Biology Module 6

Tumor

• A single cell that divides without restraint can lead to a cell mass called a _____.

Benign Tumor

• a mass of cells confined to its tissue type

  • cells in it are not invasive

Malignant Tumor

• Cancer forms when the tumor becomes ______.

• When tumor cells start invading neighboring tissue

Angiogenesis 

• increases the delivery of oxygen and nutrients to a tumor

  • enabling it to increase in size

Metastasis

• spread of caner cells to other parts of the body through the blood supply

Tumor suppressor/Negative growth repair

• controls cell division

• code for ____ _____ regulators that normally restrain cell division and migration by:

  • Inhibiting the cell cycle

  • Stimulating repair of damaged DNA

  • Promoting cell adhesion

  • Enforce anchorage dependence

  • Preventing angiogenesis

  • Trigger cell suicide (programmed cell death)

• Loss of function in these genes increases a risk of cancer

Oncogene/Positive growth regulator

• controls cell cycle

• includes Proto-oncogenes that function as ___ ____ regulators of stem cells.

• over expression of these genes increases likelihood of cancer development

• _____ aka cancer-causing gene

Proto-oncogene

• function as positive growth regulators of stem cells

• mutations cause these genes to become hyperactive, and trigger excessive cell proliferation and the mutated gene is now known as an oncogene (cancer-causing gene)

Induced pluripotent stem cells

• are derived from differentiated adult cells.

• are genetically reprogrammed to mimic the pluripotent behavior of embryonic stem cells.

• derived from skin or blood cells that have been reprogrammed back into an embryonic-like pluripotent state that enables the development of an unlimited source of any type of human cell needed for therapeutic purposes.

CRISPR

• current most popular technique for genetic engineering.

• Capable of changing nearly any aspect of genetic material

• Clustered regularly interspaced short palindromic repeats

Gene therapy

• a technique to treat specific genetic conditions, like hemophilia.

• DOES NOT alter genetic material

• often involves either proteins created via DNA cloning or mRNA incased in phospholipids

Genetic engineering

• altering the genetic material of one or many organisms

• CRISPR is the current most popular technique of ____ ____.

genetic manipulation

• is when humans discover useful mutations

  • often from selective breeding, then propagate the mutation with more selective breeding

• ex.) GMOs in food to enrich with nutrients

Gene gun

• shoots DNA into organisms seeds to propagate 

• old technique that is mostly used with plants

  • animal cells would break-down

DNA Cloning

• takes artificially made DNA (recombinant DNA) and inserts it into a single celled organism to replicate and translate the gene.

• old technique

  • main engineering technique used to produce medicines and medical tests

Henrietta Lacks

• Cervical cancer cells from ____ ____ were the first human cells to be grown successfully in a lab dish and are still being used today.

• (HeLa) cells are immortal and have the ability to divide indefinitely

Telomeres

• The ends of your chromosomes are very long segments of non-coding DNA called ______. 

• protect genes from being removed because every time a chromosome is replicated the very end of a chromosome gets cut off

• shorten with age

Telomerase

• adds base pairs to the ends of telomeres, increasing their length

• This process causes cancer cells, like HeLa cells, to be immortal

• regulated in some organisms to protect from telomere shortening

• Gamete fusion uses ______ to insure offspring have adequate telomeres

Methylation

• a permanent off switch for genes

  • Plays a role in

    • aging

    • cell differentiation

    • cancer

• blocks access to specific genes

• natural process for turning off genes during cell differentiation.

Cell differentiation 

• a biological process where an unspecialized cell becomes a specialized cell type

  • such as a muscle cell or nerve cell

• through the activation or inactivation of specific genes

Carcinogens/Mutagens

• are physical, chemical, or biological agents that increase the risk of cancer:

  • UV Radiation

  • Bacteria or viruses(retroviruses, T-Cell Lukemia)

  • Increased exposure to hormones(high-levels of growth hormone→ testosterone)

  • Toxic chemicals

Stem Cells

• incompletely differentiated cells that produce one or more differentiated cells, while maintaining itself to divide again

  • purpose is to make more cells

  • embryonic or adult

  • capable of self-renewal

Embryonic stem cells

• type of stem-cell

• only in embryos

• can give rise to essentially any type of specialized cell in the body.

• build organisms + change gene expression

• totipotent + pluripotent

Adult stem cells

• repair, grow, develop

• can give rise to only a few specialized cell types.

• Much More Limited in Their Developmental Potential

• multipotent + unipotent

Totipotent stem cells

• Embryonic stem-cell

• cells which can give rise to all human cell types

• total potential

Pluripotent stem cells

• Embryonic stem-cell

• any cell but cells that make-up birth sac or embryo

• makes up the inner mass of the blastocyst

Multipotent stem cells

• adult stem-cell

• differentiate into a limited number of specialized tissues

  • blood stem cells

Unipotent stem cells

• adult stem-cells

• give rise to only one specialized cell type.

• Imbedded throughout the body, having only a single function, make more cells

• skin cells

Asymmetrical Cell Division

• a process whereby the asymmetric inheritance of cellular components (e.g. proteins, RNAs) during mitosis defines distinct fates for each daughter cell.

• when a parent cell divides into two daughter cells that are different from each other, often in terms of size, fate, or both

• during mitosis + meiosis

Gene drives

• a genetic element that propagates a particular suite of genes throughout a population by altering the probability, relative to standard Mendelian inheritance, that a specific allele will be transmitted to offspring

• altered gene is inherited

RNAi crops

• produce molecules used to stop gene expression.

• cells often produce molecules that destroy specific transcripts of mRNA

• attack genes crucial for the survival of specific groups of insects

BT crops

• Bacillus thuringiensis

• type of bacteria that produces a protein that kills mosquitoes

• The gene for the protein has been extracted, altered to attack other insects and put into the genetics of specific crops.