Biology Exam 2 - Cancer, Disease, and Mitosis (I)

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Cancer

disease that is caused by the inability of the body to control the division of cells

Melanoma

a type of skin cancer that develops from melanocytes, the cells that produce pigment in the skin.

Leukemia

a type of cancer that affects the blood and bone marrow, characterized by the overproduction of abnormal white blood cells.

Carcinoma

a type of cancer that originates in the epithelial cells, which line the surfaces and cavities of organs.

Sarcoma

a type of cancer that arises from connective tissues, such as bone, cartilage, fat, or muscle.

Lymphoma

a type of cancer that originates in the lymphatic system, often affecting lymph nodes and immune cells.

Characteristics

Not specialized, irregularly shaped, immortal (over-repair telomeres)

Angiogenesis

new blood vessels growing from already-existing blood vessels

Telomeres

Repetitive sequences of DNA at the end of chromosomes that act as a buffer when replicating DNA; when too short, cells are not allowed to replicate

Telomerase Enzyme

Associated with cancer; repairs telomeres

Endocrine System

Secretes hormones to coordinate / regulate other systems (slow)

Nervous System

Coordinates / regulates other systems, reacts to stimuli (fast)

Respiratory System

Supplies blood with oxygen for tissues; gets rid of carbon dioxide, regulates blood pH

Cardiovascular System

Transports oxygen and nutrients to tissue cells, transports waste away from cells, transports endocrine hormones

Digestive System

Supplies blood with water, nutrients for tissue cells

Muscular System

Produces heat to maintain body temperature, protects and supports internal organs, allows for movement

Integumentary System

Helps protect inner organs and maintains body temperature

Lymphatic System

Helps maintain blood volume by collecting excess intestinal fluids and then returning it to the cardiovascular veins; defends against disease

Urinary System

Excretes nitrogenous and other wastes, regulates water-salt balance of blood, helps regulate blood pH

Tumor

A mass of unspecialized cells that continues to accumulate, can be benign or malignant

Metastasis

When cancer cells spread from their original location to other parts of the body, often through the blood or lymphatic system

Benign tumor

Noncancerous tumor; usually remains in one location, does not spread to nearby tissues or other parts of body

Malignant tumor

Cancerous tumor; cells invade surrounding tissues and may spread to other parts of the body

Stage 0

Abnormal cells are present but have not invaded nearby tissue. Often called carcinoma in situ.

Stage 1 [Cancer]

Cancer is relatively small and localized to its original location

Stage 2 [Cancer]

Cancer may be larger or have grown further into nearby tissue.

Stage 3 [Cancer]

Cancer has spread more extensively into nearby tissues and/or regional lymph nodes.

Stage 4 [Cancer]

Cancer has spread to distant parts of the body. This is called metastatic cancer.

Homeostasis

Process by which an organism maintains a relatively stable internal environment despite changes inside or outside the body

Polymerase Chain Reaction (PCR)

Blood is drawn, DNA is then isolated from white blood cells and subjected to this process to make copies of gene of interest.

DNA Sequencing

Fluorescent tags are added to nucleotides in a DNA molecule and chemical reactions remove one nucleotide at a time. A laser identifies the nucleotide based on its fluorescent tag and a computerized output is created.

Microarrays

Screens genetic information, allows doctor to search for specific mutations or differences in gene expression between normal cells and cancer cells

Personalized Genetic Testing

Looks for specific alleles associated with cancer in an individual

Complete Blood Counts (CBCs)

Examine presence of normal blood cells, basic blood chemistry, and changes in blood calcium, enzymes, or ion concentrations may also indicate that cancer is interrupting the function of an organ.

Screening mammogram

X-ray of breast and surrounding tissues that looks for abnormalities associated with cancer

Diagnostic mammogram

X-ray of breast and surrounding tissues, used after finding a lump or suspicious blood work

Computerized tomography (CT) scans

X-ray of organs with pictures from multiple angles that are used to generate a 3D image, can involve dye for contrast

Positron Emission Tomography (PET) scan

Uses radioactive tracers to measure the metabolism of cells, cancer cells are more active and stand out.

Magnetic Resonance Imaging (MRI)

Uses radio waves and magnets to generate detailed images of the body

Chemotherapy

The use of drugs to treat disease. In the case of cancer, this works by targeting the cell cycle to prevent cell division in rapidly dividing cells.

Alkylating agents

chemicals that integrate into the DNA, causing it to break at specific points; general and so can cause long-term side effects including other cancers

Alkaloids

chemicals naturally produced by some plants; prevent cells from forming spindle fibers, thus preventing cell division

Taxanes

naturally produced by yew trees; prevent microtubule breakdown during cell division so cell division doesn’t continue

Antimetabolites

chemicals that mimic nucleotides and are integrated into DNA, but interfere with DNA replication, preventing cell division

Antitumor antibiotics

prevent the enzymes involved in DNA replication from functioning, or interfere with the ability of the DNA to form RNA during gene expression.

Topoisomerase inhibitors

chemicals that disable topoisomerase enzyme, preventing DNA replication

Radiation

The movement of energy in waves or particles. The shorter the wavelength, the more energy present.

Immunotherapy

involves convincing the body’s immune system to identify and eliminate cancer cells as “nonself” instead of “self.” Can also include vaccines and introduced antibodies, such as “monoclonal antibodies”

Gene therapy

involves the insertion of genetic material (DNA or RNA) into human cells for the purpose of treating a genetic disorder; aims to provide cells with a correct copy of a gene

Genome Editing

a group of technologies that gives scientists the ability to change an organism's DNA by adding, removing, or altering genetic material at specific locations in the genome

CRISPR

A form of genomic editing, uses the enzyme Cas9 to identify specific sequences of nucleotides using guide RNA molecules to inactivate genes, remove sections of nucleotides, or insert new sets of nucleotides.

Sickled Cells

Incorrectly formed hemoglobin proteins within red blood cells, which become unable to transport oxygen to tissues of the body

Enzyme

protein catalyst that helps a chemical reaction occur

Active site

specific region of an enzyme where a molecule interacts with the enzyme

Substrate

molecule that binds to the enzyme active site

Product

molecule(s) produced by the enzyme reaction

Cancer Drug’s Role in Enzymes

Binds to enzyme’s active site, disallowing the substrates from properly interacting with the enzyme to prevent a reaction.

Tumor-Suppressor Genes

Prevents unregulated cell growth by slowing down the cell cycle. One way of doing so is by producing proteins to survey DNA for damage; some genes include p53 and BRCA1 for breast cancer.

p53, BRCA-1 and ERBB2 are all associated with…

Breast cancer

Proto-Oncogenes

Speed up / promote the cell cycle, which includes cell division.

Mutations

Changes to the nucleotide sequence of DNA; can be caused by chemicals (carcinogens), radiation exposure, or viruses; may or may not affect protein structure

Chromatin

The material that makes up chromosomes, consisting of DNA wrapped around proteins.

Nucleosome

The basic unit of chromatin. It consists of a segment of DNA wrapped around proteins called histones.

Somatic cell

Any ordinary body cell that is not a reproductive cell. Examples include skin, muscle, and nerve cells.

Gamete

A reproductive sex cell. In humans, these are sperm and egg cells

Karyotype

An organized display of an individual's chromosomes, arranged into matching pairs according to size, shape, and other characteristics.

Autosomes

All chromosomes that are not sex chromosomes

Diploid

A cell containing two complete sets of chromosomes, one set inherited from each parent.

Haploid

A cell containing only one complete set of chromosomes.

Homologous chromosomes

A pair of chromosomes, one inherited from each parent, that contain the same genes in corresponding locations.

Nondisjunction

The failure of chromosomes or sister chromatids to separate properly during cell division. This can result in cells or gametes having an abnormal number of chromosomes.

Structure of a Replicated / Duplicated Chromosome

Consists of two identical sister chromatids joined together at a centromere.

Sister Chromatids

Two identical copies of a replicated chromosome.

Centromere

The region where the two sister chromatids are attached.

Mitosis

the process in which a cell divides its nucleus, distributing duplicated chromosomes into two new nuclei. Produces two identical, diploid daughter cells

Prophase

The first stage of mitosis. Chromatin condenses into visible chromosomes; nuclear envelope breaks down; spindle fibers begin to form; centrosomes move towards opposite ends of the cell.

Metaphase

The second stage of mitosis. Chromosomes line up along the middle of the cell; spindle fibers attach to the chromosomes at their kinetochores; sister chromatids are positioned to be separated.

Anaphase

The third stage of mitosis. Sister chromatids separate from one another; spindle fibers pull them toward opposite ends of the cell; each separated chromatid is now considered an individual chromosome.

Telophase

The fourth stage of mitosis. Chromosomes reach opposite ends of the cell; new nuclear envelopes form around each group of chromosomes; chromosomes begin to uncoil back into chromatin; spindle fibers break down.

Animal Cell Cytokinesis

Forms a cleavage furrow; cell membrane pinches inward; splits the cell from the outside toward the center.

Plant Cell Cytokinesis

Form a cell plate; vesicles collect in the middle; cell plate grows outward, forms a new cell wall.

Interphase

Period of the cell cycle during which a cell grows, performs its normal functions, replicates its DNA, and prepares for cell division. Not part of mitosis. Consists of 3 stages.

G1 Phase

Cell Growth checkpoint of Interphase; cell grows in size, cell performs its normal functions, cell produces proteins and organelles, and prepares for DNA replication.

S / ‘Synthesis’ Phase

Where DNA Replication occurs. The cell makes an identical copy of its DNA, each chromosome is duplicated and each of those chromosomes consist of two identical sister chromatids. The sister chromatids remain attached at the centromere.

G2 Phase

Cell continues to grow, produces additional proteins and organelles, checks the replicated DNA for errors, makes final preparations for mitosis.

‘M’ Phase

Mitosis, and generally contains cytokinesis.

Meiosis

A type of cell division that produces haploid reproductive cells (gametes) from a diploid parent cell.

Meiosis I

Separation of homologous chromosomes. Called the ‘reductional division’ as it reduces the chromosome number from diploid to haploid.

Prophase I

The first stage of Meiosis I; chromosomes condense and become visible, homologous chromosomes pair together, each pair forms a structure called a tetrad, crossing over occurs between non-sister chromatids of homologous chromosomes, nuclear envelope breaks down and spindle fibers form.

Metaphase I

The second stage of Meiosis I; homologous chromosome pairs called tetrads line up along the middle of the cell, the orientation of each pair is random, spindle fibers attach to the homologous chromosomes.

Anaphase I

The third stage of Meiosis I; homologous chromosomes separate, one chromosome from each homologous pair moves toward each opposite pole, sister chromatids remain attached at their centromeres.

Telophase I and Cytokinesis

The fourth stage of Meiosis I; the chromosomes reach opposite poles, nuclear envelopes may reform, cytokinesis divides the original cells into two cells. Two haploid cells are produced.

Meiosis II

Separation of sister chromatids. The “equational division” because sister chromatids separate without further reducing the chromosome set number. It resembles mitosis in terms of chromosome separation.

Prophase II

The first stage of Meiosis II; Chromosomes condense if they had uncoiled; then nuclear envelopes break down if present, and new spindle fibers form in each cell. Two cells begin preparing for another division

Metaphase II

The second stage of Meiosis II; chromosomes line up individually along the middle of each cell, spindle fibers attach to the sister chromatids.

Anaphase II

The third stage of Meiosis II; centromeres divide, sister chromatids separate from one another, the separated chromatids move toward opposite poles, each separated chromatid is now considered an individual chromosome

Telophase II and Cytokinesis

The fourth stage of Meiosis II; chromosomes reach opposite poles, nuclear envelopes reform, chromosomes begin to uncoil, cytokinesis divides both cells. Four haploid daughter cells are produced.

Crossing over

The exchange of corresponding segments of DNA between non-sister chromatids of homologous chromosomes during Prophase I of meiosis. Important for increasing genetic variation, and it produced new combinations of alleles.

Final Results of Meiosis - Are the four daughter cells identical?

No

Final Results of Meiosis - Are the resulting cells diploid or haploid?

Haploid