Bio 123 Lecture Test 1 Chapter 1-5
Hydrogen bonds are weak bonds important in chemistry of life.
Slightly positive charged atoms in one polar molecule may be attracted to partial negative charge of an oxygen/ nitrogen atom in neighboring molecule.
What is a gene?
Something that is passed down from parent to offspring.
Polysaccharides are long chains of sugar units
Starch and glycogen are storage polysaccharides-cellulose is structural found in plant cell walls chitin is insect exoskeletin and fungi cell walls
A controlled experiment is one that...
Tests experimental and control groups in parallel
What is homeostasis?
The ability to maintain a balance.
What is the difference between a Eukaryotic and a Prokaryotic cell?
The first type of cell contains membrane enclosed organelles including a nucleus. The second type is a cell that lacks all organelles.
What is an allele?
Two are needed to control a trait.
Two monosaccharides are linked to form
a disaccharide
The chemistry of life is sensitive to acidic and basic conditions
A compound releasing H+ solution is an acid and accepts H+base. pH 0 is most acidic and 14 is most basic, 7 being neutral
Monosaccharide are simplest carbohyrates
A monosaccharide has a formula that is a multiple of CH2O and contains groups and carbonyl group
What is entropy?
A state of disorganization.
The distribution of electrons determines an atoms chemical properties.
An atom whose outer electron shell is not full tends to interact with other atoms and share, gain, or lose electrons resulting in chemical bonds.
Why are single celled amoebas and bacteria grouped into different domains?
Bacteria cells lack a membrane enclosed nucleus
Life molecular diversity is based on properties of carbon
Carbons ability to bond with four other atoms is basis for building large and diverse organic compounds hydrocarbons are carbon and hydrogen Isomers have some molecular formula but different structures
List four levels of organization in order common to all higher life
Cellular, Tissue, Organs, Organ system
Hydrogen bonds make liquid water cohesive
Cohesion creates surface tension and allows water to move from plant roots to leaves
Chemical reactions make and break chemical bonds
Composition of matter is changed as bonds are broken and formed to convert reactions to products
Organisms are composed of elements in combinations called ___________________. What makes up _____% of living matter?
Compounds, 96%, oxygen, carbon, hydrogen, and nitrogen
Selection pressures can act on which organisms chemical to change organism structure and function?
DNA
What best demonstrates the unity among all living organisms?
DNA is a common genetic code
Ionic bonds are attractions between ions of popular charge.
Electron gain and loss create charged atoms resulting in ions
The core idea that makes sense of all of biology is?
Evolution
Ice floats because it is less dense than liquid water
Floating ice protects lakes and oceans from freezing solid which protects aquatic life
Trace elements are common additives in what?
Food and drinks (fluoride, calcium ect.)
What is high fructose corn syrup and is it to blame for obesity?
HFCS-mixture of glucose and fructose derived from corn and added to food and drinks
Although radioactive isotopes can cause ______ are valuable in basic _____________ and _____________.
Harm, research and medicine
What is Darwins theory of natural selection?
He observed heritable variations and an overproduction of offspring which made him infer that natural selection is unequal reproductive success leads to evolution of adaptations in populations.
Waters hydrogen bonds moderate temperature
Heat is absorbed when hydrogen bonds break and released when hydrogen bonds form. Helps keep temp. steady. As most energenic molecules evaporate the surface cools.
A few chemical groups are key to functioning of biological molecules
Hydrophilic functional groups give organic molecules specific chemical properties
What distinguishes a hypothesis from a theory in science?
Hypotheses usually are narrow in scope. Theories have broad explanatory power.
Covalent bonds join atoms into molecules through electron sharing
In non polar covalent bonds, electrons are shared equally. In polar covalent bonds (water) electrons are pulled closer to more electronegative atoms
What is the purpose of DNA?
It carries genetic instructions.
What is a chromosome?
It carries out genetic information.
Fats are lipids that are mostly energy storage molecules
Lipids are diverse hydrophobic compounds composed largely of carbon and hydrogen fats(tryclycerudes) consist of glycerol linked to three fatty acids saturated is animal fats unsaturated is plant oils
What is the full hierarchy of organization from smallest to largest?
Molecule Organelle Cell Tissue Organ Organ system Organism Population Community Ecosystem Biosphere
What are five characteristics that are common to all life?
Order Reproduction Growth/Development Energy processing Regulation/Homeostasis Response to environment Evolutionary adaptation
A biologist studying interactions among protists in an ecosystem could not be working at which level in lifes hierarchy?
Organ Level
Provide four components necessary for natural selection to take place.
Organisms, DNA, Selection pressure, Artificial selection
Water is solvent of life
Polar or charges solutes dissolve when water moleciles surround them forming aqueous solutions
What domains can diversity of life be divided into?
Prokaryotes Bacteria Archaea Eukaryotes Protists Plantae Animalia
Atoms consist of what...?
Protons, Neutrons, Electrons, and a nucleus
