Biology Exam 1 End of Chapter Qs
4. What is evolution?
"Evolution" is the heritable change over long periods of time and is usually defined as descent with modification.
7. What is taxonomy?
"Taxonomy" is the branch of biology that names & classifies species into groups of increasing breadth (size). Taxonomy uses phylogenies (i.e., evolutionary history trees) for the purpose of grouping of species based on common ancestry.
9. What is science? (NEVER-ENDING series of Qs)
"To know"; observation, identification, experimental investigation & theoretical explanation of natural phenomena.
12. What is the DNA/RNA/Protein world?
1. Information storage - DNA relieved RNA of its storage role so it could perform other functions. cells with both DNA and RNA would have an advantage over cells with just RNA. DNA also has stability and are less likely to spontaneously break like RNA. RNA made DNA through reverse transcription 2. Metabolism - proteins took over catalytic functions
11. What are the advantages of a dominant sporophyte life cycle?
A dominant sporocyte is diploid, is tougher, more complex, and may yield taller plants with more spores.
2. What is the eustele?
A stele typical of dicotyledonous plants that consists of vascular bundles of xylem and pholem strands with parenchymal cells between the bundles.
2. When did life started?
About 4 - 3.5 bya.
7. What is alternation of generations? Significance
Alteration of generations is a plant's ability to go from haploid to diploid during its lifetime. Its purpose is to go from sexual to asexual reproduction.
1. What are the similarities between Animals and Fungi?
Animals and fungi are both eukaryotes that can reproduce sexually and/or asexually. They are both heterotrophs with digestive enzymes that break down organic matter and store energy in the form of glucose. Animals and fungi are in the same supergroup, opisthokonta.
21. What is artificial selection and how it have affected angiosperm diversification?
Artificial selection has been employed by humans to mate and breed angiosperms that yield a specific quality, like corn with bigger kernels. This limits diversification because unfavorable traits become extinct and could even be hazardous for populations of angiosperms.
3. How does a fungus grow?
Asexually or sexually
3. What are the levels of organization?
Atoms: smallest unit of an element Molecules & Macromolecules: two or more atoms bonded together Cells: simplest & basic structural & functional unit of life Tissues: cells of the same kind that are associated to perform a particular function Organs: structures with two or more types of tissues that work together for a specialized purpose Organisms: an individual living thing Population: a group of organisms of the same species that occupy the same environment Community: an assemblage of populations of different species Ecosystem: the complex of interactions between communities & their physical environment Biosphere: all the ecosystems within our planet where living organisms exist
8. What are the three domains of life?
Bacteria: mostly unicellular prokaryotes that inhabit many diverse environments on Earth. Eukarya: unicellular/multicellular eukaryotes; complex cells with a nucleus (4 kingdoms: protista (unicellular), plantae (plants), fungi (mushrooms), and animalia (animals). Archaea: unicellular prokaryotes that often live in extreme environments, such as hot springs.
8. What is Ginkgo and its characteristics?
Bear heart shaped leaves and either bear ovules or pollen, although most trees are male.
2. What is the mycelium and hyphae? Forms, growth, structure, fruiting body
Body structure of a fungi= mycelium that is composed of individual microscopic, branched filaments known as hyphae Hyphae grow at the tip when osmotic pressure forces vessicles filled with the materials necessary for growth to the tip, where expansion grows There are two forms of hyphae: Aseptate (in which new nuclei are formed during cell division but not plasma membranes separating the daughter cells) and septae that reproduce to form cells that are joined via spores Fruiting bodies are extensions of the mycelium that grow from the food source and release spores for reproduction
3. What are the names of two extant species of organism similar to the early ancestors of land plants?
Bryocophytes, such as mosses and hornworths, are similar to the early ancestors of land plants.
8. What are the key characteristics of Bryophytes? Describe its three groups
Bryocphytes are the earliest type of land plant including mosses, hornworths, and liverworths. They are not vascular and reproduce via spores. They are small and must live in moist enviornments since their sperm are flagellated.
10. What are the ecological limitations of bryophytes?
Bryophytes have to live in moist areas. The sporophyte has a short lifetime and is dependent on the gametophyte. The sporophyte is much smaller and bryophytes lack vascular tissues.
11. What is chemical selection?
Chemical selection: occurs when a chemical within a mixture has special properties or advantages that cause it to increase in number relative to other chemicals in the mixture
17. What is the coevolution of flower and pollinator? Define the term and who was the first to describe it
Coevolution is the process by which two or more species of organisms influence each other's evolution evolutionary pathway. Pollinator is an animal that carries pollen between angiosperm flowers or cones of gymnosperms.
9. What are the conifers and their characteristics?
Conifers are evergreens with needle-like leaves. They have both pollen cones and ovule-bearing cones. They have resin inside and the seeds are either protected by a fleshy coat or wings. They also have tracheids that allow water to go up the tree and circular pits that prevent bubbles.
17. What is the continental drift? Its consequences, supercontinents
Continental drift is when Earth's continents move slowly over the underlying hot its mantle. Consequences
7. What are the Cycads and their characteristics?
Cycads are tropical, dioecious plants with collaroid roots (that contain cyanobacteria) and cone like structures that bear ovules or pollen (with flagellated sperm) and emit odors to attract pollinators.
10. What is discovery based science?
Discovery based science: Collection and analysis of data without the need for a preconceived hypothesis. Goal is to gather information.
15. Describe the process of double fertilization (draw the figure)
Double Fertilization: In angiosperms, the process in which two different fertilization events occur, producing both a zygote and the first cell of a nutritive endosperm
18. Mass extinctions, definition and number of events.
During a mass extinction, a large proportion of Earth's organisms become extinct in a relatively short period of geologic time 5 Mass Extinctions: Late Ordovician, Devonian, End of the Permian, Late Triassic, End of the Cretaceous
1. What is the age of our planet? Galaxy? Universe?
Earth is 4.55 billion years old. Galaxy//Solar System is 4.6 bya. Universe is 13.7 bya.
6. What are the key characteristics of embryophytes? Define cuticle, stomata, apical meristems.
Embryophytes are land plants who possess a cuticle made of cutin and wax to prevent dessication and predation. Embryophytes have stomata to allow gasses to move freely but not water. Embroyocytes have apical meristerms, which are regions of proliferation. Embryophytes are also capable of alteration of generations, meaning they can go from diploid to haploid.
5. First eukaryotes: The endosymbiotic theory, explain and evidence
Endosymbiotic theory: theory that the mitochondria and chloroplasts contained within modern animal and plant cells were once free living bacteria that were engulfed by another bacterial cell leading to the eukaryotic cell.
13. What was the first flower and where did flowers came from?
First flower= archaefructus sinensis and came from a gymnosperm in China during the cretacious period
13. What are fossils? How are they formed? Dated (half-life, etc)? Strata? Sedimentary rocks?
Fossils are preserved remains of past life on Earth Fossils are formed by Fossils can be dated using elemental isotopes in accompanying rock.
19. What are fruits and how are they dispersed?
Fruit is a structure that develops from flower organs. encloses seeds, and fosters seed dispersal in the environment. Fruits are the ovary of a plant that protects the seed within and encourages animals to spread the seeds
4. Differences between sexual and asexual reproduction among fungi?
Fungi grow asexually because it is easier to reproduce in an area that it is already well adapted to. Asexual spores, called..., grow at the end of hyphae. Fungi may reproduce sexually because genetic diversity allows them to charter new territories. Modern fungi have hyphae that when matched with another genetically compatible hyphae via secreted peptides, will grow together and fuse. Fruiting bodies release spores that fuse with haploid and genetically compatible mycelium.
7. What is the relevance of fungi to the Earth's ecosystems?
Fungi recycle organic material and break it down so it can be used. They are also predators and control populations.
4. What are the common features between green algae and plants?
Green algae are the closest living ancestors to plants. Both are photosynthetic and are capable of sexual reproduction. Both have plasmodesmata so cells can communicate with each other and are capable of cytokinesis, which is the division of the cytoplasm into 2 new daughter cells.
6. What are meristems?
Growing tissue at roots and shoots that are made of actively dividing cells.
3. What are the characteristics of Gymnosperms?
Gymnosperms are plants that produce seeds that are exposed rather than seeds enclosed in fruits... Don't produce seeds with a covering but have cones Woody plants Produce sperm
2. Characteristics of eons: Hadean, Archean and Proterozoic
Hadean Eon (Earth's Formation) Archean Eon (Early Oceans) Proterozoic Eon (1st Eukaryotes)
9. Describe the life cycle of mosses
Haploid male plants produce sperm in antheridia which travels to the an archegonia of female plants via water. Once inside the archegonia the egg is fertilized and become a sporophyte which depends on the gametophyte for nutrients. As it grows, the gametophyte is pushed upwards and covers a calyptra with teeth to hold the mature spores. These spores move with the wind when the teeth open and if they land in a suitable area, the cycle starts again.
11. What are the Gnetophytes and their characteristics?
Has broad leaves, like flowey plants Have prominent veins with wax Dioecious Have seeds within a fleshy tissue, called an aril, which implies that it may depend on animals to disperse seeds
12. What are defining characteristics of the Angiosperms?
Have fruits which encapsulate the seeds and flowers to attract pollenators Most prevalent Xylem with vessels wider than tracheids Have endosperm
6. What is horizontal gene transfer? Examples
Horizontal gene transfer: A process in which an organism incorporates genetic material from another organism w/o being the offspring of that organism. It's the transfer of genetic material from one organism to another that is NOT its offspring; not their direct ancestors and usually from different species. Getting genes from bacteria and plants, non-virulent species transformed into virulent species.
11. What is hypothesis testing?
Hypothesis testing: To formulate + test the validity of a hypothesis
13. What is a hypothesis, a theory and their differences? Examples (high probability to be true but NEVER 100%)
Hypothesis: a proposed explanation for a natural phenomenon. Based on previous observations or experiments. It must make predictions that can be shown to be correct/incorrect. Set a control (no treatment) & experimental (with treatment) groups. Results can support or reject a hypothesis, but a hypothesis is NEVER really proven. Theory: broad explanation of some aspect of the natural world that is substantiated by a large body of evidence. Allows us to make many predictions. As hypothesis a theory can never be proved true, but due to overwhelming evidence, is very likely to be true.
1. What are time divisions of the geological time: Eons, eras and periods?
Largest division: Eon spans hundreds to thousands of millions of years. Four eons: Hadean, Archaean, Proterozoic, & Phanerozoic. Two major eons: the Precambrian (1st three eons) eon and the Phanerozoic eon. Eons are made up of eras which are divisions that span time periods of tens to hundreds of millions of years Three major etas are the Paleozoic, Mesozoic, and Cenozoic. We are in the Cenozoic era.
1. How can you differentiate living and non-living things?
Living things are creatures that are alive and composed of tiny particles, i.e. cells. Simplest unit (cell); Use energy in any form; Interact with their environment. Maintain their organization; Grow & Develop; Reproduce & Use any form of information molecule. Change in form & become more complex over time; Related to other forms or share some common info. Specialized structures for specific functions; Specialized structures interact to give rise to complex functions or properties. Nonliving things refers to those objects or items that do not exhibit any sign of life.
What are the lycophytes
Lycophytes are seedless vascular plants that emerged in the carboniferous period.
22. Describe some differences between monocots and eudicots (two largest lineages of flowering plants)
Monocot embryo produces a single seed lead. Eudicots embryo possesses 2 seed leaves. The earliest leaves formed during the development of an angiosperm is called cotyledons. They can either be monocots, which have only on embryonic leaf, or eudicots, with more than one embryonic leaves. Monocots have long, narrow leaves with parallel veins, scattered vascular bundles, and floral parts in multiples of threes. Eudicots, such as dicots, have broad leaves with a network of veins, vascular bundles in a ring, and floral parts in multiple of 4 or 5.
11. What are heterospory and homospory?
Non-seeded plants (lycophytes and pteridophytes) are homosporic or they release only one type of spore. Seeded plants produce microspores and megaspores - heterospory Heterospory advantage - increases cross-fertilization
1. What is the significance of plants and the formation of soil?
Origin of land plants was essential for changing planet surface by fixing CO2 into organic materials (basis of agriculture).
7. What is Panspermia and the sea-vent hypothesis?
Panspermia Hypothesis: the inoculation of Earth by life carried on meteorites. Life evolved elsewhere then was transferred here. Deep Sea Vent Hypothesis: life may have begun at the interface where chemically rich fluids emerge from below the sea floor. Chemical energy is derived from the H2S and H coming out from the vent.
2. What are the key characteristics of plants?
Plants have the ability to go from haploid to diploid throughut their lifetimes (alteration of generations). They possess a cuticle made of cutin and wax that protect them from predators and prevent dessication,have embrous and spores that are well protected, and possess apical meristerms (which are localized regions of the plant body where most of the cell division occurs). Plants have stomata that allow gas exchange while preventing water loss.
1. What are the most important benefits that humans derive from plants?
Plants regulate the global temperature by emissions of CO2 and give us oxygen. They are a source of food not only for us but for other animals as well. Plants can provide medicine and can be toxic at the same time.
18. What are pollination syndromes? Examples.
Pollination Syndromes are the patterns of coevolved traits between specific types of pollinator. Pollination syndromes occur when only a specific vector can pollinate a flower (ex: bees cannot pollinate red plants)
16. What is pollination? Types of pollination.
Pollination is the process in which pollen grains are transported to an angiosperm flower or a gymnosperm cone primarily by means of wind or animal pollinators. Types of pollination includes abiotic + biotic. Abiotic includes wind + water; Biotic includes insects, birds, + mammals.
2. What are the 12 principles of Biology?
Principle 1: Cells are the simplest unit of life Principle 2: All organisms require energy from their environment Principle 3: All organisms interact with their environment Principle 4: All organisms maintain their internal organization Principle 5: All organisms change during their lifespan Principle 6: All organisms have genetic material composed of DNA Principle 7: All organisms evolve from one generation to the next Principle 8: All organisms at some point share a common ancestor Principle 9: Structure determines function Principle 10: Emergent properties in an organism always arise from the interaction of smaller individual components Principle 11: Biology is an experimental science (1) Observations of the natural world (2) Hypothesis driven research Principle 12: Biology affects how others (our society) understand the natural world
1. What are the Progymnosperms? What trait was inherited by Gymnospersm and Angiosperms?
Progymnosperms are an extinct group of plants having wood but not seeds, which evolved before the gymnosperms. Trait inherited was seeds. Progymnosperms are the precursors for gymnosperms and angiosperms. They were woody and bore spores.
9. What are protobionts and their characteristics? Examples
Protobionts are systems that are considered to have possibly been the precursors to prokaryotic cells. A protobiont is an aggregate of abiotically produced organic molecules surrounded by a membrane or a membrane-like structure. Protobionts exhibit some of the properties associated with life, including simple reproduction, metabolism and excitability, as well as the maintenance of an internal chemical environment different from that of their surroundings. It has been suggested that they are a key step in the origin of life on earth.
What are the pterophytes and their characteristics
Pterophytes are also seedless amd vascular and called ferns. They have fronds which hold sporangia on the underside and need water to reproduce.
12. What types of data are used by scientists?
Qualitative data (taking notes about something & what it is doing - observations/ descriptions) Quantitative data (basically measurements with a ruler/microscope which leads to trends)
10. Explain the RNA world? RNA versus DNA and Proteins.
RNA world: a hypothetical period on early Earth when both the information needed for life and the catalytic activity of living cells were contained solely in RNA molecules
5. What are the hypotheses on where and how organic molecules originated?
Reducing atmosphere: in the 1920s, AI Oparin and JBS Haldane hypothesized that the early atmosphere was a reducing environment: oxidation is prevented by removal or lack of oxygen. In 1953, Stanley Miller and Harold Urey used a chamber apparatus to simulate early atmosphere and bolts of lightning. Atmosphere rich in water vapor (H2O), hydrogen (H2), methane CH4, amonia (NH3). First attempt to apply experiments to understand origin of life. These experiments showed that prebiotic synthesis of life precursors, amino acids, sugars and nitrogenous bases was possible. Since the 1950s, ideas about early Earth atmosphere changed but most of these later experiments still support Miller's conclusions. Extraterrestrial source (Panspermia): Meteorites brought organic carbon to Earth which includes amino acids and nucleic acid bases. Opponents argue that most of these substances would be destroyed in the intense heating and collision before reaching early Earth surface. Even microorganisms might (very unlikely) travel in this meteorites. Deep-Sea vents: life formed in the early surfaces of... A kind of marine volcano (fissure in a planet's surface) were heated water emerges and Hydrogen Sulfide (H2S). Biologically important organic molecules (e.g., amino acids) may have been formed in the temperature gradient between extremely hot vent water and cold ocean water. The evidence is the complex biological communities that derive energy and organic compounds from these vents.
14. Why is Biology considered a social enterprise?
Scientists like to interact with other scientists. Different labs collaborate/debate.
20. What are secondary metabolites? Examples
Secondary Metabolites are molecules that are produced by secondary metabolism. Secondary metabolites are not necessary for plant survival but aid in pollination and include odors, colors, shapes, sizes, and sugar/protein rich substances that attract potential pollinators
12. What are some of the ecological advantages of seeds over spores?
Seeds provide some evolutionary advantages over spores. Seeds may remain dormant for days to years, until conditions are favorable for germination. Seeds have a large stored food supply. Seeds may be transported long distances by wind or animals.
14. Describe the parts of a flower and the types of flowers that exist
Septal= green outer protective covering Petals are colorful to attract pollinators Stamen posses the pollen Carpels/pistil contain the stigma (which receives pollen), style (long middle portion plant sperm must travel through), and the ovary which holds the ovum and will become the fruit) Complete flowers have all 4 layers Incomplete flowers lack some layer Perfect flowers have stamen and pistil and imperfect flowers have either or
8. Describe some of the negative effects of fungi for human and plant health
Since fungi are predators, they can cause disease or allergies in humans. Dimorphic fungi change from spores to yeast in humans and animals that inhale them, stick to lung tissue, and spread throughout the body. They also spoil our food. In plants, fungi may feed off of plant nutrients by forming haustoria.
13. Describe how fungi have benefited biotechnology, medicine and food industry
Some fungi are beneficial to humans because they can be a source of medicine as in penicillin and cylcosporine, which is used to prevent rejection in organ transplants. In biotechnology, fungi are used for their enzymes to break things down or to convert things in chemical reactions. Humans also use them for food production to make alcohol, bread, and yogurts.
10. What are the key innovations of the development of embryos by plants?
Specialized tissues: 1. Placental transfer cells are specialized to promote the movement of nutrients from gametophyte to embryo. 2. Have finger-like ingrowths of cell wall that increase surface area and facilitate transport of nutrients. Embryo enclosed in protective cover/seed coat which protects seed from physical, temperature-related, or water damage. The coat also ensures seed dormancy until conditions are right to germinate or sprout.
Describe the life cycle of ferns
Sperm and egg fertilize at the archegonium (halpoid sperm moves to halpoid egg via water) Sporophyte emerges from the archegonium and matures into sporangia Sporangia mature into spores via meiosis (haploid- diploid) Spore lands in a fertile area and become a hermaphroditic gametophyte that produces sperm in the anthridium and eggs in the archegonium
3. What are the 4 stages that gave rise to life? Their characteristics
Stage 1: Production of nucleotides and amino acids prior to the existence of cells. Stage 2: Polymerization of nucleotides and amino acids to form DNA, RNA and proteins. Stage 3: Polymers became enclosed in membranes. Stage 4: Polymers enclosed in membranes acquired cellular properties.
2. What is taxonomy?
Taxonomy is the branch of biology that names and classifies species into groups of increasing breadth using phylogenies.
4. What is the prebiotic stage and Earth's conditions at that time?
The prebiotic/abiotic synthesis stage has some conditions: little free O2 gas in the atmosphere, no living organisms around (no metabolizing or synthesizing) and accumulation of basic organic molecules in a prebiotic soup , Earth's conditions have been more conducive to spontaneous formation of organic compounds.
12. What are the characteristics of tracheophytes?
Tracheophytes are taller so they have less competition that bryophytes, have more efficient spore dispersal, and are less dependent on water.
5. What is vertical descent? Examples
Vertical gene descent: (MOST COMMON) examining a progression of changes in a series of ancestors the series is called lineage. Vertical evolution occurs in lineage. New species evolve from pre existing ones by the accumulation of mutations. Example is horse lineage.
6. Explain the Miller-Urey Experiment (Primordial Soup Theory)?
Water vapor from a flask of boiling water rose into another chamber containing hydrogen gas, methane, and ammonia. Miller inserted two electrodes that sent electrical discharges into the chamber to simulate lightning bolts. A condenser jacket cooled some of the gases from the chamber, causing droplets to form that fell into a trap. He observed the formation of hydrogen cyanide (HCN) and formaldehyde (CH2O), precursors of more complex organic molecules. These precursors combined to make larger molecules such as the amino acid glycine.
9. What is the white nose syndrome?
White nose syndrome is caused by a type of fungi that wiped out many bats.
4. What is plant wood? What is the vascular cambium?
Wood is a secondary plant tissue composed of numerous pipelike arrays of dead, empty, water-conducting cells whose walls are strengthened by an exceptionally tough secondary metabolite known as lignin. Vascular Cambium is a secondary meristematic tissue of plants the produces both wood and inner bark. Plant wood is an evolutionary structure that allows gymnosperms the ability to grow tall. Vascular cambium is the main growth tissue in stems and roots thay has a secondary xylem inwards and a secondary pholem towards the bark.
19. Are we in the midst of a mass extinction?
Yes, caused by human activities.
9. What is a plant embryo and describe its three main characteristics?
Young sporophytes that develop from zygotes. Emergence of embryos is critical innovation of land plants. 3 features: 1. Multicellularity and diploidy. 2. Zygotes will develop in embryos that retained maternal tissues for nutrition. 3. Better supply of nutrients enhances embryo survivorship.
14. Why is the fossil record incomplete?
a.) soft-bodied organisms don't preserve well b.) decomposition can interfere with fossilization c.) erosion events destroy fossils d.) not all fossils have been discovered
8. What is the relationship between clay, shallow oceans and polymerization?
origin of life ?
