Biology Questions and Answers
- Evolutionarily
protochordates may be
intermediate animals between
invertebrates and vertebrates.
Imagine a scientist is testing
the hypothesis that
vertebrates evolved from
echinoderms. Having as
research object a newly found
protochordate species, what is
an example of a discovery that
would weaken the hypothesis?
What is an example of a
discovery that would
strengthen it?
Hypothesis to be tested: evolved from echinoderms. TVertebratesesting
material: A newly found protochordate
species (i.e., a vertebrate forerunner).
Example of weakening observation (that
puts the new protochorevolutionarily far from echidate spnoderms):ecies (^)
“The new species is protostome”, as
opposed to echinoderms, that ardeuterostomes. This observation be (^) rings
the suspicion that deuterostomy in
vertebratfrom echinoderms.es is independent in origin
Example (that nears thof strengthe new protochoening observationrdate
species to ecspecies has secohinoderms): “Tndary radialhe new
symmetry”, similar to echinoderms. This
observation hypothesis that emakes strongchinoderms ander the (^)
vertebrates are relatives.
(This item shows hbeginning with the placemow science works,ent of
hypothesis and further observationaltesting.)
- Chordate identity card.
How are they characterized
according to examples of
representing beings, basic
morphology, type of
symmetry, germ layers and
coelom, digestive system,
respiratory system, circulatory
system, excretory system,
nervous system and types of
reproduction?
Examples of representing beings:
protochorvertebrates. Basic morphology:dates (ascidians, amphioxus),
branchial clefts, notochord, neural tube.
Type of symmetry:layers and coelom: bilateral. Germtriploblastics,
coelomates.complete, deuterostomes. Res Digestive system:piratory (^)
system: branchial (in aquatic),
cutaneous (ipulmonary (othn adult amphibians),ers). Circulatory system: (^)
open in protochordates, closed in
vertebratand flame cells in es. Excretory system: dprotochordates,iffusion
kidneys in vertebrates. Nervous system:
neural tube in embryos, cerand single ganglion in protochorebral vdates,esicle
brain within the cranium and spinal cord
within Types of reproduction: sexual, with the spinal column in vertebrates.or
without larval stage.
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