Exam 3 Flashcards
Homology is established though similarities in developmental pathways, specifically _________.
embryos
What did German biologist Ernst Haeckel tie similarities in developmental pathways to?
Evolutionary Change
What does “Ontegeny Recapitulates Phylogeny” Mean?
development of an organism (ontogeny) expresses all the intermediate forms of its ancestors throughout evolution (phylogeny)
What are genes that control where, when, and how other genes are expressed?
Master Genes
Homeotic Genes are type of _________. What do they regulate?
- Master Genes
- Regulate expression of body parts by regulating where, when, and how genes downstream will be expressed.
HOX genes are a type of __________. What do they do?
- Master Genes
- Set up Anterior-Posterior and Dorsal-Ventral Axes
HOX genes are arranged in what way on chromosomes?
Co-linear
What is evidence for the importance of HOX genes?
They have been conserved over time
What genes spur eye development?
PAX genes
While the same homeotic genes can occur in several species, variants in the regulatory genes can still arise through ________ ________.
Random Mutation
What acts to shape the effects of mutations in homeotic genes in terms o fitness and frequency within the population?
Selection
What is the most important source of new genes?
Gene duplication
What is the term that means more copies of all genes?
Polyploidy
What causes unequal crossing over so that one chromosome gets extra copies of a gene?
Misalignment in meiosis
What are three consequences of gene duplication?
- New copy may not have the same functional constraints as the ancestor copy
- Mutations may accumulate in the new copy with fewer consequences
- Mutations may allow the new copy to perform new functions
What are gene families and what are two examples?
- Clusters of genes similar in structure and sequence
- HOX genes, Globin Genes
The Globin Gene family includes _________, which are non-functional as globin genes and are usually not transcribed.
pseudogenes
Selection acts ________ on each gene in a gene family.
Independently
How long ago did earth form?
3.6 billion years ago
What is the period called from the origin of the solar system to about 3850 ma and what are two characteristics?
- The Hadean
- No fossil record
- Almost no geological record
What are four key events from the Hadean period?
- Differentiation of earth into crust, mantle and core
- origin of the atmosphere
- condensation of water vapor
- Origin of continental crust
What are three attributes of life?
- Autonomous replication
- Critical level of complexity
- Ability to evolve via natural selection
What are requirements for life?
- An energy source
- Basic chemicals
- An external environment that sustains life
In what era and eon was the origin of life?
Eon: Archean
Era: Eoarchaen
What did early life most likely consist of?
prokaryotic bacteria-like organisms
Archaea are _______.
Extremophiles
During what eon was the origin of eukaryotes?
Proterozoic
What resulted after the origin of eukaryotes?
Rapid diversifiction of soft-bodied multicellular animals and green algae
What theory states that eukaryotic cells evolved when aerobic bacteria either infected or were engulfed by a larger host cell and later established a symbiotic relationship?
Serial Endosymbiosis Theory
Mitochondria are thought to be derived from _____ ______, while chloroplasts are thought to be derived from ________. This is part of what theory?
- Purple bacteria
- Cyanobacteria
- Endosymbiotic theory
What are two pieces of evidence for chloroplasts and mitochondria as endosymbiotic organelles?
- Circular genomes in chloroplasts, mitochondria, and bacteria
- Mitochondria have cell membranes similar to prokaryotes
In the progression toward multicellularity, single-celled eukaryotes evolved into what?
Colonial eukaryotes
What is an example of groupings of individual cells? What enables cells to stick together?
- sponges
- collagen
In the progression toward multicellularity, differentiated multicellular eukaryotes evolved from what?
-Colonial eukaryotes
What are three challenges of multicellularity?
- The need for support, rigity, increase
- Reproduction becomes more difficult
- Suface-to-volume ratio decreases as size increases
What is the opportunity of multicellularity?
-Cellular and tissue specialization and greater complexity becomes possible
What is the Cambrian Explosion?
-Sudden appearance of diverse forms in the fossil record
Fossils of many phyla first appeared in the _______ _______.
Cambrian Explosion
What happened by the end of the Cambrian Explosion?
All major phyla were present
What is the intrinsic explanation for the Cambrian Explosion? Give a possible explanantion
- Something about animals changed
- Hox and Hox-like genes were duplicated in organisms with bilateral symmetry, causing increased complexity
What is the extrinsic explanation for the Cambrian Explosion? Give three possible explanations.
Something about the environment changed
- Ancient atmosphere had insufficient Oxygen to allow the evolution of large animals with active lifestyles
- A mass extinction allowed new forms
- Ecosystem reached a tipping point in complexity resulting in widespread co-evolution
What are two explanations for where life came from?
- Abiogenesis (life originated from abiotic precursors that existed on earth)
- Panspermia (life originated from abiotic or biotic precursors that arrived from extraterrestrial sources)
The physicist John Desmond Bernal suggested three clearly defined stages that could be recognized in explaining life’s origins. What are they?
- The origin of biological monomers
- The origin of biological polymers
- evolution from molecules to cell
What did the Miller-Urey Experiment do?
Synthesized organic compounds from inorganic precursors
What is the RNA World hypothesis?
Early life was based on RNA. This was short-lived once oxygen became abundant and DNA-based life became more prevalent.
What are the three domains?
- Bacteria
- Archaea
- Eukarya
What are the four kingdoms in the Eukarya Domain?
- Protists
- Fungi
- Plants
- Animals
What is the heiarchy of domains and kingdoms?
Domains = highest Kingdom= one lower than domain
Bacteria and Archaea are types of what?
Prokaryotes
At least how old are prokaryotes?
3.6 billion years old
What fossils consist of layers of bacterial mats and can still be found today?
- stromatolites
- These are a type of prokaryote
What originally produced an oxygen atmosphere?
Early photosynthetic prokaryotes
Which is there more of: prokaryotes or eukaryotes?
Prokaryotes
What cause about half of all human disease?
prokaryotes
What are three properties of bacteria?
- All share a common ancestor
- Single-celled prokaryotes
- Asexual reproduction
What are the three basic shapes of bacteria? Give an example for each shape.
- Coccus (round)
- Bacillus (rod)
- Spirillum (spiral)
How are bacteria classified into their two major groups? What are the two groups based on?
- Gram Stain
- Based on celll wall structure
How do humans encourage antibiotic resistance?
By not continuing to take antibiotics as prescribed until all antibiotics are used. This develops antibiotic-resistant bacteria.
How can bacteria be beneficial?
You have a normal amount of bacteria in your body that is good for you. Probiotic therapy is used to swamp your body with helpful bacteria to outnumber the harmful bacteria.
What is one of the most important bacterial discoveries?
Thermus Aquaticus, because it is used in polymerase chain reaction
How are archaea similar and different to bacteria?
Similar: appearance, prokaryotes, single-celled
Different: DNA, cell wall chemical composition, flagella
What organisms are known as extremophiles and why?
- Archaea
- Found almost everywhere
What are four properties of eukarya?
- Nucleus
- Cytoskeleton
- Mitochondira
- Chimeric genome
What does it mean that eukarya have a chimeric genome?
They have some genes from bacteria, some from archaea, and some unique to eukarya
How to genomes grow over the course of evolution?
New genes arise through the duplication of existing genes, but diverge in function
What is the constraint on single cells? Why is this a constraint?
- Cells must stay small
- They must maintain their surface area to volume ratio to take in and release water, nutrients, and wastes
What are cells that are connected by intercellular junctions and function as a unit called?
Tissues
What do junctions between tissue cells do?
Hold tissues together and allow for communication
Coloniality has evolved _________ in many prokaryote and protist lineages
Independently
Multicellularity has evolved __________ in several eukaryote groups
Independently
What one feature do all protists share?
They are eukaryotes
What is the most diverse group of organisms?
Protists
True or false: Protists can be single-celled and multicellular
True
True or false: Protists have a small range of body plans
False
What are the three traditional groupings of protists? Give an example of each.
- Animal-like (Protozoans)
- Plant-like (algae)
- Fungus-like (molds)
How do animal-like, plant-like, and fungus-like protists get their energy?
- Animal and fungus-like = chemeotrophs
- plant-like = phototrophs
Most animal-like protists are _________. What do they do?
- unicellular
- pass diseases
How are fungi different from plants?
- lack chloroplasts
- do not photosynthesize
- some are unicellular (yeast)
- heterotrophic
Fungi are more closely related to animals than plants. What similarities do fungi and animals share?
- cell walls contain chitin as in some animals, and not cellulose as in plants
- carbohydrates are stored as glycogen as in animals, and not starch, as in plants
How do fungi feed?
- Heterotrphic
- Absorption
- Most are decomposers, some are parasitic, and some are symbiotic
What is the structure of the fungi body like? Why?
- Like a network of thin filaments
1. provides a large surface area for absorbing nutrients
2. penetrates the fungus’s food source
3. Secretes enzymes that break down molecules
4. Absorb resulting nutrients
What are tiny filaments of fungi that form a network underground or “body” above?
-Hyphae
What are mycelium?
The interwoven network of hyphae underground
What is the release of spores?
Sporulation
What are primitive fungi that produce swimming spores that have flagella? What are they known for?
Chytrids
-They infect frogs and are parasitic and kill the frogs
Mycorrihizal fungi form symbiotic relationships with plant roots. Why? What do mycorrihizal form from?
- Helps the plant better absorb nutrients
- Fungus gets carbohydrates from the plant
- form from glomeromycota
What are they fungi zygomycota known for?
The molds that grow on food
Slime molds are _______ while other molds are_______.
- protists
- fungi
What is the fungus Ascomycota known for? Why are they important?
Yeast
- Important economically for food such as bread and wine
- Important Gastronomically for edible mushrooms
- Important medically for penicillium, the source for penicillin
A ______ is the result of a relationship between a fungus and photosynthesizer such as green algae or cyanobacteria.
lichen
What is the domain and kingdom of plants?
Domain: Eukarya
Kingdom: Plantae
What are five properties of plants?
- Multicellular eukaryotes
- Well-Developed tissues
- Mostly terrestrial and sessile
- Exhibit embryo protection
- Photoautotrophic
What were the earliest plants like?
Fossil Spores
What features did plants evolve to adapt to life on land?
- resist drying out
- absorb nutrients
- stand upright without outside support
- reproduction not dependent on water
What feature distinguishes plants from green algae?
Embryo protection- all plants nourish a multicellular embryo in the body of a female plant
What is another name for non-vascular plants?
bryophytes
What are two properties of bryophytes? give an example of one.
- simplest, primitive, earliest plants
- Lack roots and vascular tissue
- mosses
What are three qualities of earliest plants?
- have cuticle
- no roots or true leaves
- small
What is the vascular tissue made of?
xylem and phloem
True or false: Vascular plants have seeds.
False, they are seedless
What group is the most diverse seedless vascular plant?
pterophytes (Fern)
Seeldess Vascular plants were the first to do what?
- evolve vascular tissue
- use spores for reproduction
Are vascular plants larger or smaller than bryophytes?
Larger
What is the term for an embryo and stored nutrients within a protective coat?
seed
Vascular seed plants use seeds for dispersal rather than _______.
Spores
What is an example of a vascular seed plant?
Conifers
Vascular plants with naked seeds are called _________.
Gymnosperms (Gymn = naked)
What are reproductive structures that attract pollinators and develop into fruit?
Flowers
Flowers distinguish the ________ from the _______ .
angiosperms
gymnosperms
What is a flower?
A modified shoot (stem and leaves) with up to four whorls of modified leaves encircling them
What two whorls are sterile?
Sepals and petals
What two whorls are reproductive?
Stamens and carpals
In angiosperms, the ovule is buried in the ______ of a flower, so it is not naked.
tissue
What are the outermost, green, leaf-like parts that protect the growing bud?
sepals
What are flower parts just inside the sepals that are often colorful to attract pollinators?
Petals
What makes up the stamen?
Filament and anther
What makes up the carpal?
Stigma, style, and ovary
What two things prevent self-fertilization in plants?
- The stamens and the carpals mature at different times
2. Many angiosperms have self-incompatibility
Why are angiosperms more successful than gymnosperms?
- angiosperms have short reproductive life cycles that allow them to evolve more rapidly, where as gymnosperms have slow life cycles
- Angiosperms advertise
How have plants and pollinators undergone coevolution?
- Plants have become more effective at attracting specific pollinators
- Pollinators have become more effective at exploiting specific plant resources
Fruits develop from _______ _______.
Pollinated flowers
After a flower has been pollinated, the embryo becomes a _______.
Seed
What are three properties of animal-dispersed seeds and fruits?
- Colorful and Conspicuous
- Taste good
- Usually good for animals
___________ are the first and only plants to have flowers and produce fruit.
Angiosperms
What is the most diverse plant group?
Angiosperms
What domain and kingdom are animals in?
Domain: Eukarya
Kingdom: animaia
What are three properties of animals?
- Muticellular
- Eat other organisms (heterotrophic)
- Move
How many animal phyla are there?
35
What are the categories to distinguish groups of plants?
- nonvascular plants vs. vascular seedless plants
- vascular seedless plants vs. gymnosperms
- gymnosperms vs. angiosperms
What are the categories to distinguish groups of animals?
- True tissues vs. no true tissues
- Tissued animals: bilateral vs. radial symmetry
- Blastopore fate: Deuterostome vs. protostome
- Protostome development: lophotrochozoans vs. Ecdysozoa
What is the term for no true tissues?
parazoa
What is the term for multiple tissue layers? what is the term for two? what is the term for three?
- Eumetazoa
- Diplobast
- Triploblast
Sponges have no ________ and no _______.
- tissues
- symmetry
What do sponges used to move water in and out?
Choanocytes
What is the term for when multiple planes divide the organism into mirror images?
Radial Symmetry
What is bilateral symmetry?
One plane divides the organism into mirror images
True or false: Eumetazoans are divided into two groups based on adult symmetry
False, they are divided based on larval symmetry
What type of tissues and symmetry do cnidaria have?
- diploblast
- radial symmetry
What are cnidocytes?
Stinging cells in cnidaria
Jellyfish and corals are examples of what?
Cnidarians
What is the relationship between coral and algae? What is coral bleaching and what causes it?
- symbiotic relationship: corals get their nutrition from algae that live with them
- coral bleaching occurs due to rises in sea temperature and is when corals expel their algae
What is the blastopore fate of deuterostomes and protostomes?
Deuterostome: anus
Protostome: Mouth
What two groups are protostomes further divided into?
- Lophotrocozoans
- Ecdysozoa
What are properties of lophotrocozoans?
- Hollow feeding appendage
- Use cilia for motility
What are properties of ecdysozoa?
-Have exoskeleton that must be shed in order to grow
What three phyla are lophotrocozoans?
- Annelids
- Platyhemithes
- Molluscs
What kind of tissues do Mollusca have? What kind of symmetry do they have? What is their blastopore fate?
- triploblastic
- Bilateral
- Protostomes
What phylum do Gastropoda fall under? What is a characteristic property of them? Give an example.
- Mollusca
- stomach foot: foot sits ventral to the rest of the body
- Snails
What phylum do Bivalvia fall under? What is a characteristic property of them? Give and example.
- Mollusca
- Large shell covers entire body so muscular foot is hidden in the shell
- clam
What phylum do Cephaopoda fall under? what is a characteristic property of them? Give an example.
- Mollusca
- Muscular food sticks out of head portion
- Squids
Annelids have a ________ body.
Segmented
What kind of tissues and symmetry do annelida have? What is their blastopore fate? Give an example.
- Bilateral symmetry
- Triploblastic
- protostomes
- earth worm
What kind of tissues, symmetry, and blastopore fate do platyhelminthes have? Give an example?
- Triploblastic
- Bilateral
- Protostomes
- Tapeworms
What is the term for shedding of the exoskeleton and replacing it with a larger one at regular intervals?
-Molting
Which two phyla undergo molting?
Arthropoda and Nematoda
What kind of symmetry, tissues, and blastopore fate do Nematodes have? Give an example.
- Bilateral
- Triploblastic
- Protostome
- Round Worm
What kind of symmetry, tissues, and blastopore fate do Arthropoda have? Give an example.
- Bilateral
- Triploblastic
- Protostomes
- Insects
Which is the most successful phylum in terms of overall species?
-Arthropoda
Which group of arthropods has the most species/ is the most diverse?
Insects
Insects undergo ______, in which they mature to their adult form
Metamorphosis
Which phyla are deuterstomes?
Chordata and echinodermata
Which phyla is described as bilateral symmetry, triploblastic, and deuterostomes? Give an example.
- Echinodermata
- starfish
What kind of symmetry, tissues, and blastopore fate do chordates have?
- Bilateral
- Triploblastic
- Deuterstome
Besides chordata, which is the only phylum with diploblastic tissues?
Cnidaria
What four things are characteristic to all chordates?
- Dorsal Hollow Nerve Chord
- Pharyngeal gill Slits
- Notochord
- Post-anal tail
What group of chordates are called “water bears” and can survive extreme conditions?
Tardigrada
The majority of vertebrates are _____.
Fish
What is the study of the interactions of organisms with their environment?
Ecology
What four things does Ecology look at?
- Individual
- Population
- Community
- Ecosystem, both biotic and abiotic factors
Populations interact to form _______.
Communities
What is predation?
When one organism feeds on another
Predation forms a strong _______ _______ on prey, causing them to do what?
- Selective pressure
- Develop camoflage, warning coloration, or other defenses
Give an example of organisms that use mimicry as a defense.
Monarch butterflies has toxic substances and is colored to warn predators of this. The Viceroy butterfly has adapted to look like the monarch to make predators think it is also toxic.
Give an example of mechanical defenses in organisms.
Spikes on a cactus, turtle’s shell
How do animals use chemical defenses to fight predation?
They synthesize toxin or accumulate it from the food they eat
What is symbiosis and what are the three forms of it?
- Close interactions between species
1. parasitism
2. mutualism
3. commensalism
What is the term that is used when interactions between species are strong?
Coevolution
What is a non-mutual symbiotic relationship between species, where one species, the parasite, benefits at the expense of the other, the host?
Parasitism
Interactions in which one species benefits and the other is neither benefited or harmed is ?
Commensalism
Coevolution is selection driven by interactions between ________. They are engaged in a reciprocal adaptive response.
-Species
How is coevolution different than every other concept we have learned in class?
-It is about interactions between species, not populations of the same species
In coevolution, each participant in the relationship undergoes natural selection. What is the highest fitness associated with?
genotypes that address the partnership
How does coevolution happen?
- Mutualism
- Arms race (predator/prey)
- Co-Speciation (host/parasite)
Mutualism is a form of ______ where both partners _______.
- symbiosis
- benefit
To be coevolution, the predator-prey relationship must be the ___________ selective force, and there must be _________ in the response.
- primary
- reciprocity
What is cospeciation?
-Host and parasite lineages diverge at the same time
What is a gradual change in species composition over time?
Succession
What is primary and secondary succession?
- Primary: no soil exists
- Secondary: a community has been changed, but soil remains
______ ______ recycle the atoms that make up every object in an ecosystem.
Nutrient cycles
What is the trophic level of the food chain?
-Relative to the energy source
Under ideal conditions, what kind of population growth occurs?
Exponential growth, where a population grows at a rate proportional to its size
What two things limit population growth?
- Environmental resistance (limited resources)
2. Carrying capacity
Population grows and then stops when it approaches the _______ _______ .
Carrying Capacity
What kind of population growth accounts for environmental resistance?
Logistic Growth
