GENETICS Flashcards
(82 cards)
1
Q
a
foundational concept that describes the
directional flow of genetic information within a
biological system.
A
Central Dogma of Molecular Biology
2
Q
Central Dogma was first proposed by _____ _____ in ______.
A
Francis Crick
1958
3
Q
outlines how genetic
instructions stored in DNA are ultimately used
to produce functional proteins.
A
Central Dogma
4
Q
The Central Dogma states that genetic
information flows from ____ → ____ → ________.
A
DNA
RNA
Protein
5
Q
3 major processes of central dogma
A
- Replication
- Transcription
- Translation
6
Q
This sequence ensures that the hereditary
code in DNA is expressed as the proteins that
perform _______, ________, and _________
functions in the cell.
A
structural
catalytic
regulatory
7
Q
The process by which DNA is copied before cell division.
A
DNA Replication
8
Q
In DNA Replication, the DNA is being ______ before cell division.
A
copied
9
Q
key enzymes of DNA Replication
A
- Helicase
- DNA polymerase
- Primase
- Ligase
10
Q
- unwinds (unzips) the DNA double helix
A
Helicase
11
Q
- synthesizes new strands in a 5’ to 3’ direction
- builds the new DNA strand by adding new DNA bases (A,T,C,G) to the primer
A
DNA polymerase
12
Q
- lays RNA primers (small piece of RNA) to show where DNA replication should start
A
Primase
13
Q
- seals gaps between Okazaki fragments on the lagging strand
- joins or “glues” DNA fragments together
A
Ligase
14
Q
small pieces of DNA made on the lagging strand (the strand going in the opposite direction)
A
Okazaki fragments
15
Q
each new DNA molecule contains one old and one new strand
A
semiconservative model
16
Q
DNA is transcribed into messenger RNA (mRNA)
A
Transcription
17
Q
steps in transcription
A
- initiation
- elongation
- termination
18
Q
- RNA polymerase binds to the promoter region
- RNA polymerase finds the start point on the DNA (called the promoter) and binds to it.
A
Initiation
19
Q
- RNA polymerase synthesizes RNA using the template strand
- RNA polymerase moves along the DNA and adds RNA bases (A,U,C,G) to build the RN strand
A
Elongation
20
Q
- RNA polymerase releases when it hits a termination sequence
- RNA polymerase reaches a stop signal on the DNA, and the process ends.
A
Termination
21
Q
Only ___ DNA strand is used as a template
A
one
22
Q
In eukaryotes, pre-mRNA undergoes _____, _________, and __________.
A
splicing
5’ capping
poly-A tailing
23
Q
mRNA is translated into a polypeptide chain (protein)
A
Translation
24
Q
location of translation
A
cytoplasm (ribosomes)
25
players in translation
- mRNA
- tRNA
- ribosomes
26
carries amino acids and matches codons via its anticodon
tRNA
27
facilitate peptide bond formation
ribosomes
28
Gene regulation plays a critical role in _______ ___
____________- during the development of
multicellular organisms, ensuring that different
cell types express the __________ _____.
guiding cell differentation
appropriate genes
29
carries the codon sequence
mRNA
30
enables organisms to respond
to environmental changes by turning genes
on or off inreaction to external stimuli.
Gene regulation
31
allows cells to conserve
energy and resources by only producing
proteins when they are needed.
Gene regulation
32
Prokaryotic gene operation
- Lac Operon
- Trp Operon
33
controlled by presence of lactose
Lac Operon (inducible) – E. coli
34
- controlled by levels of tryptophan
Trp Operon (repressible) – E. coli
35
Lac Operon includes:
- promoter
- operator
- structural genes
36
RNA polymerase
binding site.
Promoter
37
Repressor binding site.
Operator
38
lacZ (β-galactosidase), lacY (permease),
lacA (transacetylase).
Structural genes
39
Operon is __ when tryptophan is
low.
ON
40
________ present → binds
________→ ________ binds
_______ →transcription ___.
Tryptophan present→binds
repressor→repressor binds
operator→transcription OFF.
41
More complex and multi-layered than in proaryotes
Eukaryotic gene operation
42
levels of control in eukaryotic
- chromatin remodeling
- transcriptional regulation
- post-transcriptional control
- translational control
- post-translation modifications
43
condition caused by
abnormalities in the genome.
genetic disease
44
45
genetic diseases can result in:
1.
2.
3.
- single-gene mutations
- chromosomal
abnormalities
- multifactorial interactions
between genes and the environment.
46
how did Mendel study inheritance patterns?
crossed pea plants with green seeds and yellow seeds
47
Types of Genetic Diseases
- single-gene (Mendelian) disorders
- multifactorial disorders
- chromosomal disorders
- mitochondrial disorders
48
Caused by mutations in one
gene; inherited in clear
patterns.
Single-Gene (Mendelian)
Disorders
49
Result from changes in
chromosome number or
structure.
Chromosomal Disorders
50
Involve complex interactions
between multiple genes and
environmental factors.
Multifactorial Disorders
51
Passed from mother to all
offspring due to mutations in
mitochondrial DNA.
Mitochondrial Disorders
52
SINGLE-GENE (MENDELIAN DISORDERS)
- Autosomal Dominant
- Autosomal Recessive
- X-linked Recessive
53
Only one mutated copy
needed.
Autosomal Dominant
54
examples of autosomal dominant
Huntington's disease
Marfan syndrome
55
two copies needed
autosomal recessive
56
examples of autosomal recessive
Cystic fibrosis
Tay-Sachs disease
57
Males more affected (one X
chromosome).
X-linked Recessive
58
examples of X-linked Recessive
Hemophilia A
Duchenne muscular dystrophy
59
CHROMOSOMAL DISORDERS
- Numerical Abnormalities
- Structural Abnormalities
60
Numerical Abnomalities
Trisomy 21
Turner Syndrome (XO)
61
Extra copy of
chromosome 21.
Trisomy 21 (down syndrome)
62
Monosomy of X
chromosome in females.
Turner syndrome (XO)
63
Structural abnormalities
deletions, duplications, translocations
example: Cri-du-chat syndrome (5p deletion)
64
multifactorial disorders
diabetes
hypertension
many cancers
asthma
65
mitochondrial disorders
Leber’s hereditary optic neuropathy.
66
father of Genetics
Gregor Mendel
67
In ____ ,_______ _______, an ______ ____,
began experimenting with pea plants to
study how traits are inherited.
1866
Gregor Mendel
Austrian monk
68
His work with ________________ and _______________ allowed him to discover patterns
in inheritance.
self-fertilization
cross-pollination
69
the study of howgenes
determine traits and howthese
traits are passed down from one
generation to the next.
Genetics
70
explains how offspring inherit
characteristics and helps us
understand the patterns of
inheritance.
Genetics
71
a physical
characteristic thatis
inherited from one
generation to the next.
example: yellow seed color, green seed color
Trait
72
controls a
specific trait, but genes
can have different
versions.
genes
73
different versions of a gene are called
alleles (e.g. yellow seed allele (Y), green seed allele (y))
74
75
The combination of
______ an organism
has will decide what
traitis seen.
alleles
76
what does it mean when alleles are dominant?
they will always show up in an
organism’s appearance if they are present
77
what does it mean when the alleles are recessive?
they are only visible if both alleles are recessive
78
dominant: yellow (Y)
recessive: green (y)
YY
homozygous dominant
79
dominant: yellow (Y)
recessive: green (y)
Yy
heterozygous dominant
80
dominant: yellow (Y)
recessive: green (y)
yy
homozygous recessive
81
- an organism’s genetic makeup, and the
combination of alleles it has for a trait.
- Represents the genes (letters).
Genotype
82
- the physical characteristic thatresults
from the genotype.
- Represents the physical traits.
Phenotype
