Genetics Test 1

artificial selection

choosing specific individuals with preferred phenotypes from an initially heterogeneous population for future breeding purposes

8000-5000 BC

domestication of animals followed by artificial selection

5000 BC

Plants were cultivated and domesticated

500-400 BC

school of medicine (hippocrates)

384-322 BC

Aristotle discussed heredity in humans

Theory of Epigenesis

An organism develops from a fertilized egg by a succession of events that transform an egg into an adult

Theory of Preformation

the fertilized egg contains a complete miniature adult called a homunculus

homoculus

microscopic fully developed human contained in the sperm from which a fetus was believed to develop

cell theory

all organisms are composed of basic structural units called cells that come from pre existing cells

Schwann and Schleiden

Cell theory

Theory of Evolution

descent with the modification existing species arose from ancestoral species

Natural Selection

an explanation of the mechanism of evolutionary change for species that evolve over time, and those with the superior traits outcompete those with inferior traits and pass them to their offspring

origin of species

over time better adapted traits accumulate and if isolated result in a new species

Chromosomal Theory of Inheritance

Heredity and development were dependent on genetic information in genes contained in chromosomes, passed down through gametes

innate regulator

organisms are built with an innate regulator

ex: plant stress signal can induce a rapid expression shift

genes

factors that control traits

Diploid State

2n, when chromosomes exist in pairs (46=humans)

Haploid State

n, when chromosomes exist alone (23=humans)

Mitosis

make diploid cells by copying chromosomes and segregating to opposite sides of the cell and then dividing into two new identical cells

Meiosis

create four unique haploid cells from one diploid cell, cuts the chromosomes in half; induces genetic variation

pairs of genes separate like chromosomes (genes are carried on different chromosomes)

Sutton and Boveri discovery

genetics

the branch of biology that studies heredity and variation in organisms

Alleles

different versions of a gene

Wild type allele

the non-mutant form of a gene, encoding the normal genetic function (dominant allele)

mutant allele

is a variant that arises when a gene undergoes a mutation, or change (recessive allele)

genotype

the set of alleles for a given trait

phenotype

the expression of a genotype that produces an observable trait

displayed that dna was a genetic carrier in bacteria (1944)

Avery, MacLeod, McCarty discovery

the genetic material in a virus-killing-bacteria is DNA

Hershey and Chase discovery

double helix structure of DNA

Watson and Crick discovery

nucleotide

the monomer of DNA that consists on a sugar, phosphate, and organic base

codons

triplet nucleotides that encode for insertion of specific amino acids

Sickle cell mutation

missense mutation, CTC -> CAC, glutamine into valine

Biotechnology

the application of biological systems/ living organisms and their derivatives to develop products that benefit humanity and the environment

restriction enzymes

enzymes that can be used to cut DNA molecules into reproducible fragments

restriction site

the place on the DNA molecule where the enzyme cuts, specific, short (6-8), and often palindromic sequences

plasmid

small, circular piece of DNA found in bacteria, seperate from the main chromosome "extra genes"

vector

a plasmid that has been engineered in the lab to carry foreign dna into a host cell

origin of replication

Site where the replication of a DNA molecule begins, allows the plasmid to copy itself

selectable marker

allows scientists to identify bacteria that successfully took up plasmid

multiple cloning site

region with many restriction enzyme sites where foreign dna can be inserted

transformation

the process where bacteria take up external DNA from their environment

bacteria ligation

the process of joining DNA fragments, typically during cloning using an enzyme called DNA ligase

mean more gene dosage and protein expression

high copies of plasmid...

Cisgenic

transfer of heritable traits from the same species

Transgenic

transfer of heritable traits from different species

Isogenic

transfer of heritable traits from identical genetic make up individuals

genomics

the study of the structure, function, and evolution of genes and genomes

Proteomics

study of proteins present in cells that include structure, function, and interactions in biological systems

Bioinformatics

interdisciplinary field that covers biology computer science and information technology to analyze biological data

"common origin"

all cells have dna, cell membrane, and ribosomes

homologs

gene from the same common ancestor, contain the same structure, shape, size and carry different alleles of the same gene

orthologs

similar genes in differing species with the same function

paralogs

a duplicated gene on a chromosome

forward genetics

induce a mutation that causes an altered phenotype, then identify the gene that caused the mutant phenotype

reverse genetics

dna sequence of a particular gene is known, the function is not, mutate gene

gene knockout

rendering genes non functional to investigate the possible role

Model organism

an organism that is studied extensively to understand biological processes

-easy to grow

-short life cycles

-produce many offspring

nucleus

double membraned organelle that houses genetic material

nucleolus

rRNA synthesis site

Nuclear organizer region

chromosomal regions where dna encodes rRNA

nucleoid

prokaryotic region where dna is located in bacteria

microtubules

hollow tubes made up of tubulin to provide support and serve as tracks for motor proteins

microfilaments

double helix polymer of actin, possesses directionality and aids cell movement

centrioles

found in the centrosome of animal/plant cells, organize spindle fibers for movement, made up of microtubules

homologous chromosomes

similar but not identical, one from each parent

Centromere

constricted regions on chromosomes where sister chromatids are attached

metacentric centromere

centromere in the middle

submetacentric centromere

centromere is slightly off center

acrocentric centromere

centromere is near one end

telocentric centromere

centromere at end of chromosome

p arm

short arm of chromosome

q arm

long arm of chromosome

locus

the site on homologous chromosomes where a precise gene is located

karyokinesis

nuclear division of genetic material to daughter cells

Cytokinesis

division of the cytoplasm

interphase

Cell grows, performs its normal functions, and prepares for division; extended and uncoiled chromatin

G1 phase

The first gap, or growth phase, of the cell cycle, consisting of the portion of interphase before DNA synthesis begins

G2 phase

The second growth phase of the cell cycle, consisting of the portion of interphase after DNA synthesis occurs.

G0 phase

a nondividing stage where the cell is still metabolically active

S phase

committal phase, dna is replicated (2N to 4N)

Prophase (mitosis)

centrioles divide and move apart to form spindle fibers, establish poles while chromosomes condense

Prometaphase (mitosis)

period of chromosome movement where they are clearly doubled and the centrioles have forms spindle fibers at the poles

Metaphase (mitosis)

chromosomes align at the equatorial plate and marking the site where the cell will divide

Kinetochore

proteins associated with centromeres that allow fibers to bind and enact migration

Cohesin

protein complex that holds sister chromatids together

Separase

enzyme the degrades cohesin for seperation

Shugoshin

protein that protects cohesin from degradation until the correct time

Sister chromatids

Replicated forms of a chromosome joined together by the centromere

Anaphase (mitosis)

chromatids separate and migrate to the poles

Telophase (mitosis)

chromatids reach opposite poles and begin to uncoil while the nuclear envelope reforms and fibers disappear

Middle Lamella

plant cell dividing wall after mitosis

cleavage furrow

animal cell dividing mechanism after mitosis

G1 checkpoint

checks for cell size, nutrients, growth factors and DNA damage

G2 checkpoint

main mitosis checkpoint, checks if DNA replication has occurred, go ahead signal triggers mitosis

M checkpoint

spindle assembly checkpoint, if chromosomes aren't aligned apoptosis will occur

cyclins

regulatory proteins that bind to kinases that push stages in the cell cycle by phosphorylating target proteins

tumor

mass of rapidly dividing cells that can damage surrounding tissue

cancer cells

non-differentiated cells that enter the cell cycle repeatedly and have enlarged nuclei, fail to undergo apoptosis

contact inhibition

a process that stops additional cell growth when cells become crowded