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157 terms

Biology Test #1

Chapters 1-5 and 7
STUDY
PLAY
Evolution
descent with modification; core theme of biology
Biology
study of life
Atom
smallest unit of an element, consists of protons and neutrons and electrons
Biological Organization
the hierarchy of life
biosphere - ecosystem - community - population - organism - all the way down to molecule
Emergent Properties
new properties that emerge with each step upward in the hierarchy of life
DNA
deoxyribonucleic acid; blueprint for building organisms
7 Properties of Life
a
Life is organized into 3 domains
bacteria, eukareya, archaea
Natural Selection
process in which organisms with inherited characteristics are more likely to live and reproduce
Two Approaches to the Process of Science
Discovery Science and Hypothesis-Based Science
Control in an experiement
factor that remains the same
Variable in an experiment
factor that changes
Goal of Science vs. Goal of Technology
Technology: apply scientific knowledge for specific purpose
Science: understand natural phenomena
Matter
anything that occupies space and has mass
Elements
substances that cannot be broken down to other substances by ordinal chemical means
Three most common elements
Carbon, Oxygen, Hydrogen
Trace Elements
elements that are essential, but only in minute quantities
Atomic Number
number of protons in each atom of a particular element
Atomic Mass
approximate total mass of an atom (sum of protons and neutrons)
Isotopes
variant form of atom; isotope of an atom has the same number of protons but different number of neutrons
Part of atom that influences chemical behavior
electrons
Ionic Bonds
when two ions with opposite charges attract each other and are held together
Covalent Bonds
two atoms share one or more pairs of outer-shell electrons
Nonpolar Covalent
covalent bond in which electrons are shared equally between two atoms with similar electronegativity
Polar Covalent
covalent bond between atoms that differ in electronegativity; shared electrons are pulled closer to the more electronegative atom, making it slightly negative and the other atom slightly positive
Hydrogen Bonds
type of weak chemical bond formed when partially positive hydrogen atom participating in polar covalent bond is attracted to negative atom participating in polar covalent bond
Solute
substance that is dissolved in a solution (ex. salt)
Solvent
dissolving agent in a solution (ex. water)
Solution
liquid consisting of homogenous mixture of two or more substances
Buffers
substances that minimize changes in pH
Organic Compound
carbon-based molecule
Polymer
long molecule consisting of building blocks (monomers) strung together
Four Organic Compounds
lipids, carbohydrates, nucleic acids, proteins
Enzyme
speeds up chemical reactions in a cell; missing a necessary enzyme could lead to lactose-intolerance
Main fuel of a cell
monosaccharide
Carbohydrate
consists of monosaccharides, disaccharides and monosaccharides
What breaks apart a polymer
hydrolysis through the process of adding water to break bonds in the cell
Main function of lipid
energy storage
Which monomers compose protein
amino acids (20)
What determines function of a protein
general shape
R. Hooke
examined a piece of bark and compared these structures to "little rooms," cells became the term
A. Leeuwenhoek
examined numerous subjects from human blood and sperm and pond water; first to observe and describe bacteria
Cell Theory
all living things are composed of cells and all cells come from other cells (discovered through microorgansims)
Magnification
increase in the apparent size of an object
Resolution
measure of the clarity of an image
Scanning Electron Microscope (SEM)
study detailed architecture of cell surfaces
Transmission Electron Microscope (TEM)
study details of internal cell structure
Mycoplasmas
smallest cell in human body
Muscle and Nerve Cells
largest cells in human body
Advantage of Cells being small
a
Prokaryotic Cell
cell lacking a membrane-enclosed nucleus; found in bacteria and archaea
Eukaryotic Cell
cell that has membrane-enclosed nucleus; all organisms except bacteria and archaea are eukaryotic
Antibiotics
target bacteria
Permeable
having pores or openings that permit liquids or gases to go through
Ribosomes
composed of ribosomal RNA and proteins, synthesize proteins according to directions from DNA
Proteins
made from free ribosomes, function within cytoplasm; inserted into membranes and packaged into organelles, exported from cell
Smooth Endoplasmic Reticulum (ER)
synthesizes lipids, processes toxins and stores and releases calcium ions; lacks attached ribosomes
Rough Endoplasmic Reticulum (ER)
manufactures membranes, attached ribosomes produce proteins
Golgi Apparatus
modify, store and ship products of the endoplasmic reticulum
Lysosomes
contains hydrolytic enzymes that digest cell's food and waste
Vacuoles
helps the plant cell grow by absorbing water and enlarging
Mitochondria
carry out cellular respiration and use energy in food to make ATP
Endosymbiosis
process by which mitochondria and chloroplasts of eukaryotic cells were formerly small prokaryotes that began living within larger cells
Cytoskeleton
network of protein fibers in cytoplasm of a eukaryotic cell
Cilia
short cellular appendage specialized for locomotion
Flagella
long cellular appendage specialized for locomotion
Nucleus
contains DNA that carries cells hereditary blueprint and directs its activities
Nucleolus
assembles ribosomes
Chloroplasts
present in plants, convert solar energy to chemical energy in sugars
Hydrogen Bonds
make water molecules cohesive, creating surface tension and allowing water to move
Compound
substance consisting of two or more different elements
Electron Shells
energy level representing distance of an electron from the nucleus of an atom
Electronegativity
an atoms attraction for shared electrons
Surface Tension
how difficult it is to break or stretch the surface of a liquid
Isomer
compounds with the same formula but different structures
Hydrophilic
water-loving and soluble in water
Monomer
building blocks of polymers
Dehydration Reaction
removes a molecule of water from monomers, creating polymers
Hydrolysis
cells break bonds between monomers by adding water to them
Monosaccharide
carbohydrate monomer, simplest carbohydrate, building block of di/polysaccharides
Disaccharide
two monosaccharides formed through dehydration reaction
Polysaccharide
polymers of monosaccharides linked together by dehydration reactions
Starch
storage polysaccharide in plants
Glycogen
animals store excess sugar in this glucose polysaccharide
Cellulose
most abundant organic compound on earth, helps to form walls of plant cells
Chitin
used by insects to build exoskeleton
Lipid
hydrophobic, includes fats, phospholipids, ans steroids
Phospholipid
major component of cell membranes
Amino Acids
organic molecule, serve as monomer of proteins
Cytoplasm
region between the nucleus and plasma membrane
Nucleoid
location of DNA of prokaryotic cell
Peroxisome
organelle that is involved in metabolic functions
Fluid Mosaic
description of membrane structure, cellular membrane has diverse proteins in small strands
Selective Permeability
membranes allow some substances to cross more easily than others
Passive Transport
diffusion of a substance across a biological membrane
Osmosis
diffusion of water across a selectively permeable membrane
Hypotonic
solution with a solute concentration lower than that of a cell
Hypertonic
solution with a higher solute concentration
Facilitated Diffusion
passage of a substance through a specific transport protein across a biological membrane down its concentration gradient
Active Transport
movement of a substance across a biological membrane against its concentration gradient, aided by transport proteins and requiring energy
Exocytosis
movement of materials out of the cytoplasm of a cell by the fusion of vesicles with the plasma membrane
Endocytosis
cellular uptake of molecules
Phagocytosis
cellular "eating"; a type of endocytosis when cell engulfs other cells
Pinocytosis
cellular "drinking"; type of endocytosis when cell takes in fluid
Receptor-meditated endocytosis
movement of specific molecules into a cell by inward budding of membranous vesicles
Cellular Respiration
harvesting of energy from food molecules
Endergonic Reactions
energy-requiring chemical reaction, which yields products with more potential energy than the reactants
Asexual Reproduction
creation of genetically identical offspring by a single parent
Chromosomes
structures that contain of an organism's DNA
Sexual Reproduction
creation of offspring by the fusion of two haploid cells, forming a diploid zygote
Cell Division
reproduction of cells
Binary Fission
prokaryotic reproduction by dividing in half (type of cell division)
Chromatin
combination of DNA and protein molecules
Sister Chromatids
one of the two identical parts of a duplicated chromosome in a eukaryotic cell
Centromere
region of duplicated chromosome where two sister chromatids join and where spindle microtubules attach during mitosis and meiosis
Cell Cycle
ordered sequence of events that extends from from time a eukaryotic cell is first formed to the division of a cell
Interphase
period in eukaryotic cell cycle when the cell is actually not dividing
Mitotic Phase
part of the cell cycle when the nucleus is divided, its chromosomes are distributed to the daughter nuclei, and cytoplasm divided, producing two daughter cells
Mitosis
division of a single cell nucleus into two genetically identical daughter nuclei
Cytokinesis
division of cytoplasm to form two separate daughter cells
Prophase
first stage of mitosis
Metaphase
third stage of mitosis
Anaphase
fourth stage of mitosis
Telophase
fifth and final stage of mitosis
Centrosomes
material in cytoplasm of a eukaryotic cell that gives rise to microtubules
Cleavage Furrow
first sign of cytokinesis during cell division in an animal cell; shallow groove in cell
Cell Plate
double membrane across the midline of a dividing plant cell, new cell wall forms during cytokinesis
Growth Factor
protein secreted by certain body cells that stimulates other cells to divide
Density-Dependent Inhibition
arrest of cell division
Anchorage Dependence
requirement that to divide, a cell must be attached to a solid surface
Tumor
abnormal mass of cells that forms within otherwise normal tissue
Benign Tumor
abnormal mass of cells that remains at its original site in the body
Malignant Tumor
abnormal tissue mass that can spread into neighboring tissue and to other parts of body
Metastasis
spread of cancer cells beyond their original state
Carcinomas
cancer that originates in the coverings of the body
Sarcoma
cancer of the supportive tissues, such as bone, cartilage, muscle
Leukemia
type of cancer of the blood-forming tissues, excessive production of white blood cells
Lymphoma
cancer of the tissues that form white blood cells
Homologous Chromosomes
two chromosomes that make up a matched pair in a diploid cell
Diploid Cell
organism sexually reproducing - cell containing two homologous sets of chromosomes, one from each parent (2n)
Sex Chromosomes
chromosome that determines sex of a baby
Autosome
chromosome not directly involved in determining sex of an organism
Gamete
sex cell; haploid sperm or egg cell
Haploid Cell
cell containing a single set of chromosomes (n)
Fertilization
union of the nucleus of a sperm cell with the nucleus of the egg cell
Zygote
fertilized egg, which is diploid, results from union of sperm and egg cells
Meiosis
in sexually reproducing organism, division of a single diploid nucleus into four haploid daughter nuclei
Tetrad
paired set of homologous chromosomes, each composed of two sister chromatids
Crossing Over
exchange of segments between chromatids of homologous chromosomes during synapsis in prophase I of meiosis
Genetic Recombiantion
production, by crossing over, of offspring with allele combinations different from those in the parents
Karyotype
display of micrographs of the metaphase chromosomes of a cell, arranged by size and centromere position
Down Syndrome
human genetic disorder resulting from presence of an extra chromosome 21 (trisomy 21)
Deletion
loss of one or more nucleotides from a gene by mutation
Duplication
repetition of part of a chromosome resulting from fusion with a fragment from homologous chromosome
Inversion
change in a chromosome resulting from reattachment of a chromosome fragment to the original chromosome, but in reverse direction
Translocation
during protein synthesis, movement of tRNA molecule from A site to P site on a ribosome
Somatic Cell
any cell in an organism except sex cells