Genetics Flashcards
1
Q
What is genetics?
A
Study of heredity
2
Q
unit of heredity
A
genes
3
Q
The father of modern genetics
A
Gregor Mendel
4
Q
Mendel’s Laws of Inheritance
A
- Law of Dominance
- Law of Segregation
- Law of Independent Assortment
5
Q
Laws of Inheritance
Two alleles for a heritable character segregate during gamete formation and end up in different gametes
A
Law of segregation
6
Q
Where did Mendel experimented on that helped him established the Laws of Inheritance?
A
By cross breeding white and purple pea plants and observed the flowers
7
Q
A heritable feature that varies among individuals, such as flower color
A
Character
8
Q
each variant for a character (e.g. purple or white flower)
A
Trait
9
Q
What is the P Generation?
A
Parental generation, true-breeding parents
10
Q
What is the F Generation?
A
Filial generation, hybrids (off-springs of the P generation)
11
Q
T OR F
hybrid offsprings only inherit the dominant trait in the phenotype
A
TRUE
12
Q
What is the ratio of F2 phenotypes?
A
3:1 (dominant allele:recessive allele)
P generation will produce hybrids that inherited the dominant phenotype. But the hybrids (F1) will produce offsprings with the ratio of 3:1. That’s because, the recessive allele never went away but it just did not manifest
13
Q
Alternative versions of a gene
A
Alleles
14
Q
Diagram used to predict the allele composition of offspring from a cross between individuals of known genetic makeup.
A
Punnett Square
15
Q
Breeding an organism of unknown genotype with a recessive homozygote
A
Test cross
16
Q
appearance or observable trait
A
Phenotype
17
Q
genetic make-up of organism
A
Genotype
18
Q
An organism that has a pair of identical alleles for a gene encoding a character is called? and is it said to be? for that gene
A
homozygote, homozygous
19
Q
An organism that has two different alleles for a gene is called a? and is said to be? for that gene
A
heterozygote, heterozygous
20
Q
Two or more genes assort independently. Each pair of alleles segregates independently of each other pair of alleles during gamete formation
A
Law of independent assortment
21
Q
Patterns of inheritance/ Degrees of Dominance
One allele is dominant over the others (e.g. Mendel’s law)
A
Complete dominance
22
Q
Patterns of inheritance/ Degrees of Dominance
Neither allele is completely dominant. F1 hybrids have a phenotype somewhere between those of the two parental varieties
A
Incomplete dominance
23
Q
Patterns of inheritance/ Degrees of Dominance
The two alleles each affect the phenotype in separate, distinguishable ways.
A
Codominance
24
Q
Prediciting inheritance of traits
family tree describing the traits of parents and children across the generations
A
family pedigree
Pedigree analysis
25
# T or F
Pedigree analysis cannot be used to predict disorders that are inherited as those of simple mendelian traits
False
26
Examples of inheritance of autosomal recessive disorder
Albinism, sickle-cell
## Footnote
Albinism - parents are carriers but they themselves carry a normal phenotype (example: both parents have Aa alleles). **Recessive homozygotes**
27
# T or F
A lethal recessive allele can be passed from one generation to the next by heterozygous carriers because the carriers themselves have normal phenotypes.
True
## Footnote
Aa (Mother) and Aa (Dad) = AA, Aa, Aa, aa
aa is the affected child
28
It is caused by the substitution of a single amino acid in the hemoglobin protein of red blood cells
Sickle-cell disease
29
Examples of autosomal dominant disorder
Dwarfism, Huntington's disease
30
# T or F
A lethal dominant allele, often causes the life of afflicted individuals before they can mature and reproduce, so the allele is not passed on to future generations.
False
31
# Transmission fo X-linked recessive traits
Who are affected and what are its examples?
* If the father is affected: It can pass it down to the **daughters only and they will be carriers** (XX, sons will get the Y from their fathers)
* If mother is affected: Can pass it down to a **carrier daughter** and an **affected son**
## Footnote
Hemophilia, color blindness, Duchenne muscular dystrophy
32
# The transmission of Y-linked recessive traits
Who are affected and what are its examples
Sons only, hearing impairment, infertility
33
# T or F
Mitochondrial disorders are only inherited from fathers
False, it is exclusively inherited from mothers
34
This can eliminate some of the uncertainty and allow better predictions of the probabilities and risks involved.
Genetic testing
35
# Testing a fetus for genetic disorders
A sample of amniotic fluid is taken starting at the 15th week of pregnancy
Amniocentesis
36
# Testing a fetus for genetic disorders
Sample of this tissue is taken as early as the 10th week of pregnancy
Chorionic villus sampling (CVS)
37
entire “library” of genetic instructions that an organism inherits
Genome
38
# T or F
Your genome is not your DNA composition
F, it is (and it's made up of ATGC, Adenine, Thymine, Guanine, Cytosine)
39
This project is to determine the complete nucleotide sequence of each chromosomeHow are genome sequenced?
The Human Genome Project (HGP, 1990-2003)
40
How are genome sequenced? (3 stage approach)
Linkage mapping
Physical mapping
DNA sequencing
41
How are genome sequenced? (Whole Genome shotgun approach to genome sequencing)
Cut the DNA into fragments
Clone fragments
Sequence each fragment
Organize sequences
42
How many genes do humans have?
20 000 - 25 000
43
# T or F
Genes work by controlling the production of proteins
True
44
# T or F
Most genes do not contain instructions for building proteins. A few genes contain instructions for building several kinds of RNA that are used in the construction of proteins.
False
45
What experiment led them to knowing that genetic material is DNA and not proteins?
Hershey-chase experiment on virus
## Footnote
When they radiolabelled the proteins of the virus, they found that the infected bacteria did not have any radioactivity. While when they radiolabelled the DNA of the virus, the radioactivity entered the infected bacteria
46
Where does transcription happen?
Nucleus
## Footnote
mRNA is created in the nucleus
47
Where does translation happen?
Ribosome
## Footnote
This is where the RNA gets encoded as proteins
48
# Types of RNA Assist in the Manufacture of Proteins
Specifies the order of amino acids in a protein using a series of three-base codons
Messenger RNA (mRNA)
49
# Types of RNA Assist in the Manufacture of Proteins
Major component of ribosomes, assists in making **covalent bonds** link amino acids together to make a protein
Ribosomal RNA (rRNA)
50
Transports correct amino acid to the ribosome using the information encoded in the mRNA, contains a three-base anticodon that pairs with a complementary codon revealed in the mRNA
Transfer RNA (tRNA)
51
the process by which DNA directs the synthesis of proteins
Gene expression
52
transfer of sequential information deals with the detailed residue-by-residue . It states that such information cannot be transferred back from protein to either protein or nucleic acid.
Central Dogma
53
# Structural and functional organization of DNA
most codes for proteins used by the organisms; others code for tRNAs, rRNAs and other small RNAs that help regulate gene expression
Exons (of genes)
## Footnote
nasa dulo siya ng genes
54
# Noncoding DNA
sequences of noncoding DNA found within a gene that are removed from mRNA after transcription
Introns
55
# Noncoding DNA
sequence of noncoding DNA that separate the genes
Spacer DNA
56
sequences of DNA that can move from one position on chromosome to another, or from one chromosome to another
Transposons (jumping genes)
## Footnote
The color patterns in corncobs were caused by the activity of transposons that inserted themselves into pigment genes.
57
# T or F
Different cell type express different genes. Some genes are active (“on”) only in the types of cells that use or produce the protein encoded by the gene
True
58
genes that are active in most type of cells
"Housekeeping" genes
59
Eukaryotes control gene expression in development through [---], which are regulated by [---] (master-switch) genes.
gene cascades, homeotic
60
What is SNP
Single Nucleotide Polymorphism (SNP, pronounced SNIP)
61
a single base-pair site in your genome where variation is found
SNP
## Footnote
They are used as genetic markers for disease-causing alleles.
62
How do we find and analyze SNPs?
* RT-PCR Analysis of the Expression of Single Genes
* DNA Microarray Assay of Gene Expression Levels
63
# How do we find and analyze SNPs?
It uses the enzyme reverse transcriptase (RT) in combination with PCR and gel electrophoresis. can be used to compare gene expression between samples—for instance, in different embryonic stages, in different tissues, or in the same type of cell under different conditions.
RT-PCR Analysis of the Expression of Single Genes
## Footnote
Reverse Transcription - Polymerase Chain Reaction
64
# How do we find and analyze SNPs?
test genes simultaneously to determine which ones are expressed in a particular tissue, under different environmental conditions, in various dis- ease states, or at different developmental stages
DNA Microarray Assay of Gene Expression Levels
65
set of techniques that scientists use to manipulate DNA directly
DNA technology
66
# T or F
DNA structure is not the same in all organisms; basic techniques do not work on all species.
False
67
Where is DNA technology used?
* DNA sequencing and synthesis
* Gene/DNA cloning for gene expression studies
* Genetic screening
* DNA Fingerprinting: Catching the bad guys using DNA
* DNA profiling: Finding your family
* Cloning
* Genetic engineering: Transgenic organisms
* Editing genes and genomes
68
Determining the sequence of bases in a DNA fragment, a gene, or even the entire genome of organisms.
## Footnote
This rely on automated sequencing machines which are able to identify over a million bases per day. DNA can also be sequenced manually by relatively slow but also highly effective methods.
DNA sequencing and synthesis
69
Methods of DNA Sequencing and what are they?
* **Sanger method/Chain termination method** - dideoxyribonucleotide (or dideoxy) chain termination sequencing. The method was developed by two time Nobel Laureate Frederick Sanger and his colleagues in 1977, hence the name the Sanger Sequence
* **Next generation sequencing** – Sequencing by synthesis
* **Third generation sequencing**
70
Making Multiple Copies of a Gene or Other DNA Segment
Gene/DNA cloning for gene expression studies
71
small, circular DNA molecules that are replicated separately (found in bacteria)
Plasmids
72
# T or F
A gene is said to be cloned if it has been isolated and many copies of it have been made
True
73
How many base pairs do humans have on 23 chromosomes?
3.3 billion, each containing 140 million base pairs
74
# Key enzymes
connect two DNA fragments to each other, making it possible to insert a gene from one organisms to DNA of another
Ligases
75
# Key enzymes
the key enzyme involved in DNA replication, can also be used by geneticists to make many copies of a gene or other DNA sequence in a test tube
DNA polymerase
76
# Key enzymes
cut DNA at specific places
Restriction enzymes
77
DNA fragments move through a gel at different rates, based on size.
Gel electrophoresis
## Footnote
Fragments towards + end of the gel are shorter than fragments found toward the - end
78
primers (*short segments of DNA that can bind to the beginning and end of the gene) are synthesized and used to produce billions of copies of the gene
Polymerase chain reaction (PCR)
79
When exposed to several single-stranded segments of test DNA, a DNA probe can bind only to the segment that contains the base sequence that is complimentary to the probe.
DNA Hybridization
## Footnote
can be used to test whether a person has copies of mutant alleles that cause a disease
80
ethod used to identify an individual from a sample of DNA by looking at unique patterns in their DNA. Comparing DNA bands pattern between different individuals in blood or other tissues
DNA Fingerprinting: Catching the bad guys using DNA
81
# Cloning
Replication of good phenotypes of organisms (plants and animals)
Reproductive cloning
82
# Cloning
Treatments of disease
Therapeutic cloning
83
# T or F
Transgenic organisms contains gene from other species. They are also called GMO’s – Genetically modified organisms
True
## Footnote
The genetic code is universal, therefore it is possible to make transgenic organisms
84
a bacterial protein that helps defend bacteria against bacteriophage infections in a system
Cas9
85
# T or F
In bacterial cells, Cas9 acts together with a “guide RNA” made from the CRISPR region of the bacterial system
True
86
mutations are introduced into a cloned gene. Mutated gene is returned to a cell in such a way that it disables (“knocks out”) the normal cellular copies of the same gene.
in vitro mutagenesis
