AP Biology Exam (units 5-8)

CELL CYCLE

cell cycle stages

interphase, mitosis, cytokinesis

interphase

G1 phase, S phase, G2 phase

G1 phase

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

S phase

The synthesis phase of the cell cycle; the portion of interphase during which DNA is replicated.

G2 phase

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

Mitosis

part of eukaryotic cell division during which the cell nucleus divides

-prophase, metaphase, anaphase, telophase

prophase

Chromosomes become visable, nuclear envelop dissolves, spindle forms

Metaphase

Chromosomes line up in the middle of the cell

anaphase

Phase of mitosis in which the chromosomes separate and move to opposite ends of the cell

telophase

After the chromosome seperates, the cell seals off, Final Phase of Mitosis.

Cytokinesis

division of the cytoplasm to form two separate daughter cells

G0 phase

A nondividing state occupied by cells that have left the cell cycle, sometimes reversibly.

cell cycle check points

control mechanisms in eukaryotic cells which ensure proper division of the cell

G1, S, G2, M

G1 checkpoint

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

S checkpoint

checkpoint that determines if DNA has been replicated properly

G2 checkpoint

checks for cell size and DNA replication

M checkpoint

Spindle assembly checkpoint. Mitosis will not continue if chromosomes are not properly aligned.

MPF

mitosis promoting factor

cyclins and cyclin-dependent kinases (cdks)

two types of regulatory proteins involved in cell cycle control

How MPF and cyclins and cdks interact

MPF provides a chemical signal that tells the cell to continue past the G2 checkpoint. MPF is made up of cyclin, a protein encoded by photo-oncogenes, and a kinase which provides energy through phosphorylation for process necessary for successful mitosis. The cyclin breaks down after the cell passes through G2 checkpoint (if it stayed available always, cell would be pushed through G2 checkpoint even if not ready). The kinase does not degrade and instead stays to be reused later on.

cancer

any malignant growth or tumor caused by abnormal and uncontrolled cell division

6 ket mutations:

-unlimited cell growth

-ignore checkpoints

-escape apoptosis

-immortality=unlimited divisions

-promote blood vessel growth

-overcome anchor and density dependence

(2/12 notes)

binary fission

A form of asexual reproduction in single-celled organisms by which one cell divides into two cells of the same size

binary fission steps

1. DNA Replication

2. Chromosome Segregation (when the replicated chromosomes move to different ends of cell)

3. Separation (new plasma membrane growth, cytoplasm divide, and new cell walls form around the new cells)

MOLECULAR GENETICS

chromosomes in prokaryotes

single circular DNA w/ proteins, smaller than DNA of eukaryotes

chromosomes in eukaryotes

multiple and linear

histones

semi-conservative replication

in each new DNA double helix, one strand is from the original molecule, and one strand is new

DNA replication

DNA unzips into two parts and splits with the cell. In it's new home each side of the DNA strand attack to matching nucleotides to create 2 exact copies. It is important in puberty and other times of growth as it is the reproducing of your cells.

3' vs 5' end of DNA strand

replication goes 3'->5'

- 3' (of original molecule) is leading strand

- 5' is lagging strand

RNA primer

A small piece of single-stranded DNA. It acts a signal, binding to and marking the piece of DNA which is to be copied in the polymerase chain reaction (PCR).

DNA primase

synthesis of RNA primer

DNA polymerase

Enzyme involved in DNA replication that joins individual nucleotides to produce a DNA molecule

Okazaki fragments

Small fragments of DNA produced on the lagging strand during DNA replication, joined later by DNA ligase to form a complete strand.

DNA ligase

A linking enzyme essential for DNA replication; catalyzes the covalent bonding of the 3' end of a new DNA fragment to the 5' end of a growing chain.

nuclease

An enzyme that cuts DNA or RNA, either removing one or a few bases or hydrolyzing the DNA or RNA completely into its component nucleotides.

telomeres

DNA at the tips of chromosomes

-protects from losing too many nucleotides during reproduction to cause issues in the cell

telomerase

An enzyme that catalyzes the lengthening of telomeres in eukaryotic germ cells.

-adds to teh 5' end

-different levels of activity in each cell

RNA

single-stranded

ribose

CGAU

DNA

double helix

deoxyribose rugar

CGAT

transcription

(genetics) the organic process whereby the DNA sequence in a gene is copied into mRNA

mRNA

messenger RNA; type of RNA that carries instructions from DNA in the nucleus to the ribosome

RNA polymerase

enzyme that links together the growing chain of RNA nucleotides during transcription using a DNA strand as a template

promoters

region of DNA that indicates to an enzyme where to bind to make RNA

transcription initiation

RNA polymerase attaches to the promoter region of DNA strand, and synthesis begins

transcription elongation

After binding, RNA polymerase unwinds the DNA

Transcription bubble produced

moves with the polymerase as it transcribes mRNA from template strand

within the bubble a temporary RNA:DNA hybrid is formed

transcription termination

When RNA polymerase reaches terminator, transcription stops & RNA chain is released

poly-A tail

Modified end of the 3' end of an mRNA molecule consisting of the addition of some 50 to 250 adenine nucleotides.

postranscriptional modifications

cap on 5' end

poly-A tail to 3' end

splicing

polycistronic genes/alternative splicing

splicing

the process of removing introns and reconnecting exons in a pre-mRNA

translation

Process by which mRNA is decoded and a protein is produced

translation initiation

brings together mRNA, a tRNA with the first amino acid, and the two ribosomal subunits

translation elongation

codon recognition, peptide bond formation, translocation

translation termination

ribosome reads stop codon UAA/UAG/UGA

post-translational modification

Changes to the new protein that may be critical to its final function, like folding, phosphorylating glycosylating, or lipidating

prokaryotic gene regulation

DNA-binding proteins in prokaryotes regulate genes by controlling transcription

lac operon

the operon that controls the metabolism of lactose

trp operon

tryptophan binds to the repressor protein and enables it to repress gene transcription.

epigenetics

the study of environmental influences on gene expression that occur without a DNA change

MENDELIAN GENETICS

meiosis

a type of cell division that results in four daughter cells each with half the number of chromosomes of the parent cell, as in the production of gametes and plant spores.

homologous chromosomes

Chromosomes that have the same sequence of genes and the same structure

-occur after DNA replication

crossing over

exchange of genetic material between homologous chromosomes during prophase I of meiosis

independent assortment of chromosomes

The random distribution of maternal and paternal chromosomes into gametes during meiosis metaphase

Punnett Square

A chart that shows all the possible combinations of alleles that can result from a genetic cross

gene linkage

Traits that tend to be inherited together as a consequence of an association between their genes

Pedigree

A diagram that shows the occurrence of a genetic trait in several generations of a family.

codominace

A condition in which neither of two alleles of a gene is dominant or recessive.

incomplete dominance

A pattern of inheritance in which two alleles, inherited from the parents, are neither dominant nor recessive. The resulting offspring have a phenotype that is a blending of the parental traits.

multiple alleles

A gene that has more than two alleles

pleiotropy

A single gene having multiple effects on an individuals phenotype

epistasis

A type of gene interaction in which one gene alters the phenotypic effects of another gene that is independently inherited.

sickle cell anemia

hereditary disorder of abnormal hemoglobin producing sickle-shaped erythrocytes and hemolysis

AUTOSOMAL RECESSIVE

PLEIOTROPY

Tay-Sachs

autosomal recessive

Huntington's disease

A human genetic disease caused by a dominant allele; characterized by uncontrollable body movements and degeneration of the nervous system; usually fatal 10 to 20 years after the onset of symptoms.

Colorblindness

a recessive x-linked disorder in which an individual cannot distinguish between certain colors

Trisomy 21

condition in which an individual has three number 21 chromosomes, resulting in Down syndrome

NONDISJUNCTION

Klinefelter's

XXY

NONDISJUNCTION

Barr bodies

inactivated X chromosomes found only in females

non-nuclear DNA is transmitted

1. Transformation: 1 bacteria dies and cell wall dies, DNA can be picked up by another bacteria and use it

a. We use it for making insulin

2. Transduction: phage (virus that infects bacteria), sends DNA and makes copies, sometimes escapes and enters bacteria that can make use of it

3. Conjugation: "sex" transfer of plasmid (chromosomal DNA)

environmental factors can influence traits

1. Can affect the histones and turn genes on and off

2. Temperature can affect gene expression

ECOLOGY

innate behavior

an inherited behavior that does not depend on the environment or experience

-fixed action pattern

-biological clocks/rhythms

-communication(pheromones)

-movement

learned behavior

a behavior that has been learned from experience or observation

-imprinting

-spatial learning/cognitive maps

-associative learning

--habituation

--conditioning

-cognition and problem soliving

-social learning

altruism

unselfish regard for the welfare of others

K vs r selected species

exponential growth

unlimited resources

logistic growth

Growth pattern in which a population's growth rate slows or stops following a period of exponential growth

-hit density dependent limiting factors

density dependent limiting factors

limiting factors that are affected by the number of individuals in a given area

density-independent regulation

influence population no matter how big it is (ie natural disasters, new predator, etc)

-random

predator-prey relationship

mechanism of population control in which a population is regulated by predation

symbiosis

A relationship in which two different organisms live in close association with each other

mutualism

A relationship between two species in which both species benefit

Commensalism

A relationship between two organisms in which one organism benefits and the other is unaffected

Ammensalism

relationship when one organism is harmed, the other is unaffected

parasitism

A relationship between two organisms of different species where one benefits and the other is harmed

competition

the struggle between organisms to survive in a habitat with limited resources

keystone species

a species on which other species in an ecosystem largely depend, such that if it were removed the ecosystem would change drastically.

10% rule

Only 10% of the total energy produced at each trophic level is available to the next level. The amount of energy passed up to the levels of the food pyramid reduces as you go up.

GPP

gross primary productivity