BIO Ch 17: The History of Life
in 1953, the _____-_____ experiment showed a possible origin of organic molecules
Miller-Urey
one species of _____ harbors symbiotic algae, supporting the endosymbiotic hypothesis
Paramecium
animal diversity arose in the ____ Era
Precambrian
Earth may have once been an _____ world
RNA
_____ can act as a catalyst
RNA
_____ may have been the first self-reproducing molecule
RNA
_____ may have served as both an information-carrying molecule and an enzyme catalyst for its own replication
RNA
by the ____ period, life in Earth's seas included an array of anatomically complex animals
Silurian
early amphibians had _____ ____, which are like primitive lungs
air sacs
_____ evolved from lobe-finned fishes
amphibians
the first organisms were _____ (aerobic, anaerobic) prokaryotes and probably absorbed nutrients from the _____
anaerobic environment
flowering plants enticed _____ to carry pollen
animals
the first animals to move onto land were ____ (the group that today includes insects, spiders, scorpions, centipedes, and crabs)
arthropods
when animals became adapted to life on dry land, _____ were the first to invade land
arthropods
reptiles have trouble retaining _____ _____
body heat
_____ may have catalyzed the formation of larger organic molecules
clay
_____ change contributed to mass extinctions
climate
____ protected their developing seeds inside cones
conifers
_____ were the earliest seed-bearing plants
conifers
one cause of climate change is _____ drift
continental
early amphibians had muscular fins that allowed
crawling
_____ dominated the earth for millions of years
dinosaurs
some plants became adapted to life on ____ land
dry
the _____hypothesis proposes that early eukaryotic cells acquired the precursors of mitochondria and chloroplasts by engulfing certain types of bacteria
endosymbiont
the _____ ______ proposes that early eukaryotic cells acquired the precursors of mitochondria and chloroplasts by engulfing certain types of bacteria
endosymbiont hypothesis
the _____ of arthropods facilitated survival
exoskeleton
____ provided support for animals' bodies and protection from predators
exoskeletons
_____ are hard outer coverings that help protect animals that have them
exoskeletons
_____ improved mobility by providing hard surfaces to which muscles attached. These attachments made it possible for animals to use their muscles to move appendages used to swim through the water or crawl over the seafloor
exoskeletons
evolutionary history has been marked by periodic mass _____
extinctions
insulating _____ retain body heat for birds
feathers
____ proved to be faster than invertebrates, with more acute senses and larger brains. Eventually, they became the dominant predators of the open seas
fish
feathers evolved for ____
flight
insulating _____ retains body heat for mammals
hair
the time it takes for half of a radioactive element's nuclei to decay at a rate that is independent of temp., pressure, or chemical compound is called its _____ _____
half life
Each radioactive element decays at a rate that is independent of temperature, pressure, or the chemical compound of which the element is a part. The time it takes for half of a radioactive element's nuclei to decay is called it's ____ ____
half-life
the internal membranes of eukaryotes may have arisen through _____ of the plasma membrane
infolding
pollination of plants is facilitated by _____
insects
the internal membranes of eukaryotic cells may have originally arisen through ____ ____ of the cell membrane of a sing-celled predator
inward folding
_____ and _____ can form membrane-like vesicles
lipids proteins
a support of the endosymbiont hypothesis comes from ____ ____, organisms alive today that are similar to hypothetical ancestors and this help show that a proposed evolutionary pathway is plausible
living intermediates
_____ bear live young and have mammary glands to nourish them
mammals
_____ invertebrates dominated during the Precambrian Era
marine
_____-like vesicles may have enclosed ribozymes
membrane
some organisms acquired _____-enclosed organelles
membrane
_____ and _____ may have arisen from engulfed bacteria
mitochondria chloroplasts
coevolution of predator and prey favored animals that were more ____ than their predecessors
mobile
_____ and _____ were the first plants to evolve on land
mosses ferns
some algae became _____
multicellular
the first living things arose from _____ things
non living
aerobic metabolism arose in response to the _____ crisis
oxygen
_____ increased the amount of oxygen in the atmosphere
photosynthesis
_____ bacteria set the stage for the evolution of an oxygen-rich environment
photosynthetic
the potential rewards for terrestrial life were especially great for ____
plants
continental drift is caused by _____ _____, in which the Earth's surface moves slowly and land changes places
plate tectonics
seed plants encased sperm in _____ grains
pollen
organic molecules can form spontaneously under ______ conditions
prebiotic
the period in which life began is known as the _____ era
precambrian
_____ favored the evolution of improved mobility and senses
predation
______ are organisms whose genetic material is not enclosed in a membrane-bound nucleus AND they lack other membrane-bound organelles
prokaryotes
the first cells to arise in Earth's oceans were _____, cells whose genetic material was not contained within a nucleus
prokaryotes
a ____ is structurally similar to a cell but not alive
protocell
if a vesicle happened to surround the right ribozymes, could explain the possible origins of cell-like structures called
protocells
_____ evolved from amphibians
reptiles
_____ evolved shelled eggs, water-resistant skin, and fully-functional lungs
reptiles
_____ gave rise to mammals
reptiles
one group of _____ evolved into birds
reptiles
_____ are RNA molecules that can catalyze a variety of reactions involving RNA
ribozymes
_____ improved mobility and protection
skeletons
primitive land plants retained swimming ____ and required water to reproduce
sperm
in the mid-1800s, the idea of _____ _____ was refuted by Louis Pasteur and John Tyndall
spontaneous generation
life was thought to have developed from living and nonliving matter through _____ _____
spontaneous generation
evidence for the endosymbiont hypothesis is ____ (strong/weak)
strong
early amphibians were still dependent on _____ for survival and reproduction
water
once _____ was available, the prebiotic evolution that ultimately led to the first living organism could begin
water
primitive land plants were still dependent on _____ for reproduction
water
____-____ coatings on above ground parts (of land plants) reduced water loss by evaporation, and rootlike structures delved into the soil, mining water and minerals
water-resistant
during the ____ period, the flowering plants appeared, having evolved from a group of conifer-like plants
Cretaceous
the earliest seed-bearing plants appeared in the late ____ period and produced their seeds along branches, without any specialized structures to hold them
Denovian
* 2 ways an organism larger than a millimeter in diameter can survive: 1.) have a low metabolic rate so that it doesn't need much oxygen or produce much carbon dioxide; 2.) be multicelluar
...
* Earth was cool enough for water to exist in liquid form by 4.3 billion years ago. Once liquid water was available, the prebiotic evolution that ultimately led to the first living organisms could begin
...
* Eventually, the endosymbiotic bacterium lost its ability to live independently of its host and the mitochondrion was born. It then captured a photosynthetic bacterium and again failed to digest its prey. The bacterium flourished in its new host and gradually evolved into the first chloroplast
...
* The eggs of seed plants were retained on the parent plant and the sperm were encased in drought-resistant pollen grains that were carried by the wind from plant to plant. When the pollen grains landed near an egg, they released sperm cells directly onto living things
...
* The evolution of efficient movement was often associated with the evolution of greater sensory capabilities and more complex nervous systems. Senses for detecting touch, chemicals, and light became highly developed, along with nervous systems capable of handling the sensory information and directing appropriate behaviors
...
* extra thick walls (of land plants) surrounding certain cells enabled stems to stand erect
...
* multicellularity provided 2 advantages: 1.) large, many-celled algae would have been difficult for single-celled predators to engulf; 2.) specialization of cells would have provided the potential for staying in one place in the brightly lit waters of the shoreline, as rootlike structures burrowed in sand or clutched onto rocks, while leaflike structures floated above the sunlight
...
* significant amounts of oxygen first appeared in the atmosphere about 2.3 billion years ago, produced by bacteria that were probably very similar to modern cyanobacteria
...
* some algae gave rise to the first multicellular land plants
...
* specialized cells (of land plants) formed tissues (called vascular tissues) that contained tubes to conduct water from roots to leaves
...
* the earliest cells were primitive anaerobic bacteria
...
* the earliest plants were restricted to swamps and marshes or to areas with abundant rainfall; here the sperm and eggs could be released into the water, and sperm could swim to reach an egg
...
* the full range of modern invertebrate animals does not appear in fossil record until the Cambrian period, marking the beginning of the Paleozoic era, about 542 million years ago
...
* the oldest fossil organisms found so far are in rocks that are about 3.4 billion years old
...
* the plants that first colonized the land would have had ample sunlight, untouched nutrient sources, and no predators
...
* water-based photosynthesis converts water and carbon dioxide to energetic molecules of sugar, releasing oxygen as a byproduct; the emergence of this new method for capturing energy introduced significant amounts of free oxygen to the atmosphere for the first time
...
*photosynthesis requires a source of hydrogen
...
the rise of eukaryotes began about _____ billion years ago
1.7
the oldest fossil organisms found so far are in rocks that are about _____ billion years old
3.4
almost all of the major groups of animals on Earth today were already present in the early _____
Cambrian
the _____ period was characterized by vast forests of giant tree ferns, club mosses, and horsetails
Carboniferous
