PS 116 Test 3
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114 Terms
What is an ecosystem? What things does it include?
The community of all living and non-living things in an environment that are in a delicate balance. This includes: plants, animals, fungi, and bacteria.
What are the 6 characteristics of an ecosystem
Every ecosys consists of living and nonliving parts
Energy flows through it
Matter is recycled
Every organism occupies an ecological niche
Stable ecosys achieve a balance among populations
Ecosys are not permanent, but change over time
What is the difference between biotic and abiotic ecosystem components?
Abiotic consists of chemical and the physical environment, whereas biotic are living organisms and the ecological community
How does an ecosystem circulate matter and energy?
Through a food web (trophic levels)
What is an ecological niche?
Mode for survival; organisms compete for dominance/ survival of the fittest
What is the law of unintended consequences?
It is impossible to change one aspect of a complex system without affects the other parts, typically it results in “unintended consequences” and unpredictable ways
What is the equilibrium hypothesis in regard to ecosystems?
Ecosystems strive to maintain balance/ balance of animal populations and their food source
What contributed to the loss of the Aral Sea?
Irrigation projects from humans; it drained the water for crops and cotton.
What is the theory of island biogeography?
The biodiversity of an island is influenced by the balance between new, existing, and extinct species
Why doesn’t garbage in urban landfills quickly decompose?
Lack of oxygen in the landfill, bacteria and decomposers need the oxygen (methane gas is present)
Why is the ozone layer important to Earth’s inhabitants?
It absorbs most of the UV radiation from the sun
What are the atmospheric products of burning fossil fuels?
CO2, SO2, NO2, Carbon Monoxide
At roughly what altitude is the ozone layer?
30km / 19mi in the sky
What are CFCs? What things were they historically used in?
Chlorofluorocarbons
Aerosol and refrigerants
What is the greenhouse effect?
Traps heat and gasses on earth, absorbs and re-emits infrared radiation
Why is controlling the greenhouse effect so difficult?
Humans mess with stuff (too much fossil fuel burning)
What are some methods that captured carbon may be disposed of?
Captured carbon dioxide can be disposed of through methods such as geological storage, mineralization, enhanced oil recovery, biological sequestration, direct air capture, or utilized in various industrial processes.
Why do scientists think that global warming is occurring?
Increase in greenhouse gasses (CO2), through emissions of humans, thereby increasing earth’s temperature.
In the past, energy transitions in the US have taken roughly how many years to occur?
30-50 years
What are some ideas proposed to decrease emissions leading to global warming?
Green energy, carbon capture and storage, energy efficiency
What is the single thing that all life as we know it depends on?
Water
How does the scientific name of a living thing include both genus and species?
The first part of the binomial nomenclature is the genus, whereas the second part is species
How are Protists different from Fungi?
How protists differ from fungi is that protists are typically single celled and can either make their own food or absorb nutrients, whereas fungi are multicellular and only absorb nutrients.
The Archaea were discovered by using which research method?
They were discovered using molecular biology, specifically rRNA by Carl Woese and George Fox
What is the correct order (from highest to lowest), according to the Linnaean system of classification?
Kingdom, Phylum, Class, Order, Family, Genus, Species (King Phillip Came Over For Great Soup)
In the new view of biological classification, what are the three domains of life?
Bacteria, Archaea, Eukarya
What traits do all primates have in common?
Opposable thumbs, Forward Facing Eyes, Binocular Vision, Larger Brain, Nails (no claws), Various Teeth types, Parental Dependency, Dietary (omnivores).
What are some examples of Eukarya?
Plants, Protists, Fungi, Animals, Algae, Protozoa
How did Homo erectus compare to modern human beings on the Linnaean system?
They share the same Genus (Homo) but have a different species (sapien vs erectus) to show different stages in evolutionary history of the Genus Homo
What is the main difference between the Kingdoms of Monera and Protista?
Monera are single celled with no nucleus, whereas Protists are single celled (typically) with a nucleus
What traits are true of algae?
Photosynthetic, aquatic habitat, diverse forms, cell walls composed of cellulose, pigments, flagella, both sexual and a-sexual reproduction, producers
What is an example of a bryophyte?
Moss, non-vascular plants that lack true roots, stems and vascular tissues.
What is a vascular plant (and an example)?
A plant that has specialized tissues to transport water, nutrients and food throughout the plant.
A tree/ fern is considered a vascular plant
2 types of Vascular Plants
Seedless Vascular Plants (reproduce via spores)
Seed Vascular Plants
Gymnosperms (seeds not in fruits)
Angiosperms (seeds in fruits)
What processes do all plants have in common?
Photosynthesis, Transpiration (morning dew), Nutrient Absorption through roots, growth and development, both a-sexual and sexual reproduction, response to stimuli
Approximately how long have flowering plants been the dominant plant life on Earth?
65M years
What does “cold-blooded” mean in reference to animals?
They cannot regulate their own body temperature, so they rely on the external environment and various heat sources (ectothermic)
What is the most successful phylum in the animal kingdom (judging from the number of species and total biomass)?
Arthropoda (bugs, insects, crabs, arachnids, myriapods)
Are sponges plants or animals?
They are simple animals. They are filter feeders and lack complex structures (such as tissue, organs, and a nervous system).
What are the characteristics of a gymnosperm?
Seed producing plants that have naked seeds (not in a fruit). They have a cone-like structure (pinecone), needle-like leaves, vascular tissue, heterospory (microspores= male; megaspore=female), and typically rely on wind for pollination or their “cones” drop.
What part of a cell are made of fluid-like lipid bilayers?
Cell membranes
What types of organisms have a nucleus in their cells (and what do not)?
Eukaryotes have a nucleus, whereas prokaryotes do not
All protists are (prokaryotes/ eukaryotes/ bacteria/ plants).
Eukaryotes
Which structures do all cells have in common?
Cell membrane, cytoplasm, DNA (or RNA), Ribsomes
What is photosynthesis?
The conversion of sunlight to chemical potential energy
What function do chloroplasts serve for plants?
They enable photosynthesis, carbon fixation (“consuming” CO2 from the atmosphere to help it grow), Oxygen production, energy storage
Is photosynthesis an exothermic or an endothermic reaction?
Endothermic reaction
What are the functions of the cell membrane?
Selective permeability, cellular communication, cell adhesion, protection/ support, cell recognition (what is “friend” what is “threat”, ie immune system)
Which pair of organelles transfers energy in cells
Mitochondria and Chloroplasts
Are chloroplasts found in the cells of animals?
No, only plant cells
Which organelle gives the cell its shape?
Cytoskeleton
What is the present understanding regarding the origin of the nucleus?
Nucleus (was on its own as a foreign entity) passed through the double membrane originally and became a symbiotic relationship
What is ATP, and what is its purpose?
Adenosine Triphosphate: The storage molecule for energy, Forming ATP is endothermic
What is glycolysis?
The metabolic pathway the breaks down glucose into ATP and NADH, and serves as the initial step in cellular respiration (which provides energy to the cell)
What is an end-product of fermentation within Plants? Within Animals?
Plants: ethanol (alcohol) and CO2
Animals: Lactic Acid
How is meiosis similar to, and different from Mitosis?
Both refer to cell reproduction. Meiosis reduces the chromosomes by half and produce genetically diverse gametes (sex cells), whereas mitosis results in 2 identical daughter cells with the same amount of chromosomes as the parent cell
What element do all organic molecules contain?
Carbon atoms (as well as H, O, N, and S)
What attribute of the organic molecule controls the chemistry of life?
The structure of the organic molecule
What element do all amino acids contain?
C, H, O, N
What are the functions of proteins in living systems?
Catalysts, cellular signaling, immune system, storage, gene expression, cell adhesion, etc.
Carbohydrates are made from which three elements?
C, H, and O
What is the purpose of enzymes in chemical reactions in living things?
They serve as catalysts (reduces the required energy for a reaction to occur)
How many different amino acids are needed by humans to sustain life?
20 amino acids, 8 are essential
What are the chemical constituents of all proteins?
C, H, O, N, and S
What is the most complex shape of a protein?
The tertiary structure is the most complex shape of a protein
What is an essential amino acid?
It is an amino acid that cannot be produced by the human body and must be obtained from an outside source/ food source
What is the difference between high-quality proteins and low-quality proteins?
High-Quality: contains all essential amino acids and typically are found in animal-based sources
Low-Quality: they lack one or more essential amino acids and are found in plant-based sources
What is a monosaccharide (and an example)?
It is a simple form of a carbohydrate, consisting of one sugar molecule
An example would be glucose, energy source for organisms
What is a polysaccharide (and an example)?
It is a complex carbohydrate composed of multiple monosaccharides
An example would be glycogen, it serves as a storage form of glucose in animals and humans
What is a key difference between carbohydrates and proteins?
Their functions, carbohydrates serve as an energy source, whereas proteins have diverse roles such as structural support, enzyme catalysts, transport and more.
Which end of a phospholipid is hydrophilic?
The phosphate head
What is a lipid (and an example)?
A diverse group of hydrophobic molecules that includes fats, phospholipids, and steroids
Glycerol and fatty acids are examples
What is the difference between unsaturated and saturated fat (and give examples)?
Sat-Fats: no double bonds on their carbon atoms
Solid at room temp, butter is example
UnSat-Fats: One or more double bonds
Liquid at room temp, olive oil is example
Which vitamins are not retained in the human body?
Vitamin D and C
Which vitamins are fat soluble?
Vitamin A, B, E, K
Which chemical elements are not included in minerals?
Elements that are not included are C, H, N, and O.
What is the study of genetics?
The study of genes and heredity, how traits are passed from one generation to the next through DNA.
Who was Gregor Mendel, and what was his contribution to genetics?
A scientist who used pea plants to establish fundamental principles of heredity.
What is a gene?
A segment of DNA that contains the “instructions” for an organism. This determines traits and functions necessary for protein synthesis.
According to the Mendelian model, which generation and number of gene traits is indicated by the genetic distribution 9:3:3:1?
F2 Generation
What are the cellular functions of deoxyribonucleic acid (DNA)?
Stores genetic information, a “template”
What does the “double helix” of DNA refer to?
It refers to the structure of DNA
What are the parts of a nucleotide?
Phosphate group, sugar, and nitrogen base
What is the difference between DNA and RNA?
DNA is double helix structure, RNA is single-stranded and contains uracil as a nitrogen base instead of thymine
What is the genetic reason children so closely resemble their parents?
Inheritance, as it combines attributes from both parents
What are recessive and dominant genes?
Recessive genes are masked by dominant alleles, whereas dominant genes express their traits even if only one copy of it is present.
How is the likelihood of a trait being expressed linked to dominant and recessive genes?
Dominant genes are more likely to be expressed in the presence of 1 or 2 copies, whereas recessive genes require 2 copies to be expressed
What is the difference between ribose and deoxyribose?
Ribose has hydrox (presence of oxygen) on the second carbon, DNA lacks oxygen resulting in 2 hydrogen
How many base pairs code all genetic information on DNA?
~3B base pairs
What is DNA transcription?
A complementary RNA molecule is synthesized from DNA, which “reads” a specific gene and synthesizes a mRNA molecule that carries the genetic information to where it is needed
What is a codon?
A 3 nucleotide sequence mRNA that codes for a specific amino acid or signals a “stop” in protein synthesis
Where does protein synthesis in a cell actually take place?
Takes place in the ribosomes, which is in the cytoplasm on the endoplasmic reticulum
What is the central dogma of molecular biology?
DNA transcribed to RNA and RNA translates to a protein
How are genetic mutations caused?
Errors in DNA replication, exposure to radiation or chemicals, external factors such as environmental influences
What is the difference between mRNA and rRNA?
mRNA carries genetic information from DNA to the ribosomes, rRNA is a structural component of ribosomes (which assembles amino acids into proteins during translation)
What is epigenetics?
“Outside the genes” studies ways to influence inheritance that don’t directly involve genes (ie smoking and drinking)
What is the underlying principle of genetic engineering?
The manipulation of an organism’s DNA to introduce, modify, or delete specific genetic traits.
How was insulin for human use historically produced?
From the pancreas of cows and pigs
How is most insulin for human use currently produced?
Genetically modified yeast and bacteria
What is the most common application of genetic engineering at this time?
Medicine