Ujjj Flashcards
(129 cards)
1
Q
What is genetics?
A
The scientific study of inherited traits and their variation
Genetics deals with the study of genes, heredity, and genetic variation.
2
Q
What is the etymology of the term ‘genetics’?
A
Derived from Genetikos meaning ‘generative’; related to Genesis meaning ‘beginning’ or ‘origin’
Coined by William Bateson.
3
Q
What is heredity?
A
The transmission of traits from parents to offspring or between generations.
4
Q
What are genes?
A
Segments or sections of DNA that contain instructions to make proteins.
5
Q
Who is known as the ‘Father of Genetics’?
A
Gregor Mendel.
6
Q
What did Gregor Mendel study?
A
The inheritance of traits in pea plants.
7
Q
What are the laws of inheritance developed by Mendel?
A
Law of Segregation and Law of Independent Assortment.
8
Q
What is the Law of Segregation?
A
Inherited units are independently segregated.
9
Q
What is the Law of Independent Assortment?
A
Inherited units assort independently during gamete formation.
10
Q
What did Friedrich Miescher discover?
A
DNA as a weak acid within chromosomes.
11
Q
What is the chromosomal theory of inheritance?
A
The theory that genes are located on chromosomes.
Introduced by William Henry Sutton and Theodor Boveri.
12
Q
What is transformation in genetics?
A
The change in genotype and phenotype due to the incorporation of external DNA by a cell.
13
Q
Who demonstrated that DNA was the transforming substance?
A
Oswald Avery.
14
Q
What conclusion did Hershey and Chase reach regarding DNA?
A
DNA is responsible for the transformation of bacteria, not proteins.
15
Q
What is Chargaff’s Rule?
A
DNA composition varies between different species, and the four nitrogen bases are present in a predictable ratio within a species.
16
Q
What structure did Watson and Crick propose for DNA?
A
The double helix structure.
17
Q
What is the central dogma of molecular biology?
A
DNA → RNA → protein.
18
Q
What is a chromosome?
A
A double stranded DNA molecule packaged by histone and scaffold proteins.
19
Q
What is the haploid number represented as?
A
n.
20
Q
What is the diploid number represented as?
A
2n.
21
Q
What are homologous chromosomes?
A
Chromosomes that share centromere position, overall size, and contain identical gene sets at matching positions (loci).
22
Q
What is an allele?
A
A variation in DNA sequence at a locus.
23
Q
What are the three major types of RNA?
A
- rRNA
- tRNA
- mRNA
24
Q
What is a genotype?
A
Set of alleles present in the genome of an organism.
25
What is a phenotype?
The result of gene expression.
26
What are the major fields of genetics?
* Cytogenetics
* Molecular Genetics
* Classical Genetics
* Population Genetics
* Behavioral Genetics
27
What does transmission genetics examine?
Patterns of inheritance of traits based on Mendel's experiments.
28
What is the role of cytogenetics?
Study of chromosomes and their structure through light microscopy.
29
What is molecular genetic analysis?
Determining the precise nucleotide sequence of genes.
30
What is population genetics focused on?
Understanding how genetic variation is maintained in populations over time.
31
What are some applications of genetics in medicine?
* Synthetic hormones
* Drugs
* Vaccines
32
What is DNA fingerprinting used for?
Solving paternity cases and crimes.
33
What are the components of the endomembrane system?
* Endoplasmic reticulum
* Golgi apparatus
* Lysosomes
34
What is the primary difference between prokaryotic and eukaryotic cells?
Prokaryotic cells lack a membrane-bound nucleus.
35
What are two domains of prokaryotic cells?
* Archaea
* Bacteria
36
What are the two domains of prokaryotic cells?
Archaea and Bacteria
37
What distinguishes eukaryotic cells from prokaryotic cells?
Eukaryotic cells contain specialized organelles and a membrane-bound nucleus
38
What is the function of the cytoskeleton?
Maintains cell shape
39
What is the endomembrane system composed of?
* Endoplasmic reticulum
* Golgi apparatus
* Lysosomes
40
What is the structure of biological membranes?
A double layer of phospholipids
41
What are plant cell walls made of?
Cellulose fibers embedded in other polysaccharides and protein
42
What is the function of the nucleus?
Contains the cell's genetic information
43
What is the role of ribosomes in cells?
Carry out protein synthesis
44
What are the two types of endoplasmic reticulum?
* Rough ER
* Smooth ER
45
How does the Golgi apparatus modify proteins?
Sorts and packages proteins and lipids in vesicles
46
What is pulse-labeling used for?
Observation of the secretory pathway
47
What is the function of lysosomes?
Digest macromolecules and cell parts
48
What do peroxisomes do?
Break down long-chain fatty acids
49
What is a central vacuole?
Found in plants, contains watery sap and maintains turgor pressure
50
What is the function of chloroplasts?
Capture solar energy and produce carbohydrates
51
What is the main function of mitochondria?
Break down carbohydrates and produce ATP
52
What do cilia and flagella contain?
Microtubules
53
What is the function of the centrosome?
Microtubule-organizing center
54
What are the three types of junctions found in animal cells?
* Anchoring junctions
* Tight junctions
* Gap junctions
55
What is the significance of somatic cells?
Make up most of the organism and undergo mitosis
56
What is the difference between diploid and haploid cells?
Diploid (2n) has two chromosomes of each kind; haploid (n) has one chromosome of each kind
57
What is cancer in relation to cell division?
Uncontrolled cell division
58
What are telomeres?
Repeating DNA base sequences at the ends of chromosomes
59
How does crossing-over occur during meiosis?
Nonsister chromatids exchange genetic material
60
What is a karyotype?
Picture of chromosomes in numbered pairs called homologous chromosomes
61
What is the result of nondisjunction?
Abnormal chromosome numbers
62
What is trisomy 21 commonly known as?
Down Syndrome
63
What are the characteristics of cancer cells?
* Lack differentiation
* Have abnormal nuclei
* Form tumors
* Metastasis
* Angiogenesis
64
What dietary guidelines can help reduce cancer risk?
* Increase consumption of foods rich in vitamins A and C
* Limit salt-cured, smoked, or nitrite-cured foods
* Include vegetables from the cabbage family
* Be moderate in alcohol consumption
* Maintain a healthy weight
65
Who is Gregor Johann Mendel?
He laid the foundation of modern genetics
66
What did Mendel's laws apply to?
All sexually reproducing organisms
67
What is the significance of observable variation in Mendel's work?
Essential for following genes
68
Fill in the blank: Mitosis conserves the number of chromosome sets, producing cells that are genetically _______ to the parent cell.
identical
69
Fill in the blank: Meiosis reduces the number of chromosomes sets from _______ (diploid) to _______ (haploid).
two, one
70
What is the first definition of a gene based on Mendel's observations?
A gene is a hereditary character that is inherited unchanged
71
What is a character in genetic vocabulary?
A heritable feature, such as flower color
72
What is a trait?
A variant of a character, such as purple or white flowers
73
What are alleles?
Alternative forms of traits
74
Define phenotype
Observable characteristic of an organism
75
Define genotype
Pair of alleles present in an individual
76
What does homozygous mean?
Two alleles of a trait are the same (YY or yy)
77
What does heterozygous mean?
Two alleles of a trait are different (Yy)
78
What is the P generation?
Parental generation
79
What is the F1 generation?
1st filial generation, progeny of the P generation
80
What is the F2 generation?
2nd filial generation, progeny of the F1 generation
81
What is a monohybrid cross?
Cross of two different true-breeding strains that differ in a single trait
82
What is a dihybrid cross?
Cross of two different true-breeding strains that differ in two traits
83
What was a key observation from Mendel's cross of white and purple flowered pea plants?
All of the offspring were purple
84
What ratio of purple to white flowers was observed in the F2 generation?
About 3:1
85
What is the law of segregation?
The two alleles for a heritable character separate during gamete formation
86
What does a testcross allow us to determine?
The genotype of an organism with a dominant phenotype but unknown genotype
87
What is the expected phenotypic ratio for the F2 generation in a dihybrid cross?
9:3:3:1
88
What does Mendel's law of independent assortment state?
When gametes form, each pair of hereditary factors segregates independently of the other pairs
89
What is incomplete dominance?
Neither allele is dominant and heterozygous individuals have an intermediate phenotype
90
What is codominance?
Neither allele is dominant and both alleles are expressed in heterozygous individuals
91
What are polygenic traits?
Traits controlled by the combined interaction of many gene loci
92
What is epistasis?
A type of polygenic inheritance where alleles at one gene locus can hide or prevent the expression of alleles at a second gene locus
93
What is pleiotropy?
A single gene locus affects more than one trait
94
What is a pedigree?
A graphic representation of how a trait is passed from parents to offspring
95
What is the difference between autosomal and sex-linked inheritance?
Autosomal is inherited on chromosomes 1-22, while sex-linked is inherited on X or Y chromosomes
96
What is an example of an autosomal dominant condition?
Huntington's Disease
97
What is an example of an autosomal recessive condition?
Cystic fibrosis
98
What is an example of an X-linked recessive condition?
Hemophilia
99
What is the expected phenotype ratio in a monohybrid cross?
3:1
100
In Mendel's experiments, what did the purple flower color signify?
It was the dominant trait
101
Fill in the blank: Alleles for different traits assort ________ of one another.
independently
102
True or False: Mendel's laws apply only to plants.
False
103
What is the role of statistical analyses in Mendel's experiments?
To work with large numbers of plants, count all offspring, and make predictions
104
What does the multiplication rule of probability state?
The probability that two or more independent events will occur together is the product of their individual probabilities
105
What does the addition rule of probability state?
The probability that any one of two or more exclusive events will occur is the sum of their individual probabilities
106
What type of inheritance pattern do autosomal dominant traits follow?
Traits appear in every generation.
107
Give an example of an autosomal dominant disease.
Achondroplasia.
108
What is a key characteristic of autosomal recessive traits in pedigrees?
Trait often skips generations.
109
How does the trait distribution of autosomal recessive traits compare between sexes?
Affects males and females equally.
110
List possible diseases that are autosomal recessive.
* Cystic fibrosis
* Sickle cell anemia
* Phenylketonuria (PKU)
* Tay-Sachs disease
111
What is a defining feature of X-linked dominant diseases?
Often lethal in males before birth.
112
Provide an example of an X-linked dominant disease.
Incontinentia pigmenti.
113
What is a key characteristic of X-linked recessive traits?
Affected fathers do not pass the trait to their sons.
114
Which sex is more often affected by X-linked recessive traits?
Males.
115
What is an example of an X-linked recessive disorder?
Glucose-6-Phosphate Dehydrogenase deficiency.
116
What is the inheritance pattern of Y-linked traits?
Only males are affected.
117
What is an example of a Y-linked trait?
Hairy ears.
118
What type of inheritance does Marfan's Syndrome exhibit?
Autosomal dominant.
119
What are the genotype codes for normal individuals in Marfan's Syndrome?
Code 'm' for recessive normal allele, 'M' for dominant allele.
120
What is required for an individual to be affected by Marfan's Syndrome?
Must have at least one 'M' allele.
121
What does albinism demonstrate in terms of inheritance?
Autosomal recessive.
122
What is the genotype for affected individuals with albinism?
Homozygous for 'a'.
123
What are the genotype codes for albinism?
Code 'A' for dominant normal allele, 'a' for recessive allele.
124
What must normal individuals have at least one of in albinism?
One 'A' allele.
125
How is hemophilia inherited?
X-linked recessive.
126
What is the genotype code for the hemophilia allele?
Code 'h' for recessive allele.
127
Who passes the hemophilia allele to daughters?
Affected fathers.
128
What is the purpose of pedigrees in genetics?
To determine the probability of a child having a disorder.
129
What must be determined to interpret a pedigree?
If the disease is autosomal or X-linked and dominant or recessive.
