final exam Flashcards
(81 cards)
1
Q
cell cycle phases
A
(G1, S phase, G2) - interphase
& mitotic phase
2
Q
g1
A
(interphase) initial growth phase, cell accumulates materials for DNA replication
3
Q
s phase
A
(interphase) DNA replication occurs
4
Q
g2
A
(interphase) cell continues to grow and prepares for mitosis
5
Q
mitotic phase
A
cell divides, mitosis produces two identical cells
6
Q
interphase
A
G1, s-phase, G2
7
Q
prophase
A
nuclear envelope breaks down to access chromosomes
8
Q
metaphase
A
chromosomes align at the metaphase plate
9
Q
anaphase
A
sister chromatids separate
10
Q
telophase
A
nuclear envelope rebuilds around sister chromatids
11
Q
cytokinesis
A
division of the cytoplasm following mitosis or meiosis
12
Q
prokaryotic genome
A
single, circular DNA molecule
13
Q
genome
A
complete set of DNA within the nucleus (eukaryotes) or single molecule (prokaryotes)
14
Q
centrosome
A
organizes mitotic spindle for cell division
15
Q
meiosis
A
creates genetic variation and reduces chromosome number by half in gametes, preparing for fertilization, meiosis results in four genetically diverse cells
16
Q
gametes
A
reproductive cells, like sperm and egg
17
Q
cytokinesis
A
division of the cytoplasm following mitosis or meiosis
human diploid cells contain 46 chromosomes: haploid gametes contain 23
18
Q
crossing over
A
exchange of genetic material in prophase 1. Genetic material exchange, creating recombinants
19
Q
homologous chromosomes
A
chromosomes with the same length and gene types
20
Q
fertilization
A
fusion of haploid gametes to form a diploid zygote
21
Q
genetic variation
A
due to meiosis and fertilization
22
Q
G2 checkpoint
A
checks for complete, undamaged DNA before mitosis
23
Q
proto-oncogenes
A
regulate cell growth, mutations can lead to uncontrolled cell division (cancer)
24
Q
p53
A
tumor suppressor that halts the cell cycle for DNA repair or induces apoptosis in damaged cells, helping prevent cancer
25
mutations in p53 and RB1
prevent the cell from stopping division despite damage, often seen in cancer cells
26
genetics
the study of heredity and variation in living organisms
27
gregor mendel
known as the father of genetics, mendel's experiments with pea plants established foundational principles in genetics. His works form the basis of mendelian genetics, a framework for understanding inheritance patterns
28
p (parental generation)
true-breeding plants with distinct traits (e.g, purple flowers vs white flowers)
29
F1 generation
offspring of the P generation, all expressing the dominant trait (purple flowers)
30
F2 generation
offspring of the F1 generation, showing a 3:1 ration of dominant to recessive traits
31
mendel's observations
traits are inherited as discrete units (genes), not blended
dominant traits mask recessive traits in heterozygous individuals
32
phenotype
observable traits of an organism
33
genotype
the genetic makeup that determines the phenotype
34
homozygous
two identical alleles (PP or pp)
35
heterozygous
two different alleles (Pp)
36
Law of dominance
in heterozygous organisms, one allele (dominant) can mask the expression of another (recessive)
37
law of segregation
during gamete formation, alleles for each gene segregate, ensuring offspring inherit one allele from each parent
can be visualized using punnett squares to predict genotype and phenotype ratios
38
law of independent assortment
genes for different traits are inherited independently if they are located on different chromosomes
seed color (yellow/green) and seed shape (round/wrinkled) are inherited independently, resulting in a 9:3:3:1 phenotypic ratio in a dihybrid cross
39
incomplete dominance
heterozygous phenotype is an intermediate between the two homozygous phenotypes
snapdragon flowers where red (RR) x white (WW) = pink (RW)
40
codominance
both alleles are fully expressed in the heterozygote
Human ABO blood group system, individuals with IAIB genotype have type AB blood
41
multiple alleles
a gene with more than two alleles within a population
ABO blood types involve three alleles (IA, IB and i)
42
epistasis
interaction between genes where one gene masks or modifies the effect of another
coat color in labrador retrievers, where a gene for pigment deposition (E/e) determines wheter the color genes (B/b) are expressed
43
polygenic inheritance
traits influenced by multiple genes, resulting in a wide range of phenotypes
human skin color with more dominant alleles = darker skin and more recessive alleles = lighter skin
44
DNA
carriers genetic information
45
DNA structure
double helix made of nucleotides (sugar, phosphate, nitrogen base)
Base pairs: A-T and G-C
46
Eukaryotes
DNA wrapped around histones in chromosomes
47
prokaryotes
circular DNA supercoiled in the nucleoid
48
Basics of DNA replication
DNA replication is the process by which a cell copies its DNA before cell division
purpose: ensures that each daughter cell receives an identical copy of the genetic material
49
semiconservative replication
each new DNA molecule consists of one original strand (template stand) and one newly synthesized strand
50
replication origin
the process begins at specific DNA sequences called origins of replication
prokaryotes: single origin (circular DNA)
eukaryotes: multiple origins (linear DNA)
51
Steps of DNA replication
1) Initiation: unwinding the DNA
2) elongation
3) Termination
52
helicase
enzyme that unwinds double helix, creating two single strands
53
single-strand binding proteins (SSBs)
stabilize the unwound DNA, preventing it from re-annealing
54
topoisomerase
relieves tension in the DNA helix ahead of the replication fork
55
replication fork
y-shaped structure where DNA is unwound and replication occurs
56
primase
adds RNA primers to provide a starting point for DNA synthesis
57
DNA polymerase
adds nucleotides to the 3' end of the primer, synthesizing new DNA
57
leading strand
synthesized continuously in the 5' to 3' direction toward the replication fork
57
lagging strand
synthesized discontinuously as short fragments (okazaki fragments) in the 5' to 3' direction away from the fork
58
sliding clamp
holds DNA polymerase in place to increase efficiency
59
primer removal
RNA primers are replaced with DNA by a different DNA polymerase
60
ligation
DNA ligase seals gaps between okazaki fragments on the lagging strand to form a continuous strand
61
telomeres
(special DNA feature in eukaryotes)
repeated sequences at chromosome ends that protect against loss of genetic information during replication
62
telomerase
(special DNA feature in eukaryotes)
enzyme that extends telomeres in germ cells, stem cells and some cancer cells, preventing chromosome shortening
63
significance of DNA replication
accuracy: DNA replication is highly accurate due to proofreading by DNA polymerase
mutations: errors that escape proofreading can lead to genetic mutations, affecting cell function
64
biotechnology
involves using living organisms or biological systems to develop products and technologies for various fields, including medicine, agriculture and industry
65
vaccines
genetically engineered vaccines like the HPV vaccine (protects against cervical cancer)
mRNA vaccines (eg, COVID-19 vaccines) use synthetic genetic material to trigger immunity
66
antibiotics
naturally produced by microorganisms (penicillin by fungi)
genetic engineering has increased yield and efficiency
67
Hormones and therapeutics
insulin - recombinant DNA technology produces human insulin in bacteria for diabetes treatment
human growth hormone (HGH) - used for growth disorders, produced using genetically modified bacteria
68
genetically modified organisms (GMOs)
crops engineered for pest resistance (Bt corn), herbicide tolerance (soybeans) and increased nutritional value (golden rice)
reduced reliance on chemical pesticides and fertilizers
69
transgenic animals
animals modified to express human proteins (anticoagulants in goat milk)
used for research and pharmaceutical production
70
biofuels
genetically engineered microbes produce ethanol or biodiesel
71
bioremediation
microbes designed to clean up oil spills or detoxify pollutants
72
DNA and RNA isolation
key technique in biotechnology
involves breaking cell membranes, removing proteins, and isolating nucleic acids for analysis or modification
73
gel electrophoresis
purpose - separates DNA fragments by size
process - DNA is loaded into a gel, and an electric current pulls smaller fragments faster through the gel matrix
74
Polymerase chain reaction (PCR)
purpose - very quickly amplifies small DNA segments to detectable levels
applications:
forensics - DNA profiling from crime scenes
medical diagnostics - detecting pathogens or genetic mutations
research - need a lot of specific DNA sequence for experiments
75
molecular cloning
copies specific DNA segments
76
genetic engineering & recombinant DNA technology
combines DNA from different sources to create new functions
77
plasmid vectors
small circular DNA used to introduce foreign genes into host cells
78
restriction enzymes
molecular scissors that cut DNA at specific sequences, enabling gene insertion
79
gene editing (CRISPR-Cas9)
revolutionary technology allows precise cutting and modification of DNA
- treating genetic disorder (sickle cell anemia)
- developing disease-resistant crops
