Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Biology > Genetics > Flashcards

Genetics Flashcards

You may prefer our related Brainscape-certified flashcards:
AP® Biology flashcards Biology 101 flashcards
1
Q

Gene

A

the basic unit of heredity. Composed of DNA and are located on chromosomes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Alleles

A

When a gene exists in more than one form, the alternate forms is called alleles.
An organism has two alleles for each trait. one from each parent

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Genotype

A

an individuals genetic makeup

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Phenotype

A

Physical manifestation of a individuals genetic make up

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Mendelian Genetics

A

in 1860s Gregor Mendel developed the basic principles of genetics with the garden pea.
Created Law of Segregation, Law of Independent assortment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

True breeding

A

which if self crossed produce progeny only with the parental phenotype

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Law of segregation

A

two alleles segregate during meiosis, resulting in gametes that carry only one allele for any given trait.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Mendel’s Law of dominance

A

If two alleles in an organism are different only one will be fully expressed and the other will be silent. The expressed allele is dominant. The silent is recessive.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Homozygous

A

organisms that contain two copies of the same allele

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Heterozygous

A

organisms that carry two different alleles. The dominant allele appears in the phenotype

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Monohybrid Cross

A

only one trait is being studied in a mating.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

P generation

A

Parental generation being mated will be homozygous for each allele

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

F generation

A

filial generation is the progeny being created from the P generation. each generation is numbered sequentially

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Punnett square diagram

A

one way of predicting possible genotypes expected from a cross. indicates all the potential progeny genotypes and relative frequencies.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Test cross/ back cross

A

only with a recessive phenotype can genotype be predicted with 100% accuracy. Due to it must be homozygous. an organism with a dominant phenotype of unknown genotype (Ax) is crossed with a phenotypically recessive organism (aa). The progeny will dictate if the dominant phenotype is heterozygous or homozygous.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Dihybrid cross

A

the parents differ in two traits. as long as the genes are independently assorted during meiosis and on separate chromosomes.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Mendel’s Law of independent assortment

A

the pattern of traits being transmitted to offspring independently.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Mendelian F2 phenotype ratio of dihybrid self crossed F1

A

9:3:3:1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Incomplete dominance

A

when the phenotype of the heterozygote is an intermediate of the phenotypes of the homozygotes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Codominance

A

occurs when multiple alleles exist for a given gene and more than one of them are dominant. Each dominant allele is fully dominant when with a recessive but when two dominant alleles are present, the phenotype result of the expression of both dominant alleles simultaneously

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Sex Determination

A

in sexually differentiated species , most chromosmes exist as pairs of homolouges called autosomes, but sex is determined by a pair of sex chromosomes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

locus

A

the location on a chromosome where a gene is located

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Epistasis

A

occurs when one gene affects the phenotypic expression of a second gene. For example pigmentation, one gene will determine if it will or will not be seen while another determines what color will be seen.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Pleiotropy

A

occurs when a single gene has more than one phenotypic expression.Example the pea plant that is round or wrinkled also determines what kind of absorbtion they have. Many disease- causing genes exhibit pleiotropy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Polygenic Inheritance

A

the interaction of many genes to shape a single pheonotype. Leads to continuous variation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Linked genes

A

genes that reside on the same chromosome and thus cannot segregate independently becuase they are physically connected. Genes that are linked are normally inhereted together.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Linkage map

A

a chromosome map created by using the percentages of the cross over frequency. The freateer the distance between two genes on a chormosome the more places the gene can break and more likely the two genes will cross over during synapsis.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

sex linked genes

A

genes that reside on the X or Y chromosome. Majority are X linked but Y is possible. most of these genes are phenotypically expressed in males. due to they only have one X chromosome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

X-inactivation

A

during embryonic development in female mammals one of the two X chromosomes in each cell does not uncoil into chromatin. so X inactivation occurs and one chromosome remains coiled as a dark compact body called a Barr body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Barr body

A

Barr bodies are mostly inactive X chromosomes- most the genes are not expressed nor do they interact with their respective alleles.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Nondisjunction

A

the failure of one or more chromosome pairs or chromatids of a single chromosome to properly seperate during meiosis or mitosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Failure for two homologus chromosomes during anaphase I or II in meiosis is

A

non disjuction that leads to gametes with extra or missing chromosomes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Mosaicism

A

During mitosis the failure of two chromatids of a single chromosome (during anaphase) to seperate and segregate produces daughter cells with extra or missing chromosomes. Occurs during embryonic development where a fraction of the body cells are efffected

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Polypliody

A

occurs if all of the chromosomes undergo meiotic non disjunction and produce gamets with twice the number of chromosomes. common in plants

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Point mutations

A

occur when a single nucleotide in the DNA of a gene is incorrect. can be caused by substitution, insertion or deletion.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Substitution

A

nucleotide is substituted for the correct one

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

deletion

A

if a nucleotide base pair is omitted

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

insertion

A

if an extra base pair is inserted

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

Aneuploidy

A

a genome with extra or missing chromosomes. Often caused by nondisjunction. Most are aneuploid gametes are sterile but some survive. examples are down syndrome and turner syndrome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

Down syndrome

A

Trisomy 21. occurs when an egg or sperm with an extra number of 21 chromosome fuses with a normal gamete. these individuals bear various abnormalities

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

Turner syndrom

A

results when there is a nondisjunction of sex chromosomes. Sperm will either have both XY or none (O) same for eggs (XX or O). These individuals are physically abnormal and sterile

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

Chromosomal abberations

A

caused when chromosome segments are changed such as duplications, inversions or translocations

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

Duplications

A

when a chromosome segment is repeated on the same chromosome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

Inversions

A

occur when a chromosome segments are rearranged in reverse oreintation on the same chromosome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

Translocations

A

when a segment of a chromosome is moved to another chromosome. Example is down syndrome occuring when segment of 21 to chromosome 14. has the same phenotypic effect of trisomy 21

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

Nucleotides

A

constists of three parts, nitrogen base, sugar and phosphate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

DNA

A

deoxyribose sugar, Nitrogen bases are adenine, thymine, guanine and cytosine and has a double helix structure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

RNA

A

ribose sugar, nitrogen bases are adenine uracil, guanine and cytosine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

mRNA

A

provides the instructions for assembling amino acids into the polypeptide chain, Has a liner structure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

tRNA

A

delivers amino acids to a ribosome for their addition into a growing peptide chain. shape is clover-leafed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

rRNA

A

combines with proteins to form ribosomes. shape is globular

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

DNA replication

A

occurs during interphase of the cell cycle and involves seperating (unzipping) the DNA molecule into two strands, each of which serves as a template to assemble a new strand. The result is two identical strands

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

Semiconservative replication

A

when each of the double stranded molecules of DNA consists of a single strand of old DNA and a new complementary strand.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

helicase

A

an enzyme that unwinds the DNA helix during DNA replication

55
Q

Replication fork

A

formed from the unzipping of DNA strands.

56
Q

Single- strand binding protiens

A

used to attach to each strand of uncoiled DNA to keep them seperate.

57
Q

Topoisomerases

A

break and rejoin the double helix, allowing the twists to unravel and preventing the formations of knots, following the helicase

58
Q

anti parallel

A

the DNA polymerase moves in the 3’-5’ direction along each template strand. The new strand grows in the anti parallel 5’-3’ direction.

59
Q

Leading strand

A

for the 3’-5’ template strand replication occurs continusouly as the DNA polymerase follows the replication fork, assmebling a 5’-3’ leading strand.

60
Q

Okazaki segments

A

short segments of complementary DNA. For the 5-3’ template strand, the DNA polymerase moves away from the replication fork. this is because it can assemble nucleotides only in 3-5’ direction. so it has to make these short segments and then return back to the replication fork.

61
Q

DNA ligase

A

what is used to connect the Okazaki segments producing a single complement strand

62
Q

lagging strand

A

the strand that is produced from the 5’-3’ templete strand, hence its name because it takes longer to assemble than the leading strand

63
Q

Primase

A

enzyme that begins replication with a short segment of RNA nucleotides, called the RNA Primer.

64
Q

RNA Primer purpose

A

the leading strand and every Okazaki segment on the lagging strand must begin with an RNA primer so that DNA polymerase can attach succeding DNA nucletotides

65
Q

Where does energy from elongation come from

A

DNA elongation energy is provided by two additional phosphates that are attached to each new nucleotide. Breaking the bonds holding the two extra phosphates provides chemical energy

66
Q

telomeres

A

ends of eukaryotic chromosomes

67
Q

telomerase

A

enzyme that attaches to the end of the templete strand and extends the templete strand by adding a short sequence of DNA nucleotides over and over again. This allows the elongation of the lagging strand to continue until completetion

68
Q

trait

A

the end product of metabolic processes regulated by enzymes

69
Q

protein synthesis

A

the process that describes how enzymes and other proteins are made from DNA

70
Q

Steps of protein synthesis

A

transcription, RNA processing and tranlation. In transcription RNA molecules are created by using the DNA molecule as a template. After, RNA processing modifeis the RNA molecule with deletions and additions. In translation, the processed RNA molecules are used to assemble amino acids into a polypeptide.

71
Q

Messenger RNA

A

mRNA single strand of RNA that provides the template used for sequencing amino acids into a polypeptide.

72
Q

codon

A

a triplet group of three adjacent nucleotides on the mRNA that codes for one specific amino acid

73
Q

Genetic code

A

provides the deconding for each codon

74
Q

transfer RNA

A

a short RNA molecule (consisting of about 80 nucleotides) that is used for transporting amino acids to their proper place on the mRNA template

75
Q

anticodon

A

another portion of the RNA specified by a triplet combination of nucleotides. during translation, The anticodnon of the tRNA base pairs with the codon of the mRNA

76
Q

ribosomal RNA

A

these molecules are the building blocks of ribosomes.

77
Q

Transcription

A

begins with initiation, elongation and ends with termination

78
Q

Initiation

A

the RNA polymerase attaches to a promoter region on the DNA and begins to unzip the DNA into two strands. A promoter reigon for RNA transcriptions often contains the sequence TATA

79
Q

Elongation

A

occurs as the RNA polymerase unzips the DNA and assembles RNA nucleotides using one strand of DNA as the template. Occurs in 5’-3’ direction. only one strand DNA strand is used

80
Q

Termination

A

occurs when the RNA polymerase reaches a specail sequence of nucleotides that serve as a termination point. often contains the DNA sequence AAAAA

81
Q

mRNA processing

A

before an mRNA leaves the nucleus it undergoes the following alterations.

1) 5’ cap is addes to the 5’ end of the mRNA
2) a poly- A tail is attached to the 3’ end of the mRNA
3) RNA splicing
4) alternative splicing

82
Q

5’ cap

A

a gaunine nucleotide with two additional phosphate groups, forming GTP. capping provides stability to the mRNA and a point of attachment for the small sub unit of ribosome

83
Q

poly-A tail

A

The tail consists of about 200 adenine nucleotides. it provides stability to the mRNA and also appears to control the movement of the mRNA across the nuclear envelope

84
Q

RNA splicing

A

removes nucleotide segments from mRNA. before mRNA moves to the cytoplasm small nuclear ribonucleoproteins delete introns and splice the exons.

85
Q

exons

A

sequences that express a code for a polypeptide

86
Q

introns

A

intervening sequences that are non coding

87
Q

alternative splicing

A

allows different mRNA;s to be generated fro the same RNA transcript. by selectively removing different parts of an RNA transcript, different mRNA’s can be produced.

88
Q

Translation

A

GTP acts as an energy supplier for this event to take place.

1) Initiation begins when the small ribosomal subunit attaches to a special region near the 5’ end of the mRNA
2) Elongation begins as tRNA binds to the A site of the ribosome delivering amino acids. it then moves from the A site to the P site.
3) termination occurs when the ribosome encounters one of the three stop codons. At termination, the completed polypeptide, the last tRNA and the two ribosomal subunits are released.

89
Q

Mutations

A

any sequence of nucleotides in a DNA molecule that does not exactly match the original DNA molecule from which it was copied.

90
Q

Point mutation

A

a single nucleotide error and includes:

substitution, deletion, insertion or frame shift

91
Q

Frameshift

A

mutation occurs when a nucleotide is deleted or inserted. causing all subsequent nucleotides to be displaced one position.

92
Q

Silent mutation

A

occurs when the new codon still codes for the same amino acid

93
Q

Missense mutation

A

occurs when the new codon codes for a new amino acid

94
Q

nonsense mutation

A

occurs when the new codon codes for a stop codon

95
Q

Mutagens

A

radiation or chemicals that can cause mutations

96
Q

Carcinogens

A

are mutagens that activate uncontrolled cell growth (cancer)

97
Q

Proofreading

A

DNA polymerase checks to make sure that each newly added nucleotide correclty base pairs with a template strand. if not it is removed and replaced correctly

98
Q

Mismatch repair

A

enzymes repair error that escape the proof reading ability of DNA polymerase

99
Q

Excision repair

A

enzymes remove nucletotides damaged by mutagens. the enzymes identify which of the two strands of the DNA contain a damaged nucleotide and hten use the complementrary strand as a template to repair.

100
Q

Chromatin

A

in eukaryotes DNA is packaged with protiens and form this matrix

101
Q

nucleosomes

A

DNA that is coiled around bundles of histone proteins to form DNA-histone complexes

102
Q

Euchromatin

A

describes the reigons where DNA is loosely bound to nucleosomes. DNA in these regions is actively being transcribed

103
Q

Heterochromatin

A

represents areas where the nucleosomes are more tightly compacted and where DNA is inactive. stains darker than euchromatin

104
Q

transposons

A

jumping genes, can move to a new location on the same chromosome or to a different chromosome. They may change the expression of a gene or turn on or off its expression or have no effect

105
Q

bacteriophages

A

viruses that only attack bacteria

106
Q

Virus structure

A
  • a nucleic acid (either RNA or DNA) contains the hereditary info. Can be double or single stranded
  • capsid or protein coat encloses the nucleic acid
  • envelope surrounds the capsid of some viruses. incorporating phospholipids and proteins obtained from the cell membrane of the host
107
Q

capsomeres

A

assemble to form the capsid

108
Q

Lytic cycle

A

a virus penetrates the cell membrane of the host and uses the enzyme of the host to produce viral nucleic acids and viral proteins. They then assmeble into new viruses and erupt from the host cell, destroying the cell in the process.

109
Q

Retroviruses

A

are ssRNA viruses that use an enzyme called reverse transcriptase to make DNA complement of the RNA. then the DNA can be used to create another lysogenic cycle

110
Q

Lysogenic

A

the viral DNA is temporarily incorporated into the DNA of the host cell lying dormant as a provirus or prophage. Until stimulated then goes into lytic cycle

111
Q

binary fission

A

the chromosome replicates and the cell divides into two cells one chromosome in each .

112
Q

plasmids

A

short circular DNA molecules outside the chromosome. carry genes that are beneficial but not normally needed for survival .

113
Q

episomes

A

plasmids that can become incorporated into the chromosomes.

114
Q

Conjugation

A

a process of DNA exchange between bacteria. A donor bacterium produces a tube or pilus that connect to a recipient bacterium. Through the pilus the donor sends chromosomal or plasmid DNA.

115
Q

F plasmid

A

contains the genes that enable a baceterim to produce pili, when a recipient receives F it then can do the same. F+ and F-

116
Q

R plasmids

A

provide bacteria with resistance against anitbodies

117
Q

transduction

A

occurs when new DNA is introduced into the genome of a bacteria by a virus.

118
Q

transformation

A

occurs when bacteria absorb DNA from their surroundings and incorporate it into their genome. specialized proteins on the cell membranes facilitate this

119
Q

operon

A

in prokaryotes is a unit of DNA that controls the transcription of a gene. it contains a promoter, operator, structural gene, and regulatory gene

120
Q

promoter of operon

A

a region that is a sequence of DNA to which the RNA polymerase attaches to begin transcription

121
Q

operator of operon

A

region that blocks the action of RNA polymerase if this region is occupied by a repressor protein.

122
Q

structural genes of operon

A

contain DNA sequences that code for several related enzymes that direct production of some particular end

123
Q

regulatory gene

A

lying outside the operon region produces repressor proteins

124
Q

lac operon

A

in E.coli contols the breakdown of lactose. induced by lactose. therefore the enzymes that it produces are inducible enzymes

125
Q

trp operon

A

in E.coli produces enzymes for the synthesis of the amino acid tryptophan. Here tryptophan is a corepressor. these are repressible enzymes

126
Q

Regulatory proteins

A

repressors and activators operate similarly to those in prokaryotes. influencing how readily RNA polymerase will attach to a promoter region. in many cases, numerous activators are acting in concert to influence transcription.

127
Q

nucleosome packing

A

influences whether a section of DNA will be transcribed. DNA is tightly packed by methylation of histones, making transcription more difficult.

128
Q

acetylation

A

addition of acetyl groups will break down histones and allow for the uncoiling and transcription of specific DNA regions

129
Q

RNA interference

A

occurs when interfering RNAs block mRNA transcription or translation or degrade existing mRNA.

130
Q

Recombinant DNA

A

contains DNA segments or genes from different sources. DNA transferred from one part to another.
can occur naturally through viral transduction, bacterial conjugation transposons or technology

131
Q

Recombinant DNA technology

A

uses restriction enzymes to cut up DNA. they are very specific and cut at specific places. manufactured from bacteria that produce these enzymes to combat virus

132
Q

gel electrophroesis

A

DNA fragments of different lengths are separated as they diffuse through a gelatinous material under the influence of an electrical field. often used to compare DNA fragments of closely related species

133
Q

DNA fingerprinting

A

RFLPs produced from DNA is left on an object are compared to the DNA of an individuals RFLP. used in crime scenes

134
Q

polymerase chain reactions

A

uses synthetic primers that initiate replication at a specific nucleotide sequence.

Biology (17 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions