Genetics Exam 4

cancer

A disease characterized by uncontrolled cell division and the ability to invade other tissues due to accumulated genetic mutations

tumor

A mass of abnormal cells that results from uncontrolled cell division

apoptosis

Programmed cell death that eliminates damaged or unnecessary cells

senescence

A permanent state of cell cycle arrest where cells no longer divide but remain metabolically active

angiogenesis

The formation of new blood vessels, often stimulated by tumors to supply nutrients and oxygen

tumor suppressor genes

Genes that normally prevent uncontrolled cell growth

loss-of-function mutation

A mutation that reduces or eliminates the activity of a gene product, often affecting tumor suppressor genes

proto-oncogenes

Normal genes that promote cell growth and division

oncogenes

Mutated proto-oncogenes that drive uncontrolled cell proliferation

gain-of-function mutation

A mutation that increases or creates new activity of a gene product, often seen in oncogenes

cell cycle checkpoints

Control mechanisms that ensure proper cell division

cyclins

Regulatory proteins whose levels fluctuate to control progression through the cell cycle

CDKs

Cyclin-dependent kinases

p53

A tumor suppressor protein that regulates the cell cycle and triggers apoptosis if DNA damage is detected

Ras

A proto-oncogene that encodes a signaling protein involved in cell growth

benign

A non-cancerous tumor that does not invade nearby tissue or spread

malignant

A cancerous tumor capable of invading nearby tissues and spreading

metastatic

Refers to cancer that has spread from its original site to other parts of the body

lymphatic system

A network of vessels and nodes that can transport cancer cells during metastasis

TNM stages

A cancer staging system based on Tumor size, Node involvement, and Metastasis

radiation therapy

Cancer treatment that uses high-energy radiation to kill or damage cancer cells

chemotherapy

Treatment using drugs that kill rapidly dividing cells

somatic mutation and cancer

Mutations in somatic (body) cells can accumulate and disrupt genes controlling growth, leading to cancer

cancer as a multistep process

Cancer develops through accumulation of multiple mutations affecting cell growth, division, and survival

define cancer

A disease of uncontrolled cell growth with the ability to invade and spread due to genetic mutations

types of cancer genes

Tumor suppressor genes (inhibit growth) and proto-oncogenes (promote growth)

hallmarks of cancer

Characteristics of cancer cells including sustained growth, evasion of apoptosis, angiogenesis, and metastasis

G1 checkpoint

Ensures cell size, nutrients, and DNA integrity are adequate before DNA replication

G2 checkpoint

Ensures DNA replication is complete and undamaged before mitosis

M checkpoint

Ensures chromosomes are properly attached to spindle fibers before cell division

cyclins and CDKs regulation

Cyclins bind CDKs to activate them, allowing progression through different stages of the cell cycle

cancer vs tumor

A tumor is any abnormal mass of cells

TNM staging explanation

T describes tumor size, N describes lymph node involvement, and M describes presence of metastasis

genetic engineering

The direct manipulation of an organism’s DNA to alter its characteristics

CRISPR/Cas9

A gene-editing system that uses a guide RNA to direct the Cas9 enzyme to cut DNA at specific locations

retroviruses

Viruses used as vectors to insert genetic material into host cells

Agrobacterium

A bacterium used to transfer genes into plants

TALENs

Engineered proteins that cut specific DNA sequences for gene editing

artificial breeding vs genetic engineering

Both alter traits, but artificial breeding selects existing traits while genetic engineering directly modifies DNA

types of genetic modifications

Include gene knockout, knockin, knockdown, and targeted mutation

GMOs

Organisms whose DNA has been altered using genetic engineering techniques

GMO controversies

Concerns include safety, environmental impact, corporate control, and labeling

benefits of genetic engineering

Improved crops, disease treatment, increased food production, and medical advances

drawbacks of genetic engineering

Potential health risks, environmental harm, and ethical concerns

ethical concerns GMOs

Issues include biodiversity loss, food safety, and fairness in access

human/environmental consequences

GMOs may affect ecosystems, gene flow, and human health outcomes

knockout

A genetic modification where a gene is completely disabled

knockin

Insertion of a gene or DNA sequence into a specific location

knockdown

Reduction of gene expression, often using RNA interference

target mutation

A deliberate change to a specific DNA sequence

gene modification

Any alteration made to an organism’s DNA

microinjection

Direct injection of DNA into cells using a fine needle

biolistics

A method that uses high-velocity particles to deliver DNA into cells

nanoparticles

Tiny particles used to deliver genetic material into cells

vector

A carrier used to transfer genetic material into a cell

RNAi

A process that silences gene expression by degrading mRNA

endonucleases

Enzymes that cut DNA strands at specific sequences

meganucleases

Highly specific endonucleases used in gene editing

ZFN

Zinc finger nucleases engineered to cut specific DNA sequences

gene therapy

Treatment that involves inserting, altering, or replacing genes to treat disease

germ line

Reproductive cells whose genetic changes can be inherited

somatic cells

Body cells whose genetic changes are not passed to offspring

off-target effects

Unintended genetic changes at sites other than the target

gene editing

The process of making precise changes to DNA

gene selection

Choosing organisms with desirable traits for reproduction

SCID

Severe combined immunodeficiency, a genetic disorder often treated with gene therapy

CAR-T

A therapy where T cells are genetically modified to attack cancer cells

in vivo

Gene therapy performed inside the living organism

ex vivo

Cells are modified outside the body and then reintroduced

in situ

Gene therapy delivered directly to a specific site in the body

CRISPR/Cas9 and gRNA

System where guide RNA directs Cas9 to a specific DNA sequence for editing

mosaic

An organism with cells of different genetic makeup

chimera

An organism composed of cells from different zygotes

Roundup Ready crops

Genetically engineered crops resistant to herbicides

Bt crops

Crops engineered to produce a toxin that kills insect pests

gene drive

A genetic system that increases the likelihood a gene is inherited

biofortification

Enhancing the nutritional value of crops through genetic modification

gene therapy benefits

Can treat or cure genetic diseases by correcting defective genes

CAR-T therapy explanation

Patient T cells are modified to recognize and destroy cancer cells

ethical concerns human modification

Issues include consent, inequality, and unintended consequences