AP bio heritary cell communciation

cell communication —> cell to cell contact

thru cell junction: gap junctions (animals) and plasmodesma (plants)

pacrine

short distances communication: local regulate cells in the vicinity of the emitting cells

quorum sensing

used by luminescent bacteria to activate their light emitting genes only when the concentration, in a small area, of bacterial cells is high enough

endocrine signaling

long distances communication to target cells of another cell type —> can reach all parts of the body

autocrine

self communication

signal transduction steps

1. Reception -- ligand binds to receptor causing receptor to change shape

2. Transd­uction -- inform­ation transfer from receptor throughout cell

3. Response -- how the cell changes

Ligand-gated ion channels

Receptors are ion channels that open and let ions cross the membrane

G protei­n-c­oupled receptors (GPCR):

binds to a G protein that can bind to GTP, which is an energy molecule. The GPCR, enzyme and G protein are inactive until ligand binding to GPCR on the extracellular side.

second messengers + Signal transduction cascades

are molecules that relay and amplify the intracellular signal + response

negative feedback

if a system is disrupted, negative feedback mechanisms return the system back to its target set

positive feedback

amplification occurs when the stimulus is farther activated which, in turn, initates can additional responses the produced system change

cell cycle (interphase)

G1: initial growth of the cell, if the cell doesn't not pass this checkpoint, back to G0

S: DNA being copied (replication)

G2: this checkpoint looks for correct DNA replication + final growth phase + if the cell does not pass this checkpoint it may go thru apoptosis

prophase

nuclear envelope beings to disappear, DNA coils into visible chromosomes fibers being to move double chromosomes toward the center of the cell, chromatin condenses + the mitotic spindle being to form

metaphase

chromosmes line up the metaphase plate, fibers align, double chromosomes across the center of the cell

anaphase

fibers separate at the double chromosomes into single chromosmes (chromatids) chromsomes separate at the centromere, single chromosmes (chromatids) migrate to opposite sides of the cell

telopahse

nuclear envelope reappear + establishes 2 separate nuclei each nucleus contains a complete genome, chromosmes will begin to uncoil, 2 daughter nuclei forms

cytokinesis

separate the cell into 2 daughter cells, each containing indentical genomes

purpose of mitosis

The production of daughter cells that are identical copies of the parent cell maintaining the proper number of chromosomes from generation to generation

regulation of the cell cycle —> cyclins

produced to promote cell cycle progression

degraded to inhibit cell cycle progression

regulatin of the cell cycle —> cyclin-dependent kinanses

enzymes

requires cyclin binding for activiation

phosphorylate substrates, promotes certain cell cycle activities

homologous chromosomes

same size and shape, location, and contain the same genes

locus

position of a gene on a chromosome

the law of dominance

when parents with pure, contrasting traits are crossed together, only one form of the trait appears in the next generation —> One trait masks the effects of another trait

The law of segregation

During the formation of gamete, each gene separates from each other so that each gamete carries only one allele for each gene —> each gamete gets only one of the copies of each gene

Independent Assortment

genes for different traits can segregate independently during the formation of gametes —> the allele a gamete receives for one gene does not influence the allele received for another gene

test cross

A genetic cross in which a test organism showing the dominant trait is crossed with one showing the recessive trait; used to determine whether the test organism is homozygous dominant or heterozygous.

linked genes

genes found on the same chromosome, they can’t separate independently . The offspring formed in a recombination event.

x-linked traits (sex linked)

most males get it because they only have one X chromosomes, they will still express the trait even though it’s recessive

Incomplete dominance

blending inheritance (pink flowers)

Codominance

equal expression of both alleles

Phenotypic plasticity

occurs if two individuals with the same genotype have different phenotypes since they are in different environments.

when the calculcated value is high than the critcal value

null hypothesis is rejected