BIO EXAM 2 QUESTIONS/ANSWERS
In attempt to visualize the fluid mosaic model of a membrane, we could describe the ______ as floating in a sea ________.
Proteins; lipids
Which statement best describes the relationship between the RNA and DNA?
RNA is a copy of DNA that makes his own proteins
What is a role of proteins found in a eukaryotic plasma membranes:
Regulating the flow of a material through the membrane
What activity occurs in the nucleolus?
Ribosome parts are created
A cell without nucleoli is probably not producing
Ribosomes
The cell organelle that organizes protein synthesis is
Ribosomes
The secondary cell wall in plants add:
Rigidity to the cell
If a cell membrane is pierced with a very fined needle, the cell will subsequently ______.
Seal itself
Golgi bodies appear to function in:
Secretion of cell products
Not all substances can cross the cell membrane, for this reason, the cell membrane is said to be
Selectively permeable
In eukaryotic cells, the endoplasmic reticulum can
Serve as the internal transportation system of a cell
What are cilia?
Short, eyelash-like projections from the cell membrane that provide for locomotion
Organelles involved in the synthesis of steroids and other lipids in gland cells are
Smooth ER
Which of the following involved in lipid synthesis and modification?
Smooth ER
If a plant synthesizes a secondary wall, it is laid down:
Between the plasma membrane and the primary cell wall
The process where water is removed between two amino acids to build a dipeptide is called a:
Dehydration synthesis
Four of the five items listed below are cytoplasmic organelles. Select the exception
Nucleolus
The cell organelle or structure that stores in DNA and synthesizes RNA is the
Nucleus
The subunits for ribosomes are synthesized in the
Nucleus
A peptide bond forms
-By the removal of a water molecule -By a dehydration reaction -Between two amino acids
What role(s) does the cytoskeleton play in a living cell? (Hint: Check only one answer)
-Maintaining cell shape -Movement -Contraction -Internal cell support
________ can readily diffuse across a lipid bilayer.
-Oxygen -Carbon Dioxide
This organelle is more likely to be found in an plant cell than in a animal cell
Central vacuole
Ezymes are
-Very specific -Are organic molecules -Act as catalysts -Have special shapes that control their activities
A prokaryote has
A cell membrane
For diffusion to occur in a given direction, there must be
A gradient
The fluid-mosaic model represents the modern view of
A membranes structure
What is similar about exporting proteins for a cell and digesting food particles within a cell?
Both processes involve the formation of vesicles
The cell wall of plants consist largely of
Carbohydrates
Plants need which of the following to carry on photosynthesis?
Carbon dioxide and water
A cytologist would principally investigate:
Cell and cell organelles
The outer limit of a living cell is always the:
Cell membrane
The part of the cell that regulates movement of substances into and out of the cell is the
Cell membrane
Provides structure and support outside the plant cells
Cell wall
We usually compare all eukaryotic cells as a group to all prokaryotic cells. However, some types of eukaryotic cells have characteristics that are found in prokaryotic cells, but not found in other eukaryotic cells. What feature do plant cells share with prokaryotic cells, but not animal cells?
Cell wall
The fluid filled sac that may store food, acids, vitamins, ions or water in plant cells and is involved in fluid
Central vacuole
Plant cells generally lack:
Centrioles
What organelle in higher plant cells contain chlorophyll?
Chloroplasts
Which organelle releases oxygen?
Chloroplasts
Inside the nuclear envelope the DNA maybe found in the form of fine diffuse strands is called
Chromatin
Four of the five structures listed below are composed of membranes. Select the exception. -Endoplasmic reticulum -Granum -Nuclear envelope -Plasma membrane -Chromosomes
Chromosome
Deoxyribonucleic acid (DNA) is believed to be the most important substance of:
Chromosomes
In all cells DNA is located in
Chromosomes
The "blueprints" or "computer tapes" in a cell that control all its activity are the
Chromosomes
What is the difference between cilia and flagella?
Cilia are much shorter than flagella
In general the net movement of molecules in a fluid is a response to the
Concentration gradient
Lysosomes
Contain digestive enzymes
The inner layer of the mitochondrial membrane may be invaginated (infolded) to form:
Cristae
Protein fibers in the cytoplasm maintain the three-dimensional structure of animal cells
Cytoskeleton
What is the exact function of DNA?
DNA provides the blueprints for making proteins
This illustration of which cell organelle?
Dictyosome
The organelle directly responsible for packaging and exporting cellular products is the:
Dictyosome (Golgi)
The cell organelle that processes and packages substances produced by the cell is?
Dictyosomes
The net movement of molecules from a high concentration to a low concentration is described by which of the following?
Diffusion
Nucleic acids confined to the nucleus or nucleoid indirectly
Direct protein synthesis out in the cytoplasm
The nucleic acid DNA can do only two things, one is to make RNA and other is to:
Duplicate itself
The primary structural difference between plant and animal cells is that most plant cells are:
Enclosed by a cell wall
What cellular process involves an inward sinking of a small patch of membrane to form a cytoplasmic vesicle?
Endocytosis
Which of the following are sometimes referred to as a rough or smooth depending on surface structure?
Endoplasmic reticula
The system of canals, tubes, and sacs that transport molecules inside the cytoplasm is the:
Endoplasmic reticulum
Which of these is not found in the nucleus?
Functioning ribosomes
Scientists demonstrated the fluidity of plasma membranes by
Fusing the membranes of two different species
Which animal cell junction correctly matched with its function? -Adhering; allows rapid flow of substance -Tight; holds cells together -Gap; connects cytoplasm of adjoining cells -Adhering; seals adjoining cells -Gap; prevents passage of materials
Gap; connects cytoplasm of adjoining cells
Which of the following organelles is correctly matched with its function? -Nucleus; protein synthesis -ER; heredity -Golgi bodies; packaging -Mitochondria; digestion -Chloroplasts; storage of lipids
Golgi bodies; packaging
Vesicles pinched off from the ER most likely are on their way to the
Golgi body
Chloroplasts contain disk-like membraneous sac arranged in stacks. The stacks are called
Grana
The term cell comes from this scientist's work and his description of the compartmentation he saw in thin slices of corks:
Hooke
In a lipid bilayer, ______ of lipid molecules are sandwiched between ________.
Hydrophobic tails; hydrophilic heads
As a result of its involvement in a reaction, an enzyme
Is unchanged
All cell membranes and organelle membranes consist of two phospholipid layers called a:
Lipid bilayer
Two _____ act as a barrier between the inside and the outside of the cell
Lipid bilayers
Which of the following is a function of the smooth endoplasmic reticulum?
Lipid manufacture
What are the flagella?
Long whip-like projections
Which of the following is a type of vesicle produced by the Golgi body?
Lysosome
The cell organelle that digests molecules, old organelles and foreigns substance inside cells is
Lysosomes
Which of the following contain enzymes, are the main organelles of intracellular digestion, and can digest whole cells?
Lysosomes
The largest cytoskeletal element is the:
Microtubule
Which of the components of cytoskeleton are used directly for movement?
Microtubules
Cells with high energy requirements, such as muscle (as in a humming bird), tend to have many
Mitochondria
Which of the following are the primary cellular sites for the release or capture of energy from carbohydrates?
Mitochondria
Which of the following organelles is most important in providing energy to the cells?
Mitochondrion
Which organelle below is capable of production its own protein?
Mitochondrium
This organelle is more likely to be found in an animal cell than in a plant cell: -Mitochondrion -Central vacuole -Cell membrane -Nucleus
None of the above
The RNA in the nucleus leaves through
Nuclear pores
The presence of which of the following features distinguishes prokaryotic cells from eukaryotic cells?
Nucleoid
Which structures are found in a prokaryotic cell?
Nucleoid, ribosomes, chloroplast, cell wall
Which of the following is a characteristic of DNA?
Occurs in all cells
A white blood cell is engulfing a bacterium is an example of ______.
Phagocytosis
Membranes are composed mainly of:
Phospholipids and proteins
Which structure(s) would be found in eukaryotic cells but NOT in prokaryotic cells?
Plastids and nuclear membrane
What is the smallest thing in the following list: -Mitochondrion -Prokaryote -Atom -Virus -Frog embryo
Prokaryote
Which of the following is a function of the Golgi apparatus?
Protein modification
Most membrane functions are carried out by ________.
Proteins
There are many kinds of ________ in cell membranes; they help to move material into and out of the cell
Proteins
What is the main product of the rough endoplasmic reticulum?
Proteins
What is the purpose of the cell wall?
Support and protection
If lysosomes bursts inside a cell, the immediate result is likely to be:
The cell will be digested within
Cilia and flagella are most similar in:
Their internal composition and structure
In a typical cell the substance found in the highest percentage is:
Water
In reference to diffusion, "passive" really means:
no ATP energy is required