Midterm Flashcards
In an ecosystem, energy
typically flows from producers through a series of consumers.
You notice that over the past month, many students on campus have started wearing a new style of school sweatshirt. You think to yourself that perhaps the bookstore has recently started selling this new sweatshirt style. This is an example of
a hypothesis.
Organisms belonging to the kingdom Plantae
are photosynthetic.
Which of the following statements about ecosystems is false?
Chemical nutrients cycle within an ecosystem.
Plants and other photosynthetic organisms are producers in ecosystems.
In the process of energy conversions within an ecosystem, some energy is converted to heat.
Bacteria and fungi recycle energy within an ecosystem.
Bacteria and fungi recycle energy within an ecosystem.
Kingdom Fungi includes species
that obtain food by decomposing dead organisms and absorbing the nutrients.
Members of the kingdom Animalia
can obtain their food by eating other organisms.
Which of the following statements about the domain Bacteria is true?
Archaea belong to this domain.
All bacteria lack a nucleus.
All bacteria are multicellular organisms.
All bacteria have a membrane-bound nucleus.
All bacteria lack a nucleus.
Which of the following statements regarding a common cellular activity is false?
New cells are derived from cellular components like organelles.
Life is organized in a hierarchical fashion. Which of the following sequences correctly lists that hierarchy from least inclusive to most inclusive?
molecule, organelle, cell, tissue, organ, organ system, organism, population, community, ecosystem
A hypothesis is
a proposed explanation for a set of observations.
Your instructor asks you to look into your microscope to see a prokaryotic cell. You will be looking for a cell that
has a membrane.
The role of a control in an experiment is to
provide a basis of comparison to the experimental group.
Which of the following is a kingdom within the domain Eukarya?
Fungi
What is the difference between a tissue and an organ system?
An organ system includes tissues.
Which of the following statements about the properties of life is false?
Organisms have the ability to reproduce.
Organisms have the ability to respond to stimuli from the environment.
Organisms have the ability to take in energy and use it.
Organisms have an unchanging, constant internal environment
Organisms have an unchanging, constant internal environment
A single water molecule (H—O—H) is held together by
two polar covalent bonds.
The sodium atom contains 11 electrons, 11 protons, and 12 neutrons. What is the mass number of sodium?
23
The figure below shows five water molecules. The hydrogen bonds shown in this figure are each
between an oxygen and a hydrogen atom of different water molecules.
What is the atomic mass of an atom that has 6 protons, 6 neutrons, and 6 electrons?
12
The hydrogen atoms of a water molecule are bonded to the oxygen atom by ________ bonds, whereas neighboring water molecules are held together by ________ bonds.
polar covalent; hydrogen
Compared to a solution of pH 3, a solution of pH 1 is
100 times more acidic.
Which of the following best describes the atomic number of an atom?
the number of protons in the atom
Changing the ______would change it into an atom of a different element.
number of protons in the nucleus of an atom
Water molecules stick to other water molecules because
hydrogen bonds form between the hydrogen atoms of one water molecule and the oxygen atoms of other water molecules.
A solution of pH 6 contains________H+ than the same amount of a solution at pH8.
100 times more
A can of cola consists mostly of sugar dissolved in water, with some carbon dioxide gas that makes it fizzy and makes the pH less than 7. In chemical terms, you could say that cola is an aqueous solution where water is the______, sugar is a _________, and carbon dioxide makes the solution_________.
solvent…solute…acidic
A solution with a pH of 7 is
neutral.
Household ammonia has a pH of 12; household bleach has a pH of 13. Which of the following statements about these substances is true?
A solution that could buffer the bleach and ammonia would remove excess OH- ions.
The ammonia has 10 times as many H+ ions as the bleach.
The ammonia has 10 times as many OH- ions as the bleach.
Both of these substances are strong acids.
The ammonia has 10 times as many H+ ions as the bleach.
Where are protons located in an atom
nucleus
Which of the following particles are found in the nucleus of an atom?
protons and neutrons
Which of the following statements regarding the oxygen atom of a water molecule is true?
Oxygen is more electronegative than the hydrogen atoms.
Which of the following statements best describes a compound?
A compound contains two or more different elements in a fixed ratio.
A hydrogen atom has one electron. How many covalent bonds can hydrogen form?
one
The four most common elements in living organisms are
C, H, O, N.
In a water molecule, hydrogen and oxygen are held together by a ________ bond.
polar covalent
Which of the following is a correct match?
mitochondria - protein alteration and packaging
lysosomes - cellular digestion
Golgi apparatus - production of cellular ATP
ribosomes - lipid synthesis
smooth endoplasmic reticulum - storage of water
lysosomes - cellular digestion
Which of the following correctly matches an organelle and its function?
mitochondrion - cellular respiration
All cells have some characteristics in common; both prokaryotic and eukaryotic cells have _________
cytoplasm, a plasma membrane, and DNA
Which feature is found in all cells?
plasma membrane composed of phospholipids
Which of the following is the correct sequence through the endomembrane system for material destined to be secreted from the cell?
rough endoplasmic reticulum - Golgi apparatus - plasma membrane
Golgi apparatus - ribosome - plasma membrane
smooth endoplasmic reticulum - plasma membrane - Golgi apparatus - ribosome
nucleus - smooth endoplasmic reticulum - Golgi apparatus
Golgi apparatus - smooth endoplasmic reticulum - plasma membrane
rough endoplasmic reticulum - Golgi apparatus - plasma membrane
Since the plasma membrane blocks the passage of all but a few molecules with specific traits, it is necessary for other molecules to __________
pass through the membrane via proteins.
There is an antibiotic called streptomycin that inhibits the function of bacterial ribosomes. Consequently, as the bacterial cells die, the person taking the antibiotics gets better. In other words, the antibiotic destroys bacteria by ______________
not allowing them to produce proteins.
Which organelles would be abundant in a sperm cell actively swimming toward an egg cell?
Golgi Apparatus
Lysosomes
Ribosomes
Mitochondria
Endoplasmic Reticulum
Mitochondria
Scientists have identified a mutation in an isolated community in central Africa that prevents individuals from detoxifying harmful organic molecules, leading to a high percentage of people who become ill after consuming alcohol. What cellular organelles does this mutation most likely affect the most?
Smooth endoplasmic reticulum
Due to the lack of an enzyme to break down lipids, excess accumulation of lipids in the brain leads to a human disease called Tay-Sachs syndrome. The organelle(s) most likely to lack the proper enzyme needed for lipid breakdown is/are _____________.
lysosomes
The function of mitochondria is
cellular respiration.
Match the cell to description.
pancreatic cell that secretes digestive enzymes
ovarian cell that produces estrogen (a steroid hormone)
muscle cell in the thigh of a long-distance runner
white blood cell that engulfs bacteria
pancreatic cell that secretes digestive enzymes
Cell with most rough ER
ovarian cell that produces estrogen (a steroid hormone)
Cell with most smooth ER
muscle cell in the thigh of a long-distance runner
Cell with most mitochondria
white blood cell that engulfs bacteria
Cell with most lysosomes
According to this figure, which of the following are large enough to see in the light microscope?
mitochondria
The nucleus of a cell
contains DNA.
The nucleoid region of a prokaryotic cell
contains the cell’s DNA.
The endomembrane system includes all of the following organelles except the
peroxisome.
Light microscopes
typically provide more resolution than an electron microscope.
are generally not used to view bacteria.
work by reflecting electrons off the surface of an object being studied.
use light and glass lenses to magnify an image.
use light and glass lenses to magnify an image.
The function of chloroplasts is
photosynthesis.
Which of the following structures is exclusively associated with prokaryotic cells?
chromosome
membrane-bound nucleus
nucleoid
ribosomes
nucleoid
The function of the nucleolus is
to manufacture ribosomal RNA
The antibiotic Streptomycin inhibits the function of bacterial ribosomes thus photosynthesis is stopped.
False
Which of the following cell structures are associated with the breakdown of harmful substances?
mitochondria
peroxisomes
chloroplasts
centrioles
peroxisomes
The Golgi apparatus
stores, modifies, and packages proteins.
is the site of carbohydrate breakdown.
is composed of stacks of membranous vesicles that are continuous with one another.
strings together amino acids to produce proteins.
stores, modifies, and packages proteins.
Which of the following is the correct sequence through the endomembrane system for material destined to be secreted from the cell?
nucleus, smooth endoplasmic reticulum, Golgi
rough endoplasmic reticulum, Golgi, plasma membrane
Golgi, Ribosome, plasma membrane
Golgi, smooth endoplasmic reticulum, plasma membrane
rough endoplasmic reticulum, Golgi, plasma membrane
A scientist wants to magnify a pollen grain 8,000 times and examine the ridges and pores on its surface. Which of the following instruments would be best?
an inverted light microscope
a transmission electron microscope
a scanning electron microscope
a fluorescence confocal microscope
a scanning electron microscope
The ultrastructure of a chloroplast is best studied using a
?
Which of the following statements regarding plasmodesmata is false?
Plasmodesmata carry nutrients between plant cells.
Plasmodesmata carry chemical messages between plant cells.
Plasmodesmata are found in plants as well as some single-celled organisms.
Plasmodesmata penetrate plant cell walls.
Plasmodesmata are found in plants as well as some single-celled organisms.
________ cells lack a membrane-enclosed nucleus.
Prokaryotic
In the plasma membrane, the phospholipid heads
are hydrophilic and face outward toward the aqueous solution on both sides of the membrane.
Unlike animal cells, plant cells have ________ and ________. Unlike plant cells, animal cells have ________.
chloroplasts; cell walls; centrioles
Which of the following statements about the ATP molecule is true?
It contains the sugar glucose
It releases energy when one phosphate group leaves ATP
It contains five phosphate groups
Extremely stable bonds link the second and third phosphate groups
It releases energy when one phosphate group leaves ATP
Most of the functions of a cell membrane, including transport and enzymatic function, are performed by
proteins
Which of the following substances would have the most trouble crossing a biological membrane by diffusing through the lipid bilayer?
Na+
O2
CO2
a small, nonpolar molecule such as butane (C4H10)
Na+
The synthesis of ATP from ADP and P
stores energy in a form that can drive cellular work
Facilitated diffusion across a biological membrane requires ________ and moves a substance ________ its concentration gradient.
transport proteins; down
Substrates bind to an enzyme’s ________ site.
active
The energy required to initiate an exergonic reaction is called
activation energy
Osmosis can be defined as
the diffusion of water
Which figure depicts an animal cell placed in a solution hypotonic to the cell?
cell A
Kinetic energy differs from chemical energy in that
kinetic energy is the energy of a moving object, whereas chemical energy is the potential energy of molecules.
According to ________, energy cannot be created or destroyed.
the first law of thermodynamics
The process of a white blood cell engulfing a bacterium is
phagocytosis
A cell that has neither a net gain of water nor net loss of water when it is immersed in a solution must be
isotonic to its environment
The fluid mosaic model describes the plasma membrane as consisting of
diverse proteins embedded in a phospholipid bilayer.
Phagocytosis is to eating as pinocytosis is to
drinking
In the lab, you use a special balloon that is permeable to water but not sucrose to make an “artificial cell.” The balloon is filled with a solution of 20% sucrose and 80% water and is immersed in a beaker containing a solution of 40% sucrose and 60% water. Which of the following will occur?
Sucrose will enter the balloon
Water will leave the balloon
Sucrose will leave the balloon
Water will enter the balloon
Water will leave the balloon
Which best describes the structure of a cell membrane?
proteins between two bilayers of phospholipids
proteins embedded in a bilayer of phospholipids
a bilayer of protein coating a layer of phospholipids
cholesterol embedded in a bilayer of phospholipids
proteins embedded in a bilayer of phospholipids
Diffusion does not require the cell to expend ATP. Therefore, diffusion is considered a type of
passive transport
Oxygen crosses a plasma membrane by
passive transport
In a hypotonic solution, an animal cell will
lyse
