DNA Flashcards
(297 cards)
1
Q
The transmission of traits from one generation to the next.
A
Heredity
2
Q
What fuses individual DNA fragments together?
A
DNA ligase
3
Q
A molecule of mRNA is a string of…
A
codons
4
Q
In most mammals, the organs that provides nutrients and oxygen to the embryo and helps dispose of its metabolic wastes. The placenta is formed of the embryo’s chorion and the mother’s endometrial blood vessels.
A
Placenta
5
Q
The systematic study of the full protein sets (proteomes) encoded by genomes.
A
Proteomics
6
Q
The cloning of human cells by nuclear transplantation for therapeutic purposes, such as the replacement of body cells that have been irreversibly damaged by disease or injury.
A
Therapeutic Cloning
7
Q
A set of three-nucleotide-long “words” that specify the amino acids for polypeptide chains.
A
Triplet Code
8
Q
A change in nucleotide sequence of DNA; a major source of genetic diversity. Any change to the genetic information of a cell or virus.
A
Mutation
9
Q
An organism that has acquired one or more genes by artificial means. If the gene is from another organism, typically of another species, the recombinant organism is also known as transgenic organism.
A
Genetically Modified Organisms (GMO)
10
Q
Containing two sets of chromosomes (pairs of homologous chromosomes) in each cell, one set inherited from each parent; referring to a 2n cell.
A
Diploid
11
Q
Do all nonreproductive cells have the same number of chromosomes?
A
Yes
12
Q
The first sign of cytokinesis during cell division in an animal cell; a shallow groove in the cell surface near the old metaphase.
A
Cleavage Furrow
13
Q
Artificial cloning is widely used in…
A
agriculture
14
Q
A technique in which the nucleus of one cell is placed into another cell that already has a nucleus or in which the nucleus has been previously destroyed. The cell is then stimulated to grow, producing an embryo that is a genetic copy of the nucleus donor.
A
Nuclear Transplantation
15
Q
A molecule of DNA produced from a long DNA molecule cut up by a restriction enzyme; used in genome mapping and other applications.
A
Restriction Fragments
16
Q
On mRNA, the specific three-nucleotide sequence (AUG) to which an initiator tRNA molecule binds, starting translation of genetic information.
A
Start Codon
17
Q
In eukaryotes, a coding portion of a gene.
A
Exons
18
Q
How many different alleles can an individual carry for a particular gene?
A
At most, two.
19
Q
Methods used to study or manipulate genetic material.
A
DNA Technology
20
Q
A chemical group consisting of a phosphorus atom bonded to four oxygen atoms; found in such molecules as DNA and the phospholipids that constitute cellular membranes.
A
Phosphate
21
Q
The type of ribonucleic acid that encodes genetic information from DNA and conveys it to ribosomes, where the information is translated into amino acid sequences.
A
Messenger RNA (mRNA)
22
Q
A model for DNA replication in which the replicated double helix consists of one old strand, derived from the old molecule, and one newly made strand short tandem repeats (STRs), signal transduction pathway.
A
Semi-Conservative
23
Q
What percent of a cell’s lifetime is spent in interphase?
A
90%
24
Q
What do animal cells have that plant cells do not?
A
Lysosome
25
A cyclically operating set of proteins that triggers and coordinates events in the eukaryotic cell cycle.
Cell Cycle Control System
26
What produces recombinant chromosomes?
Crossing over.
27
How do ribosomes work with codons?
Within the cytoplasm, the ribosomes read each successive codon and attach the proper amino acid to a growing chain.
28
A chromosome not directly involved in determining the sex of an organism; in mammals, for example, any chromosome other than X or Y.
Autosomes
29
A cellular structure consisting of RNA and protein organized into two subunits and functioning as the site of protein synthesis in the cytoplasm. The ribosomal subunits are constructed in the nucleolus.
Ribosomes
30
A location within the nucleus where DNA from multiple chromosomes directs the production of a kind of RNA called ribosomal RNA.
Nucleolus
31
Substitutes one amino acid for another. This produces a mutant protein, which may be nearly identical to or substantially different from the original.
Missense Mutation
32
A gene whose product inhibits cell division, thereby preventing uncontrolled cell growth.
Tumor-Suppressor Genes
33
mRNA molecules leave the nucleus through...
the nuclear pores
34
The study of whole sets of genes and their interactions.
Genomics
35
In heterozygotes, the allele that has no noticeable effect on the phenotype.
Recessive Allele
36
A string of amino acids is...
a polypeptide.
37
Translation begins when...
ribosome parts assemble around a molecule of mRNA.
38
DNA consisting of tandem (in a row) repeats of a short sequence of nucleotides.
Short Tandem Repeats (STR)
39
Cytokinesis in animal cells and in some protists, characterized by pinching in of the plasma membrane. In animal development, the succession of rapid cell divisions without cell growth, converting the animal zygote to a ball of cells.
Cleavage
40
Chromosomes that contain DNA sequences derived from two parent chromosomes, making them a patchwork of regions derived from both parent chromosomes.
Recombinant Chromosomes
41
A chemical or physical agent that interacts with DNA and causes a mutation.
Mutagens
42
A pair of ovaries are the female gonads. Each ovary produces eggs.
Ovary
43
In the eukaryotic cell, a protein that functions in initiating or regulating transcription. --- bind to DNA or to other proteins that bind to DNA.
Transcription Factors
44
How is mitosis and meiosis different?
Like mitosis, meiosis involves duplication of the chromosomes before division starts. But during meiosis, there are two rounds of cell division (whereas mitosis has only one).
45
A condition in which a person has three copies of chromosome 21 for a total of 47 chromosomes.
Trisomy 21
46
A type of ribonucleic acid that functions as an interpreter in translation. Each --- molecule has a specific anticodon, picks up a specific amino acid, and conveys the amino acid to the appropriate codon on mRNA.
Transfer RNA (tRNA)
47
Independent assortment happens when...
the side-by-side orientation of each homologous pair of chromosomes is a matter of chance. It can be either red/blue or blue/red.
48
The expressed traits of an organism.
Phenotype
49
In female mammals, the inactivation of one X chromosome in each somatic cell. Once X inactivation occurs in a given cell (during embryonic development), all descendants of that cell will have the same copy of the X chromosome inactivated.
X Chromosome Inactivation
50
As the cells separate, the cleavage furrow...
contracts like the pulling of a drawstring on a hoodie, deepening the furrow.
51
The direct manipulation of genes for practical purposes.
Genetic Engineering
52
Who was able to create the basic principles of inheritance?
Gregor Mendel
53
Everything inside a eukaryotic cell between the plasma membrane and the nucleus; consists of a semifluid medium and organelles; can also refer to the interior of a prokaryotic cell.
Cytoplasm
54
Treatment for cancer in which parts of the body that have cancerous tumors are exposed to high-energy radiation to disrupt cell division of the cancer cells.
Radiation Therapy
55
One of the two identical parts of a duplicated chromosome. While joined, two --- make up one chromosome; --- are eventually separated during mitosis or meiosis 2.
Sister Chromatids
56
Where does translation take place?
Translation takes place within the cytoplasm in cellular structures called ribosomes.
57
Nondisjunction is the most common reason for...
a loss of pregnancy.
58
What happens to an RNA molecule before it leaves the nucleus?
It is processed.
59
A naturally occurring enzyme that assembles DNA nucleotides into polynucleotides using a pre existing strand of DNA as a template.
DNA Polymerase
60
How does the chromatin differ whether the cell is dividing or not?
When a cell is not dividing, much of the chromatin is very loose, but it coils tightly during cell division.
61
A type of inheritance in which the phenotype of a heterozygous (Aa) is intermediate between the phenotypes of the two types of homozygotes (AA and aa).
Incomplete Dominance
62
Does not change the amino acid produced (because some amino acids are encoded by more than one RNA sequence), so the protein is unchanged.
Silent Mutation
63
Parts of an Idealized Plant Cell
Nucleus, ribosomes, cytoskeleton, golgi apparatus, vesicle, cytoplasm, central vacuole, cell wall of adjoining cell, cell wall, plasma membrane, chloroplast, mitochondria, and nuclear envelope.
64
Sources of stem cells.
An embryo is rich in stem cells. Other sources include adult bone marrow and umbilical cord blood.
65
How many chromosomes does each human body cell have?
46 chromosomes.
66
An international collaborative effort that sequenced the DNA of the entire human genome.
Human Genome Project
67
A double membrane, perforated with pores, that encloses the nucleus and separates it from the rest of the eukaryotic cell.
Nuclear Envelope
68
The type of ribonucleic acid that, together with proteins, makes up ribosomes; the most abundant type of RNA.
Ribosomal RNA (rRNA)
69
In mRNA, one of three triplets (UAG, UAA, UGA) that signal gene translation to stop STR analysis.
Stop Codons
70
Mutations that add nucleotides.
Insertions
71
The inner lining of the uterus in mammals, richly supplied with blood vessels that provide the maternal part of the placenta and nourish the developing embryo.
Endometrium
72
In a heterozygote, the allele that determines the phenotype with respect to a particular gene.
Dominant Allele
73
Where does translation occur?
The new RNA molecule carries instructions for making a protein from the nucleus to the cytoplasm, where translation at the ribosomes occurs.
74
What happens in a ribosome?
Molecules of transfer RNA (tRNA) translate triplets of RNA nucleotides into amino acids using a specific genetic code.
75
The complete set of genetic material of an organism or virus.
Genome
76
Mutations that remove nucleotides.
Deletions
77
Sexual reproduction depends on...
meiosis
78
A specific sequence on a DNA strand that is recognized and cut by a restriction enzyme.
Restriction Site
79
How does the meiosis phase 2 stage work?
During the meiosis 2 phase, in each of the two cells produced by meiosis 1, the chromosomes condense (prophase 2) and line up singly in the center of the cell (metaphase 2). The sister chromatids split apart, with one copy distributed to each side of the cell (anaphase 2). At the end of meiosis 2, each cell splits by cytokinesis. The nuclear membranes reform, and the chromosomes uncondense (telophase 2).
80
How to produce large quantities of a desired human protein?
A gene that synthesizes the wanted protein is isolated and inserted into a piece of bacterial DNA called a plasmid.
81
A variant of a character found within a population, such as purple flowers in pea plants.
Traits
82
Single-celled organisms can reproduce asexually by...
binary fission
83
All eukaryotic cells are surrounded by...
a plasma membrane, and some, such as plant cells, also have an outer cell wall.
84
Upon reaching the end of the mRNA...
the newly formed polypeptide is released, and the ribosome disassembles back into its parts.
85
The genetic material that organisms inherit from their parents; a double-stranded helical macromolecule consisting of nucleotide monomers with deoxyribose sugar, a phosphate group, and nitrogenous bases adenine (A), cytosine (C), guanine (G), and thymine (T).
Deoxyribonucleic Acid (DNA)
86
How much does DNA increase after a round in a thermal cycler?
The quantity is doubled.
87
The creation of genetically identical offspring by a single parent, without the participation of gametes.
Asexual Reproduction
88
A small, single-stranded RNA molecule that associates with one or more proteins in a complex that can degrade or prevent translation of an mRNA with a complementary sequence.
MicroRNAs (miRNA)
89
The turning on and off of specific genes within a living organism.
Gene Regulation
90
A chromosome that determines whether an individual is male or female; in mammals, these are the X and Y chromosomes.
Sex Chromosomes
91
If the tumor gains the potential to spread to other tissues, the person is said to have...
cancer.
92
How to perform an STR analysis?
To perform an STR analysis, a forensic scientist obtains DNA from two or more samples and then uses the polymerase chain reaction to produce large quantities for comparison.
93
A series of molecular changes that converts a signal received on a target cell’s surface to a specific response inside the cell.
Signal Transduction Pathway
94
A method of DNA profiling that compares the lengths of STR sequences at specific sites in the genomes.
STR Analysis
95
What holds the two DNA strands together?
Hydrogen bonds.
96
How many stop codons are there?
There are three stop codons, any one of which can signal the end of the message.
97
The genetic makeup of an organism.
Genotype
98
A protein secreted by certain body cells that stimulates other cells to divide.
Growth Factor
99
Where do some proteins go after being produced at ribosomes?
After being produced at ribosomes, some proteins travel through the cytoplasm to the Golgi apparatus. One side of the Golgi receives vesicles containing newly made proteins.
100
Having two different alleles for a given gene.
Heterozygous
101
One of the most important steps in any genetic engineering project is to...
cut and paste specific pieces of DNA.
102
A laboratory device that performs PCR.
Thermal Cycler
103
An abnormal tissue mass that spreads into neighboring tissue and to other parts of the body; a cancerous tumor.
Malignant Tumor
104
How does the base-pairing rules work?
The sequence of nucleotides along one polynucleotide within a double helix dictates the identity of nucleotides along the other polynucleotide.
105
As a verb, to produce genetically identical copies of a cell, organism, or DNA molecule. As a noun, the collection of cells, organisms, or molecules resulting from cloning; also (colloquially), a single organism that is genetically identical to another because it arose from the cloning of a somatic cell.
Clones
106
The form assumed by DNA in living cells, referring to its two adjacent polynucleotide strands wound into a spiral shape.
Double Helix
107
Transcription begins when...
RNA polymerase binds to a specific region of DNA.
108
The unit of heredity?
The unit of heredity is the gene, a stretch of DNA that encodes information needed to produce a specific molecule.
109
What does CRISPR-Cas9 do?
The CRISPR-Cas9 system is a technology that allows the nucleotide sequence of specific genes to be edited in living cells.
110
How many mRNA nucleotides can a ribosome read at a time?
Three
111
An organic monomer consisting of a central five-carbon sugar covalently bonded to a nitrogenous base and a negatively charged phosphate group. --- are the building blocks of nucleic acids.
Nucleotides
112
A stage of mitosis during which sister chromatids split apart, separate from each other, and more to opposite sides of the cell.
Anaphase
113
A cancer-causing agent, either high-energy radiation (such as X-rays or UV light) or a chemical.
Carcinogens
114
The synthesis of RNA on a DNA template.
Transcription
115
The parent individuals from which offspring are derived in studies of inheritance. P stands for parental.
P Generation
116
A technique for sorting macromolecules. A mixture of molecules is placed on a gel between a positively charged electrode and a negatively charged one; negative charges on the molecule are attracted to the positive electrode, and the molecules migrate toward that electrode. The molecules separate in the gel according to their rates of migration.
Gel Electrophoresis
117
A human genetic disorder from a condition called trisomy 21, the presence of an extra chromosome 21; characterized by heart and respiratory defects and varying degrees of mental retardation.
Down Syndrome
118
An organelle in eukaryotic cells consisting of stacks of membranous sacs that modify, store, and ship products of the endoplasmic reticulum.
Golgi Apparatus
119
On a tRNA molecule, a specific sequence of three nucleotides that is complementary to a codon triplet on mRNA.
Anticodon
120
Where are ribosomes?
Some ribosomes are bound to the membrane of the rough ER; others float freely in the cytoplasm.
121
What percent of couples are infertile?
15%
122
A developing human from the 9th week of pregnancy until birth. The fetus has all the major structures of an adult.
Fetus
123
The embryonic stage resulting from gastrulation in animal development. Most animals have a --- made up of three layers of cells: ectoderm, endoderm, and mesoderm.
Gastrula
124
The longest section of the alimentary canal. It is the principal site of the enzymatic hydrolysis of food molecules and absorption of nutrients.
Small Intestine
125
A protein-lined opening in the nuclear envelope through which materials (such as messenger RNA) can pass between the nucleus and the cytoplasm.
Nuclear Pores
126
A stage of mitosis during which duplicated chromosomes condense and the mitotic spindle forms.
Prophase
127
Compared to prokaryotic cells, eukaryotic cells are...(size)
relatively large (about ten times bigger) and more complex.
128
During embryonic development, the influence of one group of cells on an adjacent group of cells.
Induction
129
A bacterial plasmid that contains foreign DNA.
Recombinant Plasmid
130
With respect to DNA, one of the three parts that constitutes a nucleotide.
Sugar
131
The start codon also codes for what amino acid?
Methoionine
132
The thin layer of lipids and proteins that sets a cell off from its surroundings and acts as a selective barrier to the passage of ions and molecules into and out of the cell; consists of a phospholipid bilayer in which proteins are embedded.
Plasma Membrane
133
Cancer always begins when...
the DNA within a single cell undergoes a series of mutations.
134
In DNA technology, a labeled single-stranded nucleic acid molecule used to find a specific gene or other nucleotide sequence within a mass of DNA. The probe hydrogen-bonds to the complementary sequence in the targeted DNA.
Nucleic Acid Probe
135
What happens 3 weeks after fertilization?
By the third week after fertilization, the embryo is attached to the wall of the uterus, and several important early structures have begun to develop.
136
Before a cell can divide, it must...
duplicate all its chromosomes.
137
An ordered sequence of events (including interphase and the mitotic phase) that extends from the time a eukaryotic cell is first formed from a dividing parent cell until its own division into two cells.
Cell Cycle
138
What causes Down Syndrome?
Trisomy 21
139
Multicellular life depends on...
cell-to-cell signaling.
140
An individual who is heterozygous for a recessively inherited disorder and who therefore does not show symptoms of that disorder.
Carrier
141
Where does transcription occur?
Protein production begins in the nucleus, where transcription results in the production of a RNA molecule from DNA.
142
A series of strong, rhythmic uterine contractions that expels a baby out of the uterus and vagina during childbirth.
Labor
143
What builds new DNA?
Polymerase.
144
What are in each ribosome?
Within each ribosome are binding sites for the mRNA and molecules of transfer RNA.
145
A contagious disease spread by sexual contact; also called sexually transmitted diseases (STDs).
Sexually Transmitted Infections (STI)
146
What contains most of a cell’s DNA?
The nucleus contains most of a cell’s DNA stored in chromosomes.
147
The correspondence between an mRNA codon and its amino acid is called...
the triplet code.
148
The union of a haploid sperm cell with a haploid egg cell, producing a zygote.
Fertilization
149
A gene located on a sex chromosome.
Sex-Linked Genes
150
What happens 7 days after fertilization?
By day 7, the early embryo has reached the uterus and begun to implant in the endometrium lining. The embryo is now a fluid-filled ball of about 100 cells called a blastocyst.
151
A DNA molecule carrying genes derived from two or more sources, often from different species.
Recombinant DNA
152
Using a somatic cell from a multicellular organism to make one or more genetically identical individuals.
Reproductive Cloning
153
Eukaryotic cells are found in
All non prokaryotic forms of life, including plants and animals.
154
The mating between an individual of unknown genotype for a particular character and an individual that is homozygous recessive for that same character.
Testcross
155
What does the nuclear membrane do?
The nuclear membrane controls the passage of materials into and out of the nucleus.
156
The entire collection of DNA segments from an organism’s genome. Each segment is usually carried by a plasmid or phage.
Genomic Library
157
The last stage of the cell cycle during which the cytoplasm is divided and distributed to two new offspring cells.
Cytokinesis
158
The entire sequence of stages in the life of an organism, from the adults of one generation to the adults of the next.
Life Cycle
159
DNA functions as...
the molecule of heredity, transmitting genetic information from one generation to the next.
160
How do chromosomes control the cell’s activities?
By directing protein production. The DNA issues orders (via RNA) that result in proteins being built to perform needed tasks.
161
Random fertilization is when...
one gamete with random chromosomes fertilizes another gamete with random chromosomes, the result is great variation in the 46 chromosomes that can end up in the zygote.
162
A special sequence of nucleotides in DNA that marks the end of a gene. It signals RNA polymerase to release the newly made RNA molecule, which then departs from the gene.
Terminator
163
Ways to reduce the risk of cancer and increase the odds of survival include:
Having a healthy diet, not smoking, sun protection, regular screenings, and exercise.
164
A normal gene that can be converted to a cancer-causing gene.
Proto-Oncogene
165
Because the hereditary information of all life is written in the identical chemical language of DNA, a gene from one species...
may be cut and pasted into the DNA of a different species.
166
The offspring of two parental (P generation) individuals. F1 stands for first filial.
F1 Generation
167
The additive effect of two or more genes on a single phenotypic character.
Polygenic Inheritance
168
A network of interconnected membranous tubules in a eukaryotic cell’s cytoplasm. ---lacks ribosomes. Enzymes embedded in the --- membrane function in the synthesis of certain kinds of molecules, such as lipids.
Smooth ER
169
What does each kind of restriction enzyme do?
Each kind of restriction enzyme recognizes just one short sequence of DNA and cuts the DNA at a specific location within that sequence.
170
A cluster of cells surrounding, protecting, and nourishing a developing egg cell in the ovary. The --- also secretes estrogen.
Follicle
171
A family tree representing the occurrence of heritable traits in parents and offspring across a number of generations.
Pedigree
172
The growth and specialization of cells and tissues that occur as the cells of a zygote multiply and differentiate to form a multicellular organism.
Development
173
A DNA molecule made in vitro using mRNA as a template and the enzyme reverse transcriptase. A --- molecule therefore corresponds to a gene but lacks the introns present in the DNA of the genome.
Complementary DNA (cDNA)
174
When does prophase begin?
It begins when the nuclear membrane dissolves.
175
The theory that all living things are composed of cells and that all cells come from other cells.
Cell Theory
176
The location of Short Tandem Repeats (STR) within chromosomes and the sequences that are repeated are...
identical from person to person. But the number of repeats varies widely within the human population.
177
The combination of DNA and proteins that constitutes chromosomes; often used to refer to the diffuse, very extended form taken by the chromosomes when a eukaryotic cell is not dividing.
Chromatin
178
Having two identical alleles for a given gene.
Homozygous
179
The removal of introns and joining of exons in eukaryotic RNA, forming an mRNA molecule with a continuous coding sequence; occurs before mRNA leaves the nucleus.
RNA Splicing
180
The control of more than one phenotypic character by a single gene.
Pleiotropy
181
An enzyme that links together the growing chain of RNA nucleotides during transcription, using a DNA strand as a template.
RNA Polymerase
182
How is DNA replication accomplished?
Within a cell, the process of DNA replication is accomplished by a series of enzymes that work together to duplicate a DNA molecule.
183
What is a polynucleotide?
Each polynucleotide is a long strand of individual nucleotides.
184
The subset of the cell cycle in eukaryotes during which the cell is not dividing and is going about its usual activities.
Interphase
185
The manipulation of living organisms to perform useful tasks. Today, biotechnology often involves DNA technology.
Biotechnology
186
The process by which a DNA molecule is copied.
DNA Replication
187
A treatment for a disease in which the patient’s defective gene is supplemented or altered.
Gene Therapy
188
The division of a single nucleus into two genetically identical daughter nuclei.
Mitosis
189
The region of a chromosome where two sister chromatids are joined and where spindle microtubules attach during mitosis and meiosis. The --- divided at the onset of anaphase during mitosis and anaphase 2 of meiosis.
Centromere
190
The phenotypic trait that is less commonly observed in natural populations; the opposite of the wild-type trait.
Mutant Trait
191
The combination of DNA and proteins that constitutes chromosomes; often used to refer to the diffuse, very extended form taken by the chromosomes when a eukaryotic cell is not dividing.
Chromatin
192
In a sexually reproducing organism, the process of cell division that produces haploid gametes from diploid cells within the reproductive organs.
Meiosis
193
A spindle-shaped structure formed of microtubules and associated proteins that is involved in the movement of chromosomes during mitosis and meiosis. (A spindle is shaped roughly like a football).
Mitotic Spindle
194
The phase of the cell cycle when mitosis divides the nucleus and distributes its chromosomes to the daughter nuclei and cytokinesis divides the cytoplasm, producing daughter cells.
Mitotic Phase
195
A structure containing arteries and veins that connects a developing embryo to the placenta of the mother.
Umbilical Cord
196
A diagram used in the study of inheritance to show the results of random fertilization.
Punnett Square
197
A membranous disk that forms across the midline of a dividing plant cell. During cytokinesis, the --- grows outward, accumulating more cell wall material and eventually fusing into a new cell wall.
Cell Plate
198
The result of infertility, the inability to conceive after one year of trying.
About 15% of couples are infertile.
Infertile
199
A heritable feature that varies among individuals within a population, such as flower color in pea plants.
Character
200
Where does transcription occur in a eukaryotic cell?
The nucleus
201
The ribosome acts like a...
vice holding the various components together.
202
The fertilized egg, which is diploid, that results from the union of haploid gametes during fertilization.
Zygote
203
A change in a single nucleotide pair of a gene. The simplest type of mutation.
Point Mutation
204
The deliberate prevention of pregnancy.
Contraception
205
Genes located close enough together on a chromosome that they are usually inherited together.
Linked Genes
206
A procedure that analyzes an individual’s unique collection of genetic markers using PCR and gel electrophoresis. DNA profiling can be used to determine whether two samples of genetic material were derived from the same individual.
DNA Profiling
207
Many human characters are controlled by...
a single gene.
208
Containing a single set of chromosomes; referring to an n cell.
Haploid
209
A technique used to obtain many companies of a DNA molecule or many copies of part of a DNA molecule. A small amount of DNA mixed with the enzyme DNA polymerase, DNA nucleotides, and a few other ingredients replicates repeatedly in a test tube.
Polymerase Chain Reaction (PCR)
210
A digestive organelle in eukaryotic cells; contains enzymes that digest the cell’s food and wastes. It can dissolve large food particles, old cellular components, or invasive organisms such as bacteria.
Lysosomes
211
A mating of two sexually reproducing individuals.
Genetic Cross
212
In eukaryotes, a non expressed (noncoding) portion of a gene that is excised from the RNA transcript.
Introns
213
Also called the fallopian tube, contains cilia that sweep the egg toward the uterus.
Oviduct
214
The production of many identical copies of a specific segment of DNA.
DNA Cloning
215
Instead of deoxyribose, RNA has...
ribose.
216
Change an amino acid codon to a stop codon. This will produce a shortened protein that is almost always defective.
Nonsense Mutation
217
A master control gene that determines the identity of a body structure of a developing organism, presumably by controlling the developmental fate of groups of cells. (In plants, such genes are called organ identity genes).
Homeotic Genes
218
A narrow opening between the uterus and vagina. During birth, the cervix widens, allowing the baby to pass.
Cervix
219
An extensive membranous network in a eukaryotic cell, continuous with the outer nuclear membrane and composed of ribosome-studded (rough) and ribosome-free (smooth) regions.
Endoplasmic Reticulum (ER)
220
A general rule of inheritance, first proposed by Gregor Mendel, that states that when gametes form during meiosis, each pair of alleles for a particular character segregate independently of each other pair.
Law of Independent Assortment
221
Short, artificially created, single-stranded DNA molecules that bind to each end of a target sequence during a PCR procedure.
Primers
222
Parts of an Idealized Animal Cell
Nucleus, nuclear envelope, endoplasmic reticulum, mitochondria, flagellum, cytoplasm, cytoskeleton, plasma membrane, vesicle, golgi apparatus, ribosomes, and lysosomes.
223
Single DNA strands located at either end of a segment of DNA that has been chopped by a restriction enzyme. Two pieces of DNA cut by the same restriction enzymes will have complementary --- that will bind together to form a new DNA double helix.
Sticky Ends
224
An abnormal mass of cells that forms within otherwise normal tissue.
Tumor
225
Two DNA nucleotides, one from each polynucleotide strand in a DNA double helix, joined by hydrogen bonds. In DNA, the two types of base pairs are A-T and C-G.
Base Pairs
226
Instead of thymine, RNA has...
Uracil.
227
A gene-carrying structure found in the nucleus of a eukaryotic cell and most visible during mitosis and meiosis; also, the main gene-carrying structure of a prokaryotic cell. Each --- consists of one very long threadlike DNA molecule and associated proteins.
Chromosomes
228
What can PCR do?
Starting from just a single copy, automated PCR can generate billions of copies of a DNA segment in just a few hours, and it can do so with an extremely high rate of accuracy.
229
The process whereby genetic information flows from genes to proteins; the flow of genetic information from the genotype to the phenotype: DNA → RNA → protein.
Gene Expression
230
The trait most commonly found in nature.
Wild-Type Trait
231
DNA and RNA consist of...
a sugar, phosphate, and a base.
232
Mammalian embryo made up of a hollow ball of cells that results from cleavage and that implants in the mother’s endometrium.
Blastocyst
233
A mating of two organisms that are heterozygous for one character.
Monohybrid Cross
234
The ribosome exists as...
two separate components: the large and small subunits.
235
A cancer-causing gene; usually contributes to malignancy by abnormally enhancing the amount or activity of a growth factor made by the cell.
Oncogene
236
A mutation occurring when nucleotides are inserted in or deleted from a gene and the number inserted or deleted is not a multiple of three, resulting in the improper grouping of the subsequent nucleotides into codons.
Frameshift Mutation
237
A method for determining the DNA sequence of an entire genome by cutting it into small fragments, sequencing each fragment, and then placing the fragments in the proper order. This method combines several separate techniques that together can produce a wealth of data very quickly.
Whole-Genome Shotgun Method
238
What does Cas9 do?
A protein called Cas9 cuts DNA at locations that are complementary to a molecule of guide RNA.
239
The two chromosomes that make up a matched pair in a diploid cell. --- are of the same length, centromere position, and staining pattern and possess genes for the same characters at corresponding loci. One --- is inherited from the organism’s father, the other from the mother.
Homologous Chromosomes
240
In vertebrate animals, the extraembryonic membrane that encloses the fluid-filled amniotic sac containing the embryo.
Amnion
241
The creation of genetically distinct offspring by the fusion of two haploid sex cells, forming a diploid zygote.
Sexual Reproduction
242
The exchange of segments between chromatids of homologous chromosomes during prophase 1 of meiosis.
Crossing Over
243
A mating of two organisms that are each heterozygous for two characters.
Dihybrid Cross
244
What happens 36 hours after fertilization?
Starting about 36 hours after fertilization, the zygote undergoes cleavage.
245
Any cell in a multicellular organism except a sperm or egg cell or a cell that develops into a sperm or egg; a body cell.
Somatic Cells
246
What do plant cells have that animals cells do not?
Chloroplast, cell wall, and central vacuole.
247
The synthesis of a polypeptide using the genetic information encoded in an mRNA molecule. There is a change of “language” from nucleotides to amino acids.
Translation
248
How similar is the DNA between two humans?
The DNA of two humans of the same sex is about 99.5% identical.
249
A malignant growth or tumor caused by abnormal and uncontrolled cell division.
Cancer
250
How does gene therapy work?
Enzymes are used to produce an RNA version of the target DNA gene. This RNA gene is then combined with an infectious, but harmless, retrovirus. Once a recombinant retrovirus has been engineered to carry the normal gene, that gene needs to get inside the cells of a person with the disease.Bone marrow cells are ideally suited for this purpose because they multiply continuously, producing the normal protein for a long time.
251
The final stage of mitosis during which chromosomes uncondense and new nuclei form at the two poles of a cell.
Telophase
252
The existence of more than two common versions of a gene. For example, the gene that determines human blood type (ABO) comes in three common varieties.
Multiple Alleles
253
What happens as RNA synthesis continues?
As RNA synthesis continues, the growing RNA strand falls away from the DNA, allowing the two separated DNA strands to rejoin in the region already transcribed.
254
A three-nucleotide sequence in mRNA that specifies a particular amino acid or polypeptide termination signal; the basic unit of the genetic code.
Codons
255
A polymer made up of many nucleotides covalently bonded together.
Polynucleotides
256
The cleavage furrow consists of...
a ring of protein filaments in the cytoplasm just under the plasma membrane.
257
Development involves frequent cell division that must be...
carefully coordinated.
258
When did genomics begin?
The science of genomics began in 1995, when a team of biologists determined the entire genome of Haemophilus influenzae, a disease-causing bacterium.
259
An enzyme, essential for DNA replication, that catalyzes the covalent bonding of adjacent DNA nucleotides; used in genetic engineering to paste a specific piece of DNA containing a gene of interest into a bacterial plasmid or other vector.
DNA Ligase
260
A specific nucleotide sequence in DNA, located near the start of a gene, that is the binding site for RNA polymerase and the place where transcription begins.
Promoter
261
A form of genetic inheritance in which a heterozygous individual displays traits of both alleles.
Codominant
262
The reproduction of a cell.
Cell Division
263
As a result of gel electrophoresis...
smaller pieces of DNA migrate toward the bottom of the gel faster than larger pieces.
264
A network of interconnected membranous sacs in a eukaryotic cell’s cytoplasm. --- membranes are studded with ribosomes that make membrane proteins and secretory proteins. The rough ER constructs membranes from phospholipids and proteins.
Rough ER
265
A general rule of inheritance, first proposed by Gregor Mendel, that states that the two alleles in a pair segregate (separate) into different gametes during meiosis.
Law of Segregation
266
Within a eukaryotic cell, a hollow sac or bubble formed by a membrane that is used to transport materials.
Vesicles
267
The Y chromosome...
very small and carries virtually no genes other than the ones that confer maleness.
268
What happens when RNA polymerase binds at the promoter?
RNA polymerase peels open the double helix of DNA, exposing the two strands.
269
An enzyme that catalyzes the synthesis of DNA on an RNA template.
Reverse Transcriptase
270
Treatment for cancer in which drugs are administered to disrupt cell division of the cancer cells.
Chemotherapy
271
An organism that contains genes from another organism, typically of another species.
Transgenic Organisms
272
An accident of meiosis or mitosis in which a pair of homologous chromosomes or a pair of sister chromatids fail to separate at anaphase.
Nondisjunction
273
A display of micrographs of the metaphase chromosomes of a cell, arranged by size and centromere position.
Karyotype
274
What happens during interphase?
During interphase, a cell roughly doubles in size by building cytoplasm and organelles, and the chromosomes remain in an uncondensed state.
275
Translation begins when an mRNA molecule binds to...
a small ribosomal subunit.
276
The spread of cancer cells beyond their original state.
Metastasis
277
The most prominent organelle, a membrane-bound region where most of a cell’s DNA is housed.
Nucleus
278
How does replication begin?
Replication begins when an enzyme called helicase attaches to specific DNA sequences called origins of replication.
279
A unit of inheritance in DNA (or RNA, in some viruses) consisting of a specific nucleotide sequence that programs the amino acid sequence of a polypeptide. Most of the --- of a eukaryote are located in its chromosomal DNA; a few are carried by the DNA of mitochondria and chloroplasts.
Genes
280
The genetic material that organisms inherit from their parents; a double-stranded helical macromolecule consisting of nucleotide monomers with deoxyribose sugar, a phosphate group, and nitrogenous bases adenine (A), cytosine (C), guanine (G), and thymine (T).
Deoxyribonucleic Acid (DNA)
281
What happens 9 days after fertilization?
Starting on day 9, the cells begin to migrate within the blastocyst, organizing themselves into three main layers.
282
What happens to a protein as it goes through the Golgi?
As a protein travels through the Golgi, it is modified by enzymes, emerging as a refined product. The modified protein then travels in vesicles that may be transported within the cell or exported outside of it.
283
What are the two overlapping stages of the mitotic phase?
Mitosis and cytokinesis.
284
An abnormal mass of cells that remains at its original site in the body.
Benign Tumor
285
Predicting the results of a genetic cross with a Punnett square requires...
following genes from one generation to the next.
286
A polymer consisting of many nucleotide monomers; serves as a blueprint for proteins and, through the actions of proteins, for all cellular structures and activities. The two types of --- are DNA and RNA.
Nucleic Acids
287
A stage of mitosis during which duplicated chromosomes line up at the center of the cell with each chromosome attached to the mitotic spindle.
Metaphase
288
Each DNA strand binds to?
Each of the two separated DNA strands is bound by an enzyme called DNA polymerase.
289
What are information storage molecules that contain directions for the production of other molecules?
Nucleic acids, DNA and RNA
290
What enzyme starts DNA replication?
Helicase
291
A bacterial enzyme that cuts up foreign DNA at one very specific nucleotide sequence, thus protecting bacteria against intruding DNA from phages and other organisms. ---s are used in DNA technology to cut DNA molecules in reproducible ways.
Restriction Enzymes
292
What can the genomic library be used for?
Once created, a genomic library can be used to hunt for and manipulate any gene from the starting organism.
293
An alternative version of a gene.
Alleles
294
The branch of biology that is the scientific study of inheritance.
Genetics
295
How does the structure of DNA help replication?
The structure of DNA allows it to be precisely replicated because each DNA strand can serve as a mold to guide production of the other strand.
296
What do you call the sugar in DNA and RNA?
The sugar in DNA is deoxyribose; the sugar in RNA is ribose.
297
A relatively unspecialized cell that can give rise to one or more types of specialized cells.
Stem Cells
