exam 2

Discipline: Biology (and other Life Sciences)

Type of Paper: Question-Answer

Academic Level: Undergrad. (yrs 3-4)

Paper Format: APA

Pages: 1 Words: 275


Biology/Introduction To Biology

Chromatin   composed of DNA and proteins, condenses into chromosomes when cell is about to divide

karyotype  displays chromosomes

autosomes  22 pairs

interphase   period of time between cell divisions

S DNA Synthesis  chromosome now composed of 2 sister chromatids

G2  double everything

M phase   division of nucleus and cytoplasm

Mitosis    most cells undergo, 1 cell division, 2 daughter cells, genetically identical.

mitosis phases
prophase - desenigrate
metaphase - all lined up
anaphase - pulled apart
telophase - physical division of cytoplasm

cytokinesis  division of cytoplasm

checkpoint   delay the cycle until all is well

mutations  due to diff. environmental assaults can result in abnormal growth in cells.

angiogensis  formation of blood vessels

meiosis  formation of cell gametes/sex cells, 2 cell divisions, 4 daughter cells, not genetically identical.

synapsis  homologous chromosomes line up side by side

crossing over  during synapsis, homologues sometimes exchange genetic material

polypoid  eukaryote 3 or more set of chromosomes

aneuploid   organism that doesnt have exact multiple of diploid # of chromosomes

monosomy  1 type of chromosome

trisomy  3 type of chromosomes

non disjunction   failure of homologues to separate in meitosis

deletion  end of chromosome breaks off

duplication  certain chromosome segment more than once in same chromosome

translocation    movement of chromosome segment to 1 chromosome to another.

mendel (scientist)  used pea plants for genetic experiments

monohybrid crosses
examine only 1 trait
TT - Homozygus Dominan
Tt - Heterozygus
tt - Homozygus Recessive

law of segregation  each individual has 2 factors for each trait. factors separate during formation of sex cells.

genotype   alleles pairing

phenotype  physical trait

dihybrid cross   true breeding plants differed in 2 traits. 2 possible outcomes.

law of independent assortment  independently (w/ out reguard to how the others separate)

rules of probability   flipping a coin. no memory

pedigree  determine whether a condition is recessive or dominant.

autosomal recessive
tay-sachs disease - uncontrollable seizures
cystic fibrose - common lethal genetic diseases, thick mucuss
PKU - metabolic disorder, affecting nervous system
sickle cell - heart failure

autosomal dominant
neurofibromatosis - brown splotches
huntington disease - degeneration of brain cells
achondropasic - dwarfism

incomplete dominance
heterozygote, intermediate phenotype

both dominant genes are expresed equally

single gene has more than 1 effect

nucleic acid
contain only nucleotides molecules that are composed of a nitrogen base, phosphate, A pentose (5 xarbon sugar)

contains deoxyribose C-G. A-T

contains ribose C-G A-U

DNA replication
occurs during S phase in nucleus. process of copying a DNA molecule. each strand unwinds and serves as template for new strand.

each strand is half old and half new

DNA replication steps
complementary base pairing

helicose  unzip DNA molecule

DNA polymerose    adds complenmentary base pairing, rejoins the DNA molecule

Transcription  in nucleus, DNA turn into mRNA

Translation   in cytoplasm, mRNA turn into amino acid/polypeptide

splicing  introns (non coding) section removed leaving only exons (coding)

alternative mRNA splicing  increases possible # of protein products that can be made from a single cell

RNA   joins with proteins to form ribosomes

transfer RNA (tRNA) tranfers amino acids to the ribosomes

end binds to correct codon

point mutations   change in single DNAa nucleotide, sickle cell

frameshift mutation  insertion or deletion of 1 or more nucleotides

reproductive cloning   desired end is a individual that is exactly like original

therapeutic cloning  desired is mature cells of various cell types that could be used to treat human illness

gene cloning done to produce many identical copies of the same gene

gene pharming   use animals to produce pharmaceuticals. therapeutic and diagnostic proteins are injected into animals DNA and proteins appear in the animals milk.

xenotransplanation  use of animal organs in humans

gene therapy   insertion of foreign gene into human cells for treatment of a disorder

coding DNA   2 percent of genome, only exons are incorporated into mRNA

non coding DNA  98 percent of genome. introns intervening sequences or regulators of gene expression.

functional genomics  understand the exact role of genome in cells or organisms

proteomics  study of structure, function & interaction of cellular proteins.

bioinformatics app. of comp. technologies to the study of biological ....

comparitive genomics   compare the human genome to the genome of other organisms

natural selection  aspect within enviroment chooses members of the population w/ the advantages phenotype to reproduce more than the other members.

components of natural selection
memebers of a population have inheritable variations.
a population is able to produce more offspring than enviroment can support.
only certain members of pop. survive and reproduce.
nat. selection results in a pop. adapted to the local enviroment.

evolution  changes in pop. overtime due to the accumulation of inherited diff.

fossils  evidence for evolution,  traces of past life.

sedimentations  recognizable layer in several layers

common ancestor  1 couple can give rise to many descendants

transitional fossil  closely related to the common ancestor

anatomic similarities
homologous structure - anatomically similar, inherited from a recent common ancestor.
analogous structures - no common ancestor, not constructed similarly

comparitive anatomy  vertebrate, forelimbs used for flight, swimming.

vestigial structures   fully developed in group of organisms but non functional in other groups

SNP  why we all look different

biogeography   study of plants and animals in diff. places in the world.

gene pool   population composed of all alleles in all individuals making up population

hardy - weinburg equilibrium   no evolution taking place

nonrandom mating  when only certain genotypes or phenotypes mate w/ 1 other

gene flow  movement of alleles

genetic drift   changes in alleles frequencies in gene pool due to chance

bottleneck affect  prevents majority of genotypes from participating in next generation

founder effecf   establish new population somewhere else

stabilizing selection  intermediate phenotype is favored

directional selection  extreme phenotype is favored

disruptive selection  2 or more extreme phenotype is favores

macroevolution   requires origin of species

speciation    splitting 1 species into 2 or more, or transforming into new species

evolutionary species concept   members share distinct evolutionary pathway

polyploidy  chromosome # beyond the diploid #