Week 15 Flashcards
(32 cards)
Of the following challenges faced by vertebrates moving from an aquatic to a terrestrial environment, which one was the most important?
Preventing the body from drying out
Amphibians have successfully invaded the land; however, most are tied to water for _____.
Blank 1: reproduction, reproducing, breeding, or reproduce
Which of the following was one of the biggest challenges to amphibians as they adapted to life on land?
Dehydration
Tetrapods spread from North America to Asia after the supercontinent, _____ , was formed
Pangea
Tiktaalik was probably an intermediate between ____
and tetrapods.
fish
Which of the following are challenges amphibians had to overcome when adapting to a life on land?
Obtaining enough oxygen without using gills
Prevent body from drying out
Needing water to complete the reproduction cycle
Delivering enough oxygen to muscles needed for land movement
Moving a large body mass without being buoyant in water
Which of the following accurately describe why amphibians are tied to water for reproduction?
To prevent eggs from drying out
Tetrapods became common during the ____
period (360 to 289 MYA).
Carboniferous
As ______were the first vertebrates to adapt to a _____ life, one of their biggest challenges was to prevent their bodies from drying out.
Blank 1: amphibians
Blank 2: terrestrial or land
Identify the three orders of amphibians:
Blank 1: Anura
Blank 2: Caudata
Blank 3: Apoda
The earliest fossils of the first tetrapods were found in what area?
Greenland
Which of the following amphibians do not have tails?
Frogs
Toads
The fossil, ____ , discovered in Canada in 2006 had gills and scales like a fish but a neck like an amphibian.
Tiktaalik
Larval salamanders have external gill and gill slits. During metamorphosis what happens to these structures?
They disappear.
Which amphibians are legless, wormlike creatures with small eyes and are often blind?
Caecilians
In the early Permian period, the tetrapods began migrating from marshes to which of the following habitats?
Dry uplands
The ______ egg is considered to be a “key innovation” because it permitted animals to lay their eggs in a greater variety of environments.
amniotic
During the ______
period, moist-skinned amphibians successfully invade the wet habitats world wide.
Tertiary
Identify the type of reproduction carried on by frogs and toads.
Sexual, external fertilization
Most salamanders practice which of the following types of reproducion?
Sexual, internal fertilization
Which order of amphibians includes a highly specialized group of tropical burrowing amphibians that are the Caecilians?
Apoda
What are the three orders of living amphibians?
i) Caecilians;
ii) Newts and Salamanders,
iii) Frogs and toads.
What does evidence from DNA sequencing tell us about Frog/Toad relations?
Evidence from DNA sequences suggests that the Frogs/Toads are more closely related to Salamanders, than Caecilians.
How far do Caecilian, Salamanders and frogs date?
From the fossil record, the earliest Caecilian is from the Early Jurassic (176-200 MYA), the earliest salamander is from the mid Jurassic (161-176 MYA) and the earliest frogs from the late Triassic (200-228 MYA).
However, as is usually the case, molecular DNA evidence (using molecular clocks) show that the divergences occurred earlier than the fossil evidence suggests.
Molecular clock evidence suggests these started to diversify from one another around the Carboniferous period (~350 MYA) during the Palaeozoic Era.
The basal divergence of the living members of the three living orders seems to have taken place around 250 MYA.
