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?
Domain Eukarya
The smallest or most specific level of biological classification is
species
_____________ is the loss of a species or taxonomic group from the planet.
Extinction
Areas of the planet that support the highest number of species are known as ___________. Examples include coral reefs and tropical rain forests.
biodiversity hotspots
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.
Taxonomy
Species are identified by a two-part _____ name, such as Homo sapiens (humans) or Panthera orca (jaguar).
Latin
Scientists have attempted to ______ the total biodiversity on the planet.
estimate
One of those studies placed the total at around ____ million species, give or take ___ million. (This number does not include bacteria and viruses.)
8.7; 1.3
___________, refers to not only the total number of a species in an area, but also how many different species are found in that area.
Biodiversity
_________________ cover only 2.4% of the world's surface, but they account for over 50% of all plant and 42% of all animal species.
Biodiversity hotspots
An _______ is an individual of one species
organism
A ________ is a group of similar organisms that are reproductively compatible and capable of interbreeding and producing living offspring.
species
A _______ is a group of individuals of the same species living in the same area.
population
The biological species concept uses ______________ to designate separate species.
Reproductive isolation
___________ is the formation of new species
Speciation
_________ is when new species evolve rapidly after some event
Adaptive radiation
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.
gradualistic
____________________, periods of no change (equilibrium) are interrupted (punctuated) by events that promote rapid speciation.
punctuated equilibrium
When geographic separation leads to speciation it is known as _________ ________.
allopatric speciation
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.
sympatric speciation
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?
Hybrid sterility
Speciation can occur...
rapidly; slowly; When species are geographically separated; When species are not geographically separated
The largest taxonomic group is a...
Domain
How many mass extinctions have occurred in Earth's history?
5
(True or False) Viruses are prokaryotic organisms
False
Which mode of prokaryote nutrition is similar to digestion in humans?
Chemoheterotroph
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..
Domain Eukarya
Animals are part of the supergroup...
Opisthokonts
A mutualistic relationship
Benefits both species
Which fungi phylum makes mushrooms?
Basidiomycota
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.
Reproductive Structure
When plants evolved and moved onto land 500MYA which of the following would have been a challenge?
Gravity
The dominant generation in angiosperms is
Diploid (sporophyte)
Where does coal come from?
Dead plant material
Which group of plants evolved first?
Bryophytes
Fems have all of the following except
Seeds
During the age of the dinosaurs the main plant groups would have been...
Seedless vascular plants and gymnosperms
Fungi obtain nutrients through....
Absorption
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
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 ________
phylogenetic trees
Currently, all organism fall into one of three domains..
______ refers to a single-celled organism that lacks a nucleus and internal membrane-bound organelles.
Prokaryote
Prokaryotes are commonly called _______, there are prokaryotes that are not true bacteria
bacteria
Prokaryote reproduce asexually by a process known as ______ ______.
binary fission
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
Photoautotrophs
Cells that use solar energy to manufacture their own food.
Photoheterotrophs
Cells that use the sun for energy, but also use organic materials as the building blocks of their food.
Chemoautotrophs
Cells that use other energy sources, such as hydrogen gas, to obtain the energy to manufacture their own food.
Chemoheterotrophs
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.
Miller-Urey
The oldest prokaryotes fossils date back ________.
3.5 MYA
First prokaryotes were ______
anaerobic
_________ prokaryotes evolved later and added oxygen to the atmosphere.
Photosynthetic
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)
Archaean
We currently know of ___________ of archaeans
three different types
Thermophiles
tolerate environments with extreme heat and sulfur content.
Methanogens
live in oxygen-free environments such as swamps and the intestinal tracks of livestock.
Halophiles
survive in high-salt habitats, such as the Dead Sea or Great Salt Lake.
All _______ are eukaryotes
protists
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
Precambrian period
Protists were placed into a single kingdom, called _______ ______, as single-celled eukaryotes.
Kingdom Protista
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 ________
Supergroups
it is unlikely that all protist share a _________________.
common evolutionary history.
Some protists are more _______, others are more like fungi or animal-like
plant-like; animal-like
Examples of supergroup: Excavata are
euglenozoans
Examples of supergroup: Chromalveolata are
dinoflagellates, gold and brown algae, sporozoans
Examples of supergroup: Rhizaria are
foraminiferas
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
Excavata
_______ includes the dinoflagellates, which release the toxins that cause red tide in the oceans, and the parasitic sporozoans.
Chromalveolata
______ consists of foraminifera and radiolarians, which form external structures called tests made of calcium carbonate or silicon.
Rhizaria
_________ includes the photosynthetic red algae, green algae, and the land plants. The green algae are the ancestors of the modern plants.
Archaeplastids
________ consists of the ameoba-like organisms that move using cellular extensions called pseudopods.
Amoebozoans
________ consists of flagellated cells, such as choanoflagellates. This supergroup also contains the animals and fungi.
Opisthokonta (Unikonta)
________ make up phytoplankton, Red and green algae are eatable
Forams are useful in the field of paleontology
Dinoflagellates
Most fungi are ________
multicellular
Fungi are composed of microscopic filaments, called ________ that collect to form multicellular structures called ________.
hyphae; mycelium
A "__________" is a portion of the mycelium that has been dedicated to reproduction.
mushroom
Not all fungi _______ mushrooms.
produce
The mushroom you see in the supermarket is a ________.
reproductive structure
Fungi are often considered microbes because their "body" cannot usually be seen without a _______.
microscope
Fungi are all _______ organisms; they get their nutrients from organic material.
heterotrophic
Fungi are ________; they ________ their food, unlike animals that ingest their nutrients.
saprophytic; absorb
For many fungi, being a ____________ means that it absorbs dead or decaying material, such as logs or leaves in the forest.
saprobe (saprotroph)
In fungi, only the zygote is diploid, and all other stages of the life cycle are _______
haploid
During asexual reproduction, each mycelium produces _______, where _____(haploid) formation occurs.
sporangia; spore
______ 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.
Spores
Fungi have _______ instead of true sexes.
mating types
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.
combination hyphae
Animals and fungi are both in the _________ and are more closely related to each other than either are to plants.
supergroup Opisthokonta
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.
460 MYA
The first plants on land ____________ in symbiotic relationships, such as the mycorrhizae.
most likely brought fungi with them
Zygomycota
diverse group of fungi; includes bread molds; other species are parasites of insects
Ascomycota
commonly called the sac fungi; possess sac-like fruiting body, called an ascocarp; includes the yeasts and some forms of molds, morels and truffles.
Basidiomycota
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
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
energy cycle
All plants are __________________.
multicellular eukaryotes
Produce their own food by the process of _________
photosynthesis
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.
Archaeplastida supergroup
DNA evidence suggests that the plants evolved from a type of aquatic green algae called the _______ around 500 MYA.
charophytes
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.
vascular tissue
The dominant stage of a bryophyte is the ________, the green “leafy” part, which produces the gametes.
gametophyte
The sporophyte stage produces _________.
windborne spores
Pterophytes...
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
Lycophytes and ferns use _____ as the method of dispersing their spores for asexual reproduction.
wind
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
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.
reliant
Some relationships between some angiosperms and their pollinators have evolved to be ________.
very specific.
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 __________
supergroup Opisthokonts
The first animals most likely evolved from _________ similar to modern-day choanoflagellates
flagellated protist
The first animals appear in the fossil record around ______.
630 MYA.
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 ________
evolutionary tree
Animals are generally grouped by shared characteristics
Symmetry; Number of tissue layers; Absence/presence backbone; Type of body cavity
radial symmetry
symmetry around a central axis, as in a starfish or a tulip flower.
bilateral symmetry
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.
Sponges (Porifera)
_________________ 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.
Jellyfish (Cnidarians
________________ 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)
Flatworms (Platyhelminthes)
Acoelomate
Lack of an internal body cavity and therefore very few internal organs.
Pseudocoelomate
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.
Coclomate
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 (Mollusca)
Molluscs all have bodies composed of at least three distinct parts:
visceral mass ; a foot; a mantle
visceral mass:
the soft interior of the organism that contains internal organs
a foot:
a strong, muscular organ used for locomotion
a mantle:
a membranous or muscular covering that envelops the visceral mass
Gastropods
Organisms such as snails and coaches. Snails may have lungs and be terrestrial.
Cephalopods
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.
Bialves
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).
Annelids
Nematodes
round worms
Nematodes feed on __________
algae, fungi, microscopic animals, and dead organisms.
Which of the following is not a characteristic of a prokaryote?
nucleus
Prokaryotic cells can be classified by their nutritional mode. A chemoheterotroph is an organism that uses ______ for energy, similar to animals
organic materials
Which supergroup consists of protists that are photosynthetic and includes green and red algae?
Archaeplastida
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
Basidiomycota.
Which group of plants lack vascular tissue and include mosses, hornworts, and liverworts?
bryophytes
Invertebrate animals
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?
Cnidaria
Which group of vertebrates does not produce an amniotic egg?
amphibians
Both __________ and ______ must shed to grow
nematode; arthropods
are the most successful and diverse animals on the planet.
Arthropods
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
Crustaceans
Live marine and aquatic environments and have an exo skeleton that contains calcium carbonate and chitin. Examples are shrimp, crabs, and lobsters.
Insects
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.
Chelicerate
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
13,500 species
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.