Ch 20 part 2

Question 1

origin of first cells

Answer 1

Earth was hot, mostly ocean with volcanic gases and LOW O2

Question 2

Earliest evidence of life

Answer 2

oldest cell fossils of prokaryotes in stromatolite formations (layers of rock, specifically cyanobacteria)

Question 3

What does a new group/taxon begin with

Answer 3

1 ancestral species that arose through speciation, more microevolution, and more speciation/extinction

Question 4

Adaptive radiation

Answer 4

rapid increase in number of species due to great ecological and morphological diversity and new ecological niches, descend from ONE ancestor species. the ancestor species is isolated, acquires a new adaptation, and expands form there to create many species

Question 5

Exaptation

Answer 5

an adaptation that performs differently from its original function, ex. hair (insulation) to procupine quills (defense). Change in function, THEN form

Question 6

function of developmental genes

Answer 6

control development of multicellular organisms

Question 7

many developmental genes are

Answer 7

regulatory genes, which control the expression of 1+ genes

Question 8

how do dramatic changes in final form happen

Answer 8

mutation–> affects gene expression –> changes in final form

Question 9

heterochrony

Answer 9

changes in timing of development results in evolutionary change, also called allometric growth, due to mutation in developmental gene

Question 10

homeotic genes (hox)

Answer 10

are responsible for the development of body structures. a mutation in a homeotic gene can cause body structures to develop in the wrong area. this can be linked to changes in form

Question 11

relative dating

Answer 11

compares positions of strata (rock layers) to approximate date/sequence of structures

Question 12

absolute dating

Answer 12

numerical age of fossils: two types, radiometric dating (decay rate of isotopes) and half time (time for half isotope to decay)

Question 13

geologic time scale

Answer 13

hadean, arcane, proterozoic

Question 14

Hadeon Eon

Answer 14

planet formed, molten rock surface, no liquid water

Question 15

archaean eon

Answer 15

crust cooled, solidified, condensed water formed global ocean, volcanoes created first land, low O2, first life (prokaryotic cells), oxygen revolution, O2 rich atmosphere

Question 16

proterozoic eon

Answer 16

continents form as island merge, created areas of shallow seas, eukaryotic life began, first multicellular life

Question 17

Phanerozoic Eon

Answer 17

Paleozoic eon cambrian explosion of animal diversity, fishes, seedless plants, fungi, and arthropods invade land, vertebrates, amphibians, amniotes (shelled eggs), continental drift leads to Pangea, ends with permian mass extinction

Question 18

mesozoic era

Answer 18

dinosaurs and reptiles, cone bearing seed plants, first mammals and birds, breakup of Pangaea, cretaceous mass extinction

Question 19

cenozoic era

Answer 19

major divesritation of mammals, flowering plants, insects, birds, fist humans