FULL BIO FINAL

Cancer

disease that occurs when a cell makes copies of itself, or replicates, when it should not

Mitosis

the type of cell division that occurs when one parent cell divides to form two daughter cells

Tumor

a solid mass of cells that has no apparent function in the body

benign

tumors that stay in one place and do not affect surrounding structures; some remain harmless, some become cancerous

malignant

invasive tumors that infiltrate surrounding tissues

metastasis

occurs when the cells of a malignant tumor break away and start new cancers at distant locations, happens through the circulatory system or lymphatic system

risk factor

condition or behavior that increases the likelihood of developing a disease

types of risk factor

inherited, environmental

carcinogens

particular substances that, when exposed to, correlate with development of particular cancers

synergistic

one carcinogen enhances the activity of another carcinogen

asexual reproduction

reproduction via making exact copies

sexual reproduction

reproduction that requires genetic information from two parents

DNA (deoxyribonucleic acid)

a cell's genetic material

genes

instructions for the construction of proteins that a cell requires

chromosomes

structures that are made by DNA wrapping around proteins, reside in the nucleus

sister chromatids

duplicated chromosomes attached to each other, exact copies

centromere

where sister chromatids are attached

DNA replication

when the double-stranded DNA molecule is copied

steps of DNA replication

division of the helix via helicase addition of new nucleotides via DNA polymerase

semiconservative replication

when a new strand of DNA has one-half conserved parent strand and one new synthesized strand

DNA polymerase

the enzyme responsible for DNA replication

mutations

changes in the DNA of a gene

somatic cells

cells that do not produce sex cells

stages of cell cycle

interphase prophase metaphase anaphase telophase cytokinesis

interphase

when the DNA in the cell replicates, cell spends most of its time in this state

G1 stage

stage of interphase when cell grows and organelles duplicate

S stage

stage of interphase when the DNA replicates

G2 phase

stage of interphase where cell continues growth and prepares for mitosis

prophase

first stage of mitosis and meiosis, replicated chromosomes condense, microtubules form and grow, nuclear envelope begins to break down meiosis: in prophase I, crossing over may occur

centrioles

structures that anchor the microtubules

metaphase

second stage of mitosis and meiosis, when the chromosomes line up in the center of the cell and microtubules attach to the centromeres meiosis: in metaphase I, random alignment occurs

anaphase

third stage of mitosis and meiosis, when the microtubules pull the sister chromatids apart from each other

telophase

fourth stage of mitosis and meiosis, when the nuclear envelope reforms around the new daughter nuclei

cytokinesis

phase during and after telophase when the daughter cells separate themselves

cancer checkpoints in a cell cycle

G1 (Is cell division necessary, is the cell large enough for G2)

G2 (Was DNA replicated correctly)

M (Are all of the chromosomes attached to the microtubules)

gametes

sperm and egg cells, only have 23 chromosomes each, has no chromosome pairs

karyotype

someone's full set of 23 pairs, 46 chromosomes

homologous chromosomes

chromosomes that pair up during meiosis (one from each parent, same genes different expression)

proto-oncogene

gene that produce proteins to control the cell cycle, has the potential to become an oncogene

oncogene

mutated proto-oncogene, may overstimulate cell division or not properly regulate it

tumor suppressor gene

genes that prevent cell division if conditions are unfavorable, when mutated can allow cells to override checkpoints

angiogenesis

tumor gets its own blood supply

loss of contact inhibition

cells now pile up on each other

loss of anchorage dependence

enables a cancer cell to move to another location

immortalized

cells have no fixed number of cell divisions

mutations required for cancer growth

angiogenesis loss of contact inhibition loss of anchorage dependence immortalized

multiple hit model

method of tracking gene mutations that may cause cancer

meiosis

cell division that produces reproductive cells

gonads

sex organs

homologous pairs

chromosomes that carry the same genes, but not necessarily the same alleles

alleles

different expressions of a single gene

haploid vs. diploid

haploids(n) have half as many chromosomes as diploids(2n)

autosomes

non-sex chromosomes

sex chromosomes

X and Y, XX for female XY for male, responsible for sex-linked traits

zygote

fertilized cell

crossing over

happens in prophase I of meiosis, when homologous pairs of chromosomes exchange small portions of genetic information on a gene-for-gene basis if it occurs, there will be 4 types of gametes present after meiosis, if it does not, there will be 2 types of gametes

phases of meiosis

interphase prophase I metaphase I anaphase I telophase I cytokinesis prophase II metaphase II anaphase II telophase II cytokinesis

nondisjunction

when homologous pairs fail to separate during meiosis and gametes have uneven numbers of chromosomes

random alignment

occurs during metaphase I in meiosis, pairs of chromosomes are aligned at random, resulting in different types of gametes being formed

phenotype

manifestation and expression of a genetic trait

genotype

the actual genetic makeup/code of a gene

homozygous

having identical alleles in a gene

heterozygous

having two different alleles in a gene

homozygote

an individual with two identical alleles

heterozygote

an individual with two different alleles

generations

P = parent generation, F1 = first generation, F2 = second generation

blood types

A and B are codominant over O

offspring variation causes

mutation random alignment crossing over fertilization

mendels laws

law of segregation law of independent assortment

law of segregation

members of a pair of homologous chromosomes separate during the formation of gametes and are distributed to different gametes so that every gamete receives only one member of the pair

law of independent assortment

each member of a pair of homologous chromosomes separates independently of the members of other pairs so the results are random

linked genes

2 genes on the same chromosome, segregate together

polygenic trait

trait that is controlled by several genes at once

qualitative

relating to or involving comparisons based on qualities (hair color)

quantitative

relating to the measurement of quantity (weight height)

epigenetics

the study of how your behaviors and environment can cause changes that affect the way your genes work

dihybrid cross

hybridization using two traits with two alleles each

incomplete dominance

two dominant allele copies required for the full phenotype (red RR pink Rr white rr)

codominance

neither allele is dominant to the other, both traits express at once with no blending (AB blood type)

pedigree

family tree that shows the inheritance of traits (circle female, square male)

DNA fingerprinting

forensic science method to identify individuals

DNA fingerprinting steps

DNA isolated DNA cut into fragments via enzymes Unique fragmenting is tracked and visualized

pleiotropy

ability of a single gene to cause multiple effects on an individual's phenotype

carrier

does not express a trait but carries it as an allele

phenotypic ratio

ratio of specific phenotype possibilities in a Punnett square (W:X:Y:Z)

multiple allelism

when there are more than two alleles of a gene in the population (A, B, O)

variance

average distance any one individual in the population is from the mean

monozygotic twins (MZ)

twins that develop from one zygote, identical

dizygotic twins (DZ)

twins from two separate eggs and sperm, non-identical

DNA profiling

uses differences in DNA to identify an individual

Short Tandem Repeats (STR)

short repeated DNA sequences commonly used for DNA profiling

Polymerase chain reaction (PCR)

process to duplicate DNA through denaturing and artificial DNA replication

denature

breaking the hydrogen bonds in DNA via heat

gel electrophoresis

method to separate DNA by size, uses agarose gel

ingredients for PCR

DNA, nucleotides, specific primers, Taq polymerase, heat

restriction enzymes

"cuts" the DNA into fragments in DNA profiling

protein synthesis

process of using instructions carried on a gene to create proteins

protein

large molecule composed of amino acids