Question | Answer |
_______ are the naturally preserved remains, imprints, or traces of organisms that lived long ago. | Fossils |
Examples of fossils include _____, shells, and footprints. | bones |
A _______ is a scientist who studies fossils. | paleontologist |
The process of _______ is part of an organism’s life cycle. | decomposition |
Decomposition breaks things down into _____ that can be used by other organisms. | substances |
Organisms that consume and help break down dead organisms are known as _______. | decomposers |
_______ eat dead organisms. | Scavengers |
To become a _____ , a dead organism must be well protected from decomposers, scavengers, and environmental factors. | fossil |
Organisms with hard structures such as _____, bones, and shells are more likely to become fossils. | teeth |
Fossils only form under _____ conditions. | certain |
In the _______ process, minerals are deposited in the empty spaces of dead organisms. | permineralization |
Permineralization forms strong, _____ fossils. | rock-like |
Most _____ become fossilized through permineralization. | bones |
The details of the organism’s hard structure are often ______. | preserved |
_____ wood refers to trees that are fossilized by permineralization. | Petrified |
In the _______ process, the hard parts of an organism are dissolved and replaced with minerals. | replacement |
The original microscopic details of the organism are partially or totally ______. | destroyed |
Only the ____ of the original organism remains. | shape |
______ occurs when a dead organism is quickly buried under conditions without oxygen. | Carbonization |
A thin film of _____ is left behind when hydrogen, oxygen, and nitrogen leave a dead organism’s remains. | carbon |
The carbon film preserves an _____ or shape of the original organism on a rock. | image |
Many ____ fossils are preserved as carbon films. | plant |
Soft animal materials such as ____, fur, and feathers can be preserved as carbon films. | skin |
The preservation of an impression or indentation of an organism is a ____ or a cast. | mold |
Mold and cast fossils contain ___ remaining parts of the original organism. | no |
A cast is formed when a ___ fills with sediment that hardens into rock. | mold |
Casts are formed entirely from material ___ than the original organism. | other |
In an ____ ____ fossil, none of the hard or soft structures of the organism have been altered or replaced. | original material |
The organism is preserved in its ____ form. | original |
Much of the evidence for ____ comes from fossils. | evolution |
Fossils provide a ____ of the different organisms that lived in the past. | record |
___ fossils are found in deeper sedimentary rock layers. | Older |
The ___ ____ is all of the known fossils, their placements in rocks, and their positions in time. | fossil record |
The fossil record supports the ____ of plants and animals. | evolution |
The fossil record has ___ in it. | gaps |
Most of the species that ever lived on Earth are now _____. | extinct |
Fossil evidence can sometimes be used to determine if an organism lived ____ or in groups, the kind of food it ate, and the type of environment it lived in. | alone |
The study of the similarities and differences in the structures of organisms is known as ___ ___. | comparative anatomy |
In 1976, scientists found fossils of four-winged true flies that confirmed an earlier prediction that true flies and scorpion flies have a common ____. | ancestor |
Evidence from the study and comparison of the structures of ____ organisms with those of fossils supports the pattern of evolution. | living |
Parts of organisms that are similar in origin and structure are called ___ ___. | homologous structures |
Homologous structures are the result of ____. | evolution |
Homologous structures may indicate how closely two or more species share common _____. | ancestors |
___ ___ appear similar, but have different ancestral origins. | Analogous structures |
Examples of analogous structures include the ___ of birds and insects. | wings |
Analogous structures result when similar ____ conditions produce similar natural selection outcomes over time on remotely related organisms. | environmental |
____ structures are structures that have no function in their present-day form. | Vestigial |
Scientists hypothesize that the vestigial structures once functioned in an ____. | ancestor |
_____ is the science of the development of embryos from fertilization to birth. | Embryology |
Similar patterns of embryo development provide clues to the _____ relationships among organisms. | evolutionary |
Embryos of different ____ have similar early developmental stages. | vertebrates |
The ___ ___ of vertebrates develop into facial and neck structures. | pharyngeal pouches |
The similarities of species are best explained by common ___ and by evolution through natural selection. | ancestors |
____ data supports the theory of evolution through natural selection. | Molecular |
Differences in the cytochrome c molecules of different organisms are ____ to have developed independently from different ancestral lines. | unlikely |
Earthquakes are evidence that changes to Earth’s ___ ___ are still occurring. | lithospheric plates |
As lithospheric plates ___, they create environmental changes for the organisms that live on and near them. | move |
Environmental changes caused by moving plates can lead to the development of and extinction of ____. | species |
___ ___ occurs when populations of species are divided or separated by a physical barrier. | Geographic isolation |
Geographic isolation can occur when lithospheric plates collide and form _____. | mountains |
___ and large bodies of water can also cause geographic isolation of species. | Rivers |
Once separated by geographic isolation, species may follow different ____ paths if they are in different environments over time. | evolutionary |
Darwin’s observations in ____ and Ecuador led to the idea of evolution by natural selection. | Galápagos |
When species evolve independently under similar conditions and develop structural and functional similarities, the process is known as ___ ___. | convergent evolution |
Convergent evolution results in very distantly related species that appear ____. | similar |
Geographic isolation leads to closely related species that appear ___. | different |
____, a Greek philosopher, was one of the first people to put organisms into categories. | Aristotle |
In the mid-eighteenth century, Swedish botanist ___ ___ developed a classification system that grouped organisms based on similar physical structures. | Carolus Linnaeus |
A ___ includes organisms that have the greatest number of traits in common and that can breed to produce fertile offspring. | species |
Only ___ are subject to natural selection and evolve. | species |
Linnaeus developed a system for ___ species that is still used today. | naming |
Each species has a ____ scientific name. | two-word |
The first word in the scientific name identifies the ___ to which the species belongs. | genus |
Organisms are ___ into levels. | classified |
The order of classification levels (from most general to most specific) is kingdom, ___, class, order, family, genus, and species. | phylum |
There are ___ different kingdoms. | six |
Basic features, such as whether an organism is single-celled or multicellular, are used to define each ___. | kingdom |
____, the modern study of classification, uses DNA and molecular biology to identifyrelated organisms. | Systematics |
The more shared __ sequences two species have, the more recent an ancestor they are likely to share. | DNA |
A ___ is the sequence of a sample of 1,000 base pairs of DNA. | haplotype |
DNA ____ measures the differences in overall DNA between two organisms. | hybridization |
Prompted by discoveries made in molecular biology, a new level, the ___, is now the highest level, positioned above kingdom. | domain |