The current classification system used by biologists
has three domains; is updated and revised whenever new information becomes available; is used for all living organisms (plants, animals, bacteria, fungi, and protist)
Which of the following is the cause of the current extinction crisis?
Human activities that involve altering habitats, changes in sea levels, and changes in weather patterns on a global scale are causing mass extinctions.
Allopatric speciation occurs when
populations are geographically separated.
The Cretaceous extinction, which lead to the extinction of the dinosaurs, was most likely due to
an large asteroid hitting the earth.
Which of the 3 domains do animals belong to?
The smallest or most specific level of biological classification is
_____________ is the loss of a species or taxonomic group from the planet.
Areas of the planet that support the highest number of species are known as ___________. Examples include coral reefs and tropical rain forests.
Which of the following can lead to sympatric speciation?
habitat differentiation; sexual selection; polyploidy
According to the biological species concept, the western spotted skunk and the eastern spotted skunk are two distinct species. This means that the two species
they do not interbreed.
The ___________ is the most used method since it defines a species as being one that is reproductively isolated from other species. This model only works if a species reproduces sexually and is currently alive.
biological species concept
The __________separates species based on differences in physical traits, or morphology (morph- means "form"). This is useful for studying the fossil record where you can't determine reproductive isolation. It is difficult to apply to organisms that do not leave fossil records.
morphological species concept
The ____________ traces the evolutionary history of the organism and its relatedness to other species through its traits. In this model, the study of an organism's traits and location on the evolutionary tree is a better indication of whether it is a unique species that the biological species concept.
phylogenetic species concept
________ is the identification and naming of species.
Species are identified by a two-part _____ name, such as Homo sapiens (humans) or Panthera orca (jaguar).
Scientists have attempted to ______ the total biodiversity on the planet.
One of those studies placed the total at around ____ million species, give or take ___ million. (This number does not include bacteria and viruses.)
___________, refers to not only the total number of a species in an area, but also how many different species are found in that area.
_________________ cover only 2.4% of the world's surface, but they account for over 50% of all plant and 42% of all animal species.
An _______ is an individual of one species
A ________ is a group of similar organisms that are reproductively compatible and capable of interbreeding and producing living offspring.
A _______ is a group of individuals of the same species living in the same area.
The biological species concept uses ______________ to designate separate species.
___________ is the formation of new species
_________ is when new species evolve rapidly after some event
In the _________ model, small changes occur periodically in a population until reproductive isolation occurs. Charles Darwin was a supporter of the gradual pace of speciation.
____________________, periods of no change (equilibrium) are interrupted (punctuated) by events that promote rapid speciation.
When geographic separation leads to speciation it is known as _________ ________.
Speciation can also occur when individuals are not physically separated; Species may also become isolated by differences is preferred resources or different times of the year for mating.
Barriers that prevent a mating attempt between two species are known as __________________.
prezygotic isolating mechanisms
If the barrier occurs after mating and fertilization it is known as a ________________.
postzygotic isolating mechanisms
Which of the following is a prezygotic isolating mechanism?
Speciation can occur...
rapidly; slowly; When species are geographically separated; When species are not geographically separated
The largest taxonomic group is a...
How many mass extinctions have occurred in Earth's history?
(True or False) Viruses are prokaryotic organisms
Which mode of prokaryote nutrition is similar to digestion in humans?
Which domains include prokaryotic organisms?
Domain Bacteria and Domain Archaea
Which of the following describes eukaryotic cells?
they have a nucleus; they have organelles; they have larger than prokaryotic cells
Protist belong to..
Animals are part of the supergroup...
A mutualistic relationship
Benefits both species
Which fungi phylum makes mushrooms?
Which of the following does NOT describe protist?
They can be autotrophic or heterotrophic
The phylum Basidiomycota produces mushrooms where are the ___________ of the fungi.
When plants evolved and moved onto land 500MYA which of the following would have been a challenge?
The dominant generation in angiosperms is
Where does coal come from?
Dead plant material
Which group of plants evolved first?
Fems have all of the following except
During the age of the dinosaurs the main plant groups would have been...
Seedless vascular plants and gymnosperms
Fungi obtain nutrients through....
In an experiment done with 2 species of cichlid fish, females were unable to recognize males of their own species under monochromatic light. This shows that females are choosing males based on color differences only. This is an example of...
Sexual selection can lead to
The diversity of life is often portrayed as a tree to provide a simple visualization of evolutionary relationships
Tree of Life
Scientists refer to these trees as ________
Currently, all organism fall into one of three domains..
______ refers to a single-celled organism that lacks a nucleus and internal membrane-bound organelles.
Prokaryotes are commonly called _______, there are prokaryotes that are not true bacteria
Prokaryote reproduce asexually by a process known as ______ ______.
This results of binary fission are __________.
two identical cells
Prokaryotic cells have evolved to have almost every form of metabolism and have the _________ from a variety of different means
ability to obtain nutrients and energy
Cells that use solar energy to manufacture their own food.
Cells that use the sun for energy, but also use organic materials as the building blocks of their food.
Cells that use other energy sources, such as hydrogen gas, to obtain the energy to manufacture their own food.
Cells that use the breakdown of organic material to supply energy and the materials needed to manufacture food.
______________ experiments supported the idea that conditions on early earth could have led to the creation of organic molecules necessary for early life.
The oldest prokaryotes fossils date back ________.
First prokaryotes were ______
_________ prokaryotes evolved later and added oxygen to the atmosphere.
Bacteria are the ____________________________.
oldest organisms on the planet
Bacteria are classified based on...
shape, metabolic abilities, and similarities in their DNA
________ are a unique form of prokaryotes that have adapted to life in environments that are often hostile to other organisms, such as geysers and hot springs (extremophiles)
We currently know of ___________ of archaeans
three different types
tolerate environments with extreme heat and sulfur content.
live in oxygen-free environments such as swamps and the intestinal tracks of livestock.
survive in high-salt habitats, such as the Dead Sea or Great Salt Lake.
All _______ are eukaryotes
All protists posses
a nucleus containing DNA; membrane-bound organelles, such as mitochondria and endomembrane system
Protists can be....
Single-celled; Form colonies; Multicellular structures (like algae)
Protists are single cells, or collections of cells, that __________ associated with other eukaryotic organisms
do not form the tissues
All protists can be ________ or _______ or _____
autotrophic; heterotrophic; both
First protists evolved from the prokaryotes toward the end of the _________ ______ about 800 million to 1 billion years ago
Protists were placed into a single kingdom, called _______ ______, as single-celled eukaryotes.
Divisions within the protists were typically assigned based on whether the organisms were.....
autotrophs; heterotrophs; saprophytic (feed on dead or decaying material).
Protist are now organized into ________
it is unlikely that all protist share a _________________.
common evolutionary history.
Some protists are more _______, others are more like fungi or animal-like
Examples of supergroup: Excavata are
Examples of supergroup: Chromalveolata are
dinoflagellates, gold and brown algae, sporozoans
Examples of supergroup: Rhizaria are
Examples of supergroup: Archaeplastida are
red and green algae, land plants
Examples of supergroup: Amoebozoa are
amoebas, slime molds
Examples of supergroup: Opisthokonta are
fungi, choflagellates, animals
Name the Eukaryotic supergroups
Opisthokonta, Amoebozoa, Archaeplastida, Rhizaria, Chromalveolata, and Excavata
_______ consists of protists that have either lost or reduced their mitochondria (although they had them in the past) and possess a long oral groove for feeding
_______ includes the dinoflagellates, which release the toxins that cause red tide in the oceans, and the parasitic sporozoans.
______ consists of foraminifera and radiolarians, which form external structures called tests made of calcium carbonate or silicon.
_________ includes the photosynthetic red algae, green algae, and the land plants. The green algae are the ancestors of the modern plants.
________ consists of the ameoba-like organisms that move using cellular extensions called pseudopods.
________ consists of flagellated cells, such as choanoflagellates. This supergroup also contains the animals and fungi.
________ make up phytoplankton, Red and green algae are eatable
Forams are useful in the field of paleontology
Most fungi are ________
Fungi are composed of microscopic filaments, called ________ that collect to form multicellular structures called ________.
A "__________" is a portion of the mycelium that has been dedicated to reproduction.
Not all fungi _______ mushrooms.
The mushroom you see in the supermarket is a ________.
Fungi are often considered microbes because their "body" cannot usually be seen without a _______.
Fungi are all _______ organisms; they get their nutrients from organic material.
Fungi are ________; they ________ their food, unlike animals that ingest their nutrients.
For many fungi, being a ____________ means that it absorbs dead or decaying material, such as logs or leaves in the forest.
In fungi, only the zygote is diploid, and all other stages of the life cycle are _______
During asexual reproduction, each mycelium produces _______, where _____(haploid) formation occurs.
______ are resistant to environmental factors, such as drought and cold, and may be dispersed by the wind. If they encounter a moist environment, they germinate into new mycelia.
Fungi have _______ instead of true sexes.
Sexual reproduction in fungi involves the ________ from different mating types. Depending on the type of fungi, a fusion of these two different hyphae creates a reproductive structure.
Animals and fungi are both in the _________ and are more closely related to each other than either are to plants.
Fungi generally do not produce fossils well, so it is _______________________________________.
difficult to estimate from fossil records when they first evolved.
The earliest known fossil fungi are dated at _____, but fungi probably evolved a lot earlier.
The first plants on land ____________ in symbiotic relationships, such as the mycorrhizae.
most likely brought fungi with them
diverse group of fungi; includes bread molds; other species are parasites of insects
commonly called the sac fungi; possess sac-like fruiting body, called an ascocarp; includes the yeasts and some forms of molds, morels and truffles.
club fungi; are what people usually envision when someone says the word "mushroom“
Fungi can also form mutualistic symbiotic relationships with the roots if plants, known as ________.
Mycorrhizae provide plants with __________________________________________.
minerals and nutrients from the soil such as nitrogen
Benefits that Humans get from Fungi include...
Decomposition of dead organic material; Production of beer, wine, and bread, some cheese; Antibiotics such as Penicillin (Ascomycota)
We rely on plants for _______
food, fuel, shelter, and medicine
Plants are an important part of the ______ that flows through ecosystems and most nutrient cycles
All plants are __________________.
Produce their own food by the process of _________
Cell properties of a plant:
Store energy as starch; Have cell walls made of cellulose
Plants belong to the _______________, along with the red and green algae.
DNA evidence suggests that the plants evolved from a type of aquatic green algae called the _______ around 500 MYA.
Vascular tissue of a plant:
Internal transportation system of plants; includes tissues called xylem and phloem
Allows the plant to transport water, minerals, and food to its tissues while also allowing the plant to remain in an erect position on land
Leaf size of a plant:
Microphyll - small, narrow leaf, which prevents water loss but limits photosynthesis; Megaphyll - evolution of larger leaves with protective coatings and more efficient gas exchange mechanisms increases photosynthetic output
Seeds of a plant
Represent a more efficient means of reproduction over spores; Contain an embryo and stored organic nutrients within a protective coat, that prevent the plant embryos from drying out
Flowers of a plant
Reproductive structure found only in the angiosperms; Attract pollinators, such as insects, and give rise to fruits that cover seeds
Bryophytes include all plants that lack vascular tissue: Includes mosses, hornworts, and liverworts.
The dominant stage of a bryophyte is the ________, the green “leafy” part, which produces the gametes.
The sporophyte stage produces _________.
include the lycophytes (club mosses) and the more common ferns.
Pterophytes were the..
first group of plants where the dominant stage was the sporophyte.
__________ were the first plants with leaves, called microphylls, and vascular tissue—the internal transportation system of plants.
Lycophytes and ferns use _____ as the method of dispersing their spores for asexual reproduction.
Pterophytes were most numerous during the......
Carboniferous period (300 – 360MYA).
Pterophytes fossilized remains....
eventually turned into coal.
________ are the most abundant and diverse land plants on the planet.
Seed plants include _________ and _________.
gymnosperms (naked-seed plants); angiosperms.
Seed plants have two types of spores that produce two types of microscopic gametophytes; The male gametophyte is the _________ and it produces sperm. The female gametophyte is the _______, which produces and houses the egg.
pollen grain (1n); ovule (1n)
Pollination occurs before ____________________________.
fertilization and happens only in seed plants
Pollen can be spread by wind or animals; This represents a major adaptation to the land environment by the seed plants since it ______________________
separates reproduction from a need for a water environment.
Angiosperms are ________________________________; Their success is due to flowers, which attract pollinators, protect the embryo, and provide nourishment in the form of stored nutrients in fruits and seeds.
(covered seed plants) are the most successful of all plants, with over 352,000 species
The majority of angiosperm species are _____ on pollinators to transfer pollen from one plant to another.
Some relationships between some angiosperms and their pollinators have evolved to be ________.
Animals are the branch of the Eukarya tree that contains_________________
multicellular heterotrophic organisms.
Animals differ from plants and fungi in several ways:
they ingest (eat) their food; they contain cells that lack a cell wall; they are motile (able to move); they have a life cycle in which, in many cases, diploid adults produce haploid gametes (egg and sperm) for reproduction
Animals belong to the __________
The first animals most likely evolved from _________ similar to modern-day choanoflagellates
The first animals appear in the fossil record around ______.
Most major animal body plans evolved during the__________
Cambrian Explosion around 500 MYA.
One of the best ways to understand the evolution of animals is to study their ________
Animals are generally grouped by shared characteristics
Symmetry; Number of tissue layers; Absence/presence backbone; Type of body cavity
symmetry around a central axis, as in a starfish or a tulip flower.
the property of being divisible into symmetrical halves on either side of a unique plane.
_________________ are the simplest of the animals. They lack any symmetry, specialized tissues, or the nerve and muscle cells, that are found in the remainder of the animals. Their bodies are made-up of many cells with distinct functions.
_________________ are the first of the Eumetazoans or true animals. Jellyfish generally possess radial symmetry. Jellyfish also have two tissue layers, which leads to an increased specialization of cells.
________________ are the first group of animals that exhibit bilateral symmetry, which means that they have a distinct head region where sensory organs are located. They have no body cavity (acoelomates)
Lack of an internal body cavity and therefore very few internal organs.
The cavity is just a space between the mesoderm and endoderm tissue layers and is therefore called "false." These organisms may have some internal organs.
True body cavity formed by the splitting of the mesoderm. This arrangement allows for the formation of specialized tissues and organ systems
___________ are the first examples of coelomate organisms, with complex body plans, and well-developed organ systems
Molluscs all have bodies composed of at least three distinct parts:
visceral mass ; a foot; a mantle
the soft interior of the organism that contains internal organs
a strong, muscular organ used for locomotion
a membranous or muscular covering that envelops the visceral mass
Organisms such as snails and coaches. Snails may have lungs and be terrestrial.
Organisms such as octopus, squid and natiluses in which the foot has evolved to form tentacles around the head. Some of the most intelligent animals in the ocean.
Organisms such as clams, scallops, and oysters that have two parts to their shell
Many molluscs are endangered due to _______
habitat loss, invasive species, pollution, overharvesting, and climate change
________ are scavengers (earthworms), predators (clam worms), or parasites (leeches).
Nematodes feed on __________
algae, fungi, microscopic animals, and dead organisms.
Which of the following is not a characteristic of a prokaryote?
Prokaryotic cells can be classified by their nutritional mode. A chemoheterotroph is an organism that uses ______ for energy, similar to animals
Which supergroup consists of protists that are photosynthetic and includes green and red algae?
Fungi are saprobes. This means they
absorb dead or decaying material for nutrients.
The fungi that produce white and portabello mushrooms belong to the phylum
Which group of plants lack vascular tissue and include mosses, hornworts, and liverworts?
do not have a backbone; include molluscs and arthropods; include flatworms, segmented worms, and round worms.
Which phylum is the only one with members that exhibit radial symmetry and the first to have true tissue?
Which group of vertebrates does not produce an amniotic egg?
Both __________ and ______ must shed to grow
are the most successful and diverse animals on the planet.
Arthropods share common characteristics:
jointed appendages; external exoskeleton made of chitin; Segmentation (head, thorax, abdomen; Well-developed nervous system; Respiratory organs (gills, book gills, tracheae); Metamorphosis from larva to adults
Live marine and aquatic environments and have an exo skeleton that contains calcium carbonate and chitin. Examples are shrimp, crabs, and lobsters.
Arthropods with three pairs of legs and possibly one or two pairs of wings. The presence of wings enhances te ability to survive and provides a means of finding food, facilitating mating, and dispersing offspring. Examples are flies, butterflies, grasshoppers and beetles.
Predatory arthropods whose first pair of appendages are the pincerlike chelicerae, used in feeding and defense. Examples are spiders and scorpions.
Centipedes and Millipedes
Centipedes possess one pair of legs per segment and are predators of worms and insects. Millipedes possess two pairs of legs per segment are herbivores.
Over _________ of arthropods are endangered or threatened; mainly due to habitat loss
Many insect arthropods, such as bees, are important pollinators. A loss of pollinators effects ________________________.
angiosperms and can also impact humans.
common name sea stars, are generally called starfish.