Eukaryotic Development and Cancer Genetics

These flashcards are designed to help students review key concepts and details related to eukaryotic development, mutations, cancer genetics, biotechnology, and ethical considerations in genetic research.

Morphogens are __ that diffuse through embryonic tissues to form concentration gradients, directing cell fate.

signaling molecules

An example of a morphogen involved in limb development is __.

Sonic hedgehog (Shh)

Gap genes in segmentation define __ regions in the embryo.

broad

An example of a gap gene is __ in Drosophila.

hunchback

Pair-rule genes refine segmentation, examples being and .

even-skipped and fushi tarazu

Segment polarity genes define __ boundaries in the embryo.

segment

E.g. of segment polarity genes are and .

engrailed and wingless

Hox genes encode transcription factors that regulate __.

body patterning

Hox genes are organized in __, collinear with body segmentation.

clusters

Mutations in Hox genes can lead to __ transformations, such as antenna-to-leg transformation in Drosophila.

homeotic

Hormones regulate gene expression via __ binding.

receptor

An example of a hormone is __ which binds to estrogen receptors to activate transcription.

Estrogen

Growth factors trigger __ signaling cascades.

intracellular

An example of a growth factor is __, which activates cell division.

Epidermal growth factor (EGF)

Promoters control where and when a gene is __.

expressed

Oxytocin and vasopressin receptor genes have -specific enhancers regulating social behavior.

tissue

Repeated DNA sequences, or __, affect vasopressin receptor gene expression.

microsatellites

Variation in microsatellites correlates with vs. behaviors in voles.

monogamous / polygamous

Reporter gene expression is used to study gene __.

regulation

Common examples of reporter genes include and .

GFP (Green Fluorescent Protein) / luciferase assays

MyoD is a master regulator of __ differentiation.

muscle

Myostatin __ muscle growth; mutation leads to increased muscle mass.

inhibits

Loss of __ elements contributed to unique human traits.

regulatory

Acetylation by HATs leads to gene __.

activation

Histone modifications compose the __ that dictate transcriptional outcomes.

histone code

Epigenetics involves heritable changes in gene expression without __ alteration.

DNA sequence

__ suppresses gene expression and is associated with CpG islands.

DNA methylation

HATs activate genes, while __ repress them.

HDACs

Polycomb complexes maintain long-term gene __.

repression

The missing heritability problem suggests genetic variation explains less heritability than expected, possibly due to __, rare variants, or gene-gene interactions.

epigenetics

Intergenerational inheritance refers to direct exposure effects, while __ inheritance persists beyond directly exposed generations.

transgenerational

Nutrigenomics studies the interaction between diet and __.

gene expression

The Dutch Hunger Winter caused epigenetic changes affecting __ generations.

later

The Thrifty Phenotype Hypothesis proposes fetal adaptations to __ increase disease risk when abundance returns.

scarcity

Ecological epigenetics examines epigenetic changes in response to __ factors.

environmental

Glucocorticoid receptor expression is affected by __ care, influencing stress resilience.

maternal

Genomic imprinting means certain genes are expressed from only __ parent(s).

one

The Genetic Conflict Hypothesis states paternal genes favor growth, while maternal genes restrict it, illustrating why both genomes are __.

needed

Imprinting defects can lead to disorders such as and syndromes.

Prader-Willi / Angelman

lncRNA regulates gene expression via __.

chromatin remodeling.

Antisense RNA blocks the __ of complementary mRNA.

translation

piRNA serves to silence __ in germ cells.

transposons

siRNA and miRNA mediate __ interference.

RNA

Dicer cuts double-stranded RNA into or .

siRNA / miRNA

RISC stands for __, which targets complementary mRNA for degradation or repression.

RNA-Induced Silencing Complex

Germ-line mutations occur in __ cells and can be passed to offspring.

reproductive

An example of a germ-line mutation is a mutation in the __ gene that increases hereditary breast cancer risk.

BRCA1

Somatic mutations occur in __ cells and cannot be inherited.

body (somatic)

Somatic mutations can lead to localized effects, such as or .

cancer / mosaicism

Mutation rates are measured as mutations per gene per __ or per generation.

cell division

The average human mutation rate is about __ mutation per 100 million base pairs per generation.

1

Environmental __ are factors that can increase mutation rates.

mutagens

Spontaneous errors in DNA replication can lead to __ rates.

mutation

Xeroderma Pigmentosum is a condition where individuals lack proper __ repair, leading to skin cancer.

UV-induced damage.

Aneuploidy refers to the gain or loss of __ chromosomes.

individual

Trisomy 21 is an example of __, which is a type of chromosomal variation.

aneuploidy

Polyploidy involves having __ sets of chromosomes, common in plants.

extra

Charcot-Marie-Tooth disease results from __ of PMP22 gene as a form of chromosomal rearrangement.

duplication

Hemophilia A is linked to an __ on the X chromosome.

inversion

Chronic Myeloid Leukemia (CML) results from a reciprocal __ between chromosomes 9 and 22.

translocation

Base substitutions are a form of molecular changes leading to __ mutations.

gene

Insertions and deletions can cause __ mutations.

frameshift

Huntington’s disease is associated with __ nucleotide repeats.

expanding

Transition mutations are the exchange of either purine ↔ __ or pyrimidine ↔ pyrimidine.

purine

Transversion mutations are the exchange of purine ↔ __.

pyrimidine

In sickle cell anemia, a transversion mutation changes A to __ in the hemoglobin gene.

T

Frameshift mutations do not occur when insertions/deletions are in __ of three.

multiples

Cystic fibrosis (ΔF508 mutation) is an example of a __ mutation, which preserves the reading frame.

3-base-pair deletion.

A silent mutation results in __ in the amino acid sequence.

no change

An example of a missense mutation is __ (Glu → Val).

Sickle cell anemia

A nonsense mutation creates a premature __ codon.

stop

Tay-Sachs disease has frameshift mutations due to __ or deletions in the HEXA gene.

insertions

Down syndrome results from __, resulting in gene overexpression.

trisomy 21

Fragile X syndrome is associated with __ CGG repeats, leading to chromosomal fragility.

expanded

Pseudodominance refers to the expression of a __ allele when a dominant allele is deleted.

recessive

There are two types of inversions: and .

pericentric / paracentric

Reciprocal translocations involve __ exchange between two chromosomes.

equal

Nonreciprocal translocations involve __ exchange between chromosomes.

unequal

Robertsonian translocations fuse two __ chromosomes.

acrocentric

Turner Syndrome (XO) is an example of __, resulting from aneuploidy.

monosomy

Down Syndrome is an example of __, resulting from aneuploidy.

trisomy

Autopolyploidy involves duplication occurring within __ species.

one

Allopolyploidy results from hybridization between __.

species

Depurination results in the loss of a __, leading to random base incorporation.

purine

Oxidative radicals can cause __ breaks in DNA.

strand

Intercalating agents like __ insert into DNA, causing frameshifts.

Ethidium bromide

X-rays can cause __-strand breaks in DNA.

double

Thymine dimers are created by __ light, blocking DNA replication.

UV

DNA polymerase corrects errors during the __ process.

proofreading

Mismatch repair fixes replication __ through another corrective pathway.

errors

Nucleotide excision repair removes __-induced thymine dimers, preventing mutations.

UV

Forward mutations change wild type to __ state.

mutant

Reverse mutations shift a mutant back to __ type.

wild

Suppressor mutations compensate for the first mutation, restoring __.

function

Cancer is characterized by uncontrolled __ division.

cell

Each cancer type is caused by a unique combination of __.

mutations

A typical lung cancer can have __ mutations and many chromosomal rearrangements.

~22,000

Henrietta Lacks' cervical cancer cells became the first __ human cell line, known as HeLa cells.

immortal

HeLa cells are still extensively used in cancer research, including developing the __ vaccine.

polio

Cancer cells ignore signals to stop __, evade apoptosis, and ignore contact inhibition.

dividing