leaves make photosynthesis more efficient?
They increased surface area
How many times did leaves evolve?
Twice
1. Euphylls
2. Lycophylls
What are Lycophytes?
- They are sister group to all other vascular plants
- Leaves developed independently
- Sprophyte dominant
- Lack seeds
( most abundant in the tropics)
What are characteristics about Ferns?
They are the most abundant group of seedless vascular plants
How long have seed plants become dominate in the terrestrial landscape?
over the last several hundred million years
Where did seed plants evolve from?
spore-bearing plants known as (progymnosperms)
What are some benefits of the evolution of the seed?
- it protects food for embryo
- allow embryos to pause development and growth and germinate after harsh conditions have passed
How do seeds protect the embryo?
- there is an extra layer or two of sporophyte tissue
- hardens into seed coat
How are angiosperms united by a suite of synapomorphies?
- ovules are enclosed within a carpet
- double fertilization
- stamens with two pairs of pollen sacs
- features of gametophyte structure and development
What are some primitive (or plesiomorphic) floral features?
- flowers small
- pollination by small insects
- bisexual but easily becoming unisexual
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