Exam 1 Flashcards
What statement describes a cell?
The smallest unit that can be called life
Rank the following levels of biological organization from smallest to largest
Atom, molecule, organelle, cell, tissue, organ
A leaf is composed of several tissues organized to work together and is a(n) ______ of a plant.
Organ
What term refers to all parts of the planet that can support life?
Biosphere
What are the small chemical units that can combine to form molecules?
Atoms
What is the basic unit of life and consists of a membrane enclosing water, DNA, and other chemicals?
cells
Atoms can bond together to form
Molecules/Compounds
Compartments within cells that carry out specific functions are called
organelles
What is a structure consisting of tissues organized to interact and carry out specific functions?
an organ
______ are groups of specialized cells that function together.
Tissues
A level of biological organization called the ____. Includes all parts of Earth and its atmosphere where life can survive.
The biosphere
An organ _____ is composed of several organs that are connected and working together.
organ system
Particles that make up molecules are called
Atoms
What term refers to members of the same species living in the same place at the same time?
Population
What is a group of joined atoms, such as deoxyribonucleic acid (DNA)?
Molecule
Organisms that make their own food by obtaining energy and nutrients from nonliving sources are called
producers
What are membrane-bounded compartments within eukaryotic cells that carry out specialized functions?
organelles
What describes the state of internal constancy maintained by an organism?
Homeostasis
In the hierarchical organization of life, tissues are a collection of specialized ______ functioning in a coordinated way.
cells
What type of reproduction passes genetic information from only one parent to the offspring?
A-sexual
Multiple organs are linked together into _____
organ systems
Consider a species of frog that lives in many ponds throughout central California. A group of the frogs in one of the ponds, NOT including the other species of organisms living there, is an example of a(n)
population
in ____ reproduction, offspring are produced that contain a combination of genetic material from two parents.
sexual
A(n) ______ is an inherited characteristic or behavior which enables an individual to survive better than without the inherited characteristic.
Adaptation
Using a process called ______, living organisms maintain a state of internal constancy or equilibrium, such as a constant range of temperatures, nutrients, or water.
Homeostasis
List all of the characteristics of natural selection.
It favors adaptations to the current environment.
Genetic variability in organisms is required.
Production of runners, spores, and clones that bud from a parent are all examples of
A-sexual
In a new environment, what types of organisms will survive under the force of natural selection?
organisms with the highest reproductive success
Natural selection is a mechanism of ______ that selects for adaptations.
evolution
______ reproduction increases genetic diversity and is extremely common in animals.
sexual
what is evolution
changes in genetic makeup of a population over multiple generations
Flowers shaped for their pollinators, specific camouflaged color patterns of animals, and a beaver’s enormous front teeth for gnawing are all examples of
adaptation
What is taxonomy?
The science of naming and classifying organisms
Natural _____ is a mechanism of evolution in which certain individuals from a population exhibit enhanced reproductive success based on inherited characteristics.
selection
The traits of individuals that have higher reproductive success in a particular environment become more common within a population due to
Natural selection
In the scientific name Homo sapiens, the word Homo is the ______ of the organism and the word sapiens is the ______.
genus; species descriptor
True or false: Natural selection is a mechanism of evolution.
true
The change in genes of a population over multiple generations can also be referred to as
evolution
What is the science of naming and classifying organisms?
taxonymy
What is the basic unit of classification and is denoted by a unique two-part scientific name?
species
Biologists ask questions about
the natural world and living things
Natural selection is a mechanism of ______ that selects for adaptations.
evolution
Biologists begin a study by asking questions and
making observations
A tentative and testable explanation for an observation is called a ______ and is an essential early step of a scientific study.
hypothesis
If the results of a preliminary experiment support the hypothesis, then the scientists ____.
will not reject the hypothesis.
What uses evidence and experiments to test ideas and answer questions?
The scientific method
In the scientific method, a(n) ______ is an investigation carried out under controlled conditions to test a hypothesis.
experiment
In the scientific method, the first step is
observations and questions
In an experiment, the treatment manipulated by a scientist is called the ______ variable, and the response to the treatment measure by the scientist is called the ______ variable.
Independent, dependent
The data and results of an experiment may support or reject a(n)
Hypothesis
In an experiment, the response that an investigator measures and the treatment that an investigator manipulates are examples of
variables
List all of the qualities of a valid hypothesis.
It must be testable.
It can be rejected.
Hypotheses are often tested with an investigation called a(n)
experiment
The group in an experiment that is untreated and provides a basis for comparison is called the
control group
A ______ is an inert substance given to a portion of the experimental group to act as a control.
placebo
The variable of an experiment is
a changeable element of an experiment.
In science, a theory is a broad explanation for a natural phenomenon that is
widely accepted
Which of the following describes a control group?
a group that receives a placebo or no treatment
In a scientific experiment, a placebo is
an inert treatment given to the control group.
List all of the following that can be limitations to scientific studies.
biases of scientists
misinterpretations of results
reluctance to accept unexpected conclusions
all of the characteristics of variables in an experiment.
can be changed by the investigator
can be the response that is measured
Because science is ______, theories can change to accommodate new ideas and discoveries.
open to new information
One limitation of scientific experiments is that the results can be ______ when an incorrect explanation of the results is proposed.
Misinterpreted
Darwin and Wallace used the theory of ______ to hypothesize that a very long-tongued insect must exist that can pollinate flowers of the Angraecum sesquipedale on Madagascar.
evolution
List all of the past scientific conclusions that were later revised due to technological inventions and new data analysis methods.
The Earth is flat.
All organisms are either plants or animals.
The Earth is the center of the universe.
List all of the following that are characteristics of a scientific theory.
can be used to make predictions
encompass multiple hypotheses
supported by a large body of evidence
falsifiable
Both Darwin and Wallace predicted that because a species of orchid on Madagascar had unusually deep nectar tubes, there must be
an insect pollinator with a long tongue to reach the nectar.
A(n) ______ is an explanation for a natural phenomenon that has been well tested and ties together many hypotheses.
Theory
Both Darwin and Wallace predicted that because a species of orchid on Madagascar had unusually deep nectar tubes, there must be
an insect pollinator with a long tongue to reach the nectar.
A(n) ______ is an explanation for a natural phenomenon that has been well tested and ties together many hypotheses.
Theory
What process favors survival of specific individuals within a population based on inherited characteristics?
Natural selection
The change in genes of a population over multiple generations can also be referred to as
Evolution
what are organs made up of
tissue
List all of the statements that are true about asexual reproduction.
Genetic information comes from only one parent.
Offspring are virtually identical to each other.
Each type of organism is assigned a unique, two-part scientific name, which consists of the ______ of the organism.
genus and specific descriptor
In ecosystems, organisms that eat other organisms are called consumers, or
heterothrophs
What is the basic unit of classification and is denoted by a unique two-part scientific name?
a species
In ecosystems, organisms that eat other organisms are called consumers, or
heterothrophs
What is the basic unit of classification and is denoted by a unique two-part scientific name?
a species
Anything that takes up space is defined as
Matter
What is a pure substance that cannot be broken down by chemical means into other substances?
Element
What is a single unit of an element?
atom
If two atoms have the same atomic number, they are of the same
element
When two or more atoms are chemically joined they form a
molecule
Paper, water, computers, and you are all forms of ______ because each of these items takes up space.
matter
An electron ______ is an area around the nucleus of an atom where an electron is likely to be found.
orbital
what is an element
A pure chemical substance that cannot be further broken down
A type of chemical bond called a _____bond forms between atoms when one atom releases a valence electron to become a cation, and the other atom uses this electron to complete its own valence shell and becomes an anion.
Ionic
what is the smallest unit of an element that retains the characteristics of the element.
atom
what bond occurs within a molecule when two atoms in a molecule share electrons, such as carbon and hydrogen in the methane molecule pictured.
covalent
Atoms of the same element have the same number of
protons
What describes a hydrogen bond?
Atoms with opposite partial charges attract each other.
Molecules consist of two or more chemically linked ____ which are the smallest “pieces” or units of elements.
atoms
What substance regulates temperature, dissolves many chemicals, and has cohesive and adhesive properties?
water
In an atom, each individual electron orbital (not energy level) may contain up to _____ electrons.
two
What type of bond is formed from the attraction of two ions with opposite charges?
Ionic
What type of bond forms between opposite partial charges on adjacent molecules or within a large molecule?
hydrogen
List all of the reasons why water is essential to life
It plays a role in many chemical reactions.
It regulates temperature.
It dissolves a wide variety of substances.
The property of water that produces water’s surface tension is called _____ which is the tendency of water molecules to stick together.
cohesion
An electron orbital is ____
a region where an electron is likely to be located.
The fact that water is often the solvent in a solution demonstrates that water can
dissolve a variety of substances
Living organisms require a large temperature stimulus before the body temperature changes because the ______ bonds of water counteract molecular movement.
hydrogen
Cohesion is the tendency of water molecules to ____
stick together
Water expands as it freezes because the hydrogen bonds in ice
are stable and “lock” molecules into a more widely-space array.
why does salt dissolve in water
Polar water molecules surround Na+ and Cl- ions.
True or False, Atoms are created and destroyed in chemical reactions.
False
True or false: The presence of hydrogen bonds between adjacent water molecules increases the amount of energy required to raise water’s temperature.
true
A hydrogen ion (H+) has only one subatomic particle, a(n) ______.
proton
What type of bond involves two atoms sharing electrons which travel around both nuclei?
covalent
Buffer systems contain weak acids and bases and help solutions resist changes in
pH
Ice cubes float in a glass of water because ice is less ____ than liquid water
dense
What type of molecules are found in living things and contain both carbon and hydrogen?
organic
When the bonds of two or more molecules are broken and new ones formed, this is called
chemical Reaction
What ion dissolved in water is critical to the function of molecules and is called a proton?
H+
Polymers, such as carbohydrates, proteins, and nucleic acids, consist of small subunits called
monomers
What is an organic molecule with carbon, hydrogen, and oxygen in a 1:2:1 proportion?
carbohydrates
Pairs of weak acids and bases that resist change in pH are called
buffers
One subunit of an organic molecule is called a
monomer
What type of organic molecule is composed of monomers called amino acids?
protein
One subunit of an organic molecule is called a
monomer
Carbohydrates are macromolecules that include
sugars
A peptide bond is a type of ______ bond between amino acids.
covalent
Buffer systems contain weak acids and bases and help solutions resist changes in
pH
A protein is an organic molecule with diverse functions and is composed of monomers called
amino acids
The amino acid sequence of a polypeptide chain forms the ______ structure of a protein.
primary
The ______ structure of proteins involves the folding of the polypeptide chain into beta-sheets and alpha-helix coils due to hydrogen bonding.
secondary
A special type of covalent bond called a(n) ______ bond is formed between two amino acids through dehydration synthesis.
peptide
The ______ structure of a polypeptide is its overall shape and is formed through the interaction between R groups and water.
tertiary
Once a polypeptide or multiple polypeptides are folded into a functional shape, they are referred to as a
protein
Nucleotides are the monomers of polymers called
deoxyribonucleic
what includes triglycerides (fats), waxes, and steroids, are organic molecules that contain many nonpolar carbon-carbon and carbon-hydrogen bonds, making them hydrophobic.
lipids
Phospholipids that form cell membranes, steroids that act as vitamins and hormones, waxes that prevent water loss or water saturation, and triglycerides (fats) that act as energy reserves are all types of _______
lipids
Long chains of amino acids (100 or more) linked through dehydration synthesis form a molecule called a
polypeptide
all of the following that are components of lipids called triglycerides.
glycerol and fatty acids
What type of polymer is made up of many nucleotides?
nucleic acids
What group of organic molecules does not dissolve in water and does not consist of long chains of monomers?
lipids
Animal fats are ______ at room temperature and are called ______, while plant-derived lipids are ______ at room temperature and are called unsaturated fats.
solids, saturated fats, liquids
The ______ structure of proteins involves the folding of the polypeptide chain into beta-sheets and alpha-helix coils due to hydrogen bonding.
secondary
Animal fats are
saturated fats
list all of the following that are types of lipids.
waxes
triglycerides
phospholipids
steroids
a group of lipids, are more commonly known as fats and are composed of fatty acids bonded to a glycerol.
triglycerides
triglycerides such as bacon fat and butter contain _____ fatty acids, in which single bonds connect all the carbons; however, triglycerides such as olive oil and vegetable oil contain _____ fatty acids, in which there is at least one double bond between carbon atoms.
saturated, unsaturated
Many fungi, plants, bacteria, and animals produce toxic chemicals to _____
ward off potential competitors or predators.
What type of triglyceride contains the maximum number of hydrogens in its fatty acids because the carbons are all connected by single bonds?
saturated
List the three components of the cell theory devised in the mid-1800s.
All organisms are made of one or more cells.
All cells originate from preexisting cells.
The cell is the fundamental unit of all life.
What did Robert Hooke call the little units he observed when he viewed cork under lenses of glass?
cells
Select the three components of the cell theory devised in the mid-1800s.
All organisms are made of one or more cells.
All cells originate from preexisting cells.
The cell is the fundamental unit of all life.
The ______ microscope is ideal for viewing living cells that are between 200 nanometers and 1 millimeter in size.
The ______ microscope is ideal for viewing living cells that are between 200 nanometers and 1 millimeter in size.
All cells have a cell ______ that surrounds the cytoplasm and forms a boundary between the cell and its environment
membrane
Whether bacterium or blue whale, every organism is made of
cells
______ cells are the simplest forms of life and lack a nucleus.
prokaryotic
What English physicist first observed the outlines of cells when he looked at cork from an oak tree?
Robert Hooke
List all of the following that are present in bacterial cells.
ribosomes
DNA
cytoplasm
enzymes
What type of microscope passes light through a transparent or thinly sliced specimen to generate true-color views of cells?
light microscope
Key genetic sequences suggest that archaea are more closely related to members of domain ______ than they are to members of Domain Bacteria.
Eukarya
list all of the following that are present in both prokaryotic cells and eukaryotic cells.
ribosomes
RNA
cytoplasm
DNA
List all of the following that are true about prokaryotes.
simplest types of life
lack a nucleus
most ancient forms of life on Earth
All cells are surrounded by cell membranes, also called plasma membranes, that separate the cytoplasm from the
outside environment
List all of the following that differ between domains Bacteria and Archaea.
molecules that compose the cell membranes
evolutionary relationship to eukaryotes
chemical composition of flagella
In cell membranes, what part of a phospholipid molecule is oriented toward the outside of the bilayer?
phosphate head
In cell membranes, the phospholipids are arranged into a
phospholipid bilayer
The cell membrane can be described as a(n)
mosaic because many of the diverse components can move freely within the cell membrane.
fluid
What component of cell membranes functions in a diversity of roles, including recognition, transport, adhesion, and facilitating reactions?
proteins
The internal membranes of several organelles are interconnected and form the ______ system of a eukaryotic cell.
endomembrane
Why are ions and polar molecules unable to pass directly through a cell membrane?
The interior of the phospholipid bilayer is hydrophobic.
The internal membranes of several organelles are interconnected and form the ______ system of a eukaryotic cell.
endomembrane
The ______ produced in the nucleus enters the cytoplasm and binds to ribosomes, the sites of protein synthesis.
mRNA
The endoplasmic ______ is a network of membranes originating at the nuclear envelope and winding through the cell.
reticulum
The nucleolus is a dense spot in the nucleus where components of ______ are assembled.
ribosomes
Proteins to be secreted outside of a eukaryotic cell are formed at ribosomes on the surface of the ______ endoplasmic reticulum.
rough
What cell structure binds to mRNA coming from the nucleus and manufactures proteins?
ribosomes
Lipids, detoxifying enzymes, and membrane components are produced and stored in the _____ reticulum
smooth
What is a network of sacs and tubules extending off the nuclear envelope and is where proteins and lipids are produced?
endoplasmic reticulum
The ______ is a series of flattened sacs that sorts and packages materials into vesicles to be sent to the cell membrane.
Goli Apperatus
Lipids called ______, which include cholesterol, are membrane components that aid in membrane fluidity.
steroids
Organelles called lysosomes contain ______ that break down food particles, old organelles, and other cellular debris.
enzymes
What plant cell organelle can occupy up to 90% of the cell volume and can exert turgor pressure against the cell membrane when it acquires water?
central Vacuule
What eukaryotic organelle is shown in the picture and functions in the production of cellular energy by cellular respiration?
Mitochondrion
What organelle of the endomembrane system breaks down debris, food, and old cell parts with special dismantling enzymes?
lysosome
What plant organelle is shown in the image and contains photosynthetic pigments?
chloroplast
Plant cells have large central ______ where water, salts, and sugars are stored and where materials are broken down and recycled with enzymes similar to lysosomes in animal cells.
vaccule
What is the network of protein fibers and tubules inside the cell that provides support and aids in cell division and movement?
cutoskeleton
What is the function of mitochondria in eukaryotic cells?
Extract energy from foodq
In eukaryotic cells, what is the function of chloroplasts?
carry out photosynthesis
Cytoskeletal components called ______ are long, thin rods of actin protein that are used in muscle contractions, stretching and compression, and anchoring of cells.
microfilaments
List all of the following that describe tight junctions.
membrane proteins connect to actin in the cytoskeletons of adjacent cells
Join adjacent cells into sheets
create the “blood–brain barrier”
Short, numerous, hairlike structures that surround some cells like a fringe, are powered by microtubules, and have coordinated movements are called
cilia
Tunnels called ______ occur in the cell walls of two adjacent plant cells and allow the cells to communicate and exchange materials with each other.
plasmodesmata
Magnetosomes are adaptive because they allow bacteria to save energy as they move toward an optimal
O2 concentration
List all of the following that are present at the connection between normal cells of multicellular organisms.
ways that cells can communicate with each other
a way for cells to adhere to one another
In animal cells, cell junctions called ______ junctions form barriers between cells that prevent leaking of fluids and water-soluble molecules.
tight
Water, nutrients, hormones, and some organelles flow between adjacent plant cells through special channels in the cell wall called
plasmodesmata
As described in this chapter’s Investigating Life essay, some bacteria contain magnetosomes, which allow bacteria to
align with earths magnetic field
Define Metabolism
Collection of all chemical reactions in a cell
Anabolic Reaction-
Building reaction
Catabolic reaction-
tearing down reactions
facts about enzymes
contain proteins, have a 3D shape, very specific, and lowers activation energy, physical contact with substrate
When is an enzyme saturated?
when the enzyme activity is level
