DAT BIOLOGY – Flashcards

1. all living things are composed of cells 2. cell is the basic fundamental unit of life 3. chemical reactions of life take place inside the cell 4. cells arise from pre-existing cells 5. cells carry genetic information in the form of DNA - passed from parent to daughter cell

- dense structure in the nucleus where ribosomal RNA synthesis occurs

- network of membrane- enclosed spaces invloved in the transport of materials throughout the cell, particularly those materials destined to be secreted by the cell

- receives vesicles and their contents from the smooth ER, modifies them, repackages them into vesicles and distributes them to the cell surface by exocytosis

- power house of the cell - ATP synthesis

- streaming movement of the cytoplasm within the cell

- membrane bound sacs, transport and storage of materials that are ingested, secreted, processes or digested by the cell

- microtubule involved in spindle organization during cell division, not bound by a membrane - PLANT CELLS DO NOT CONTAIN CENTRIOLES

- membrane bound vesicles - contain hydrolytic enzymes - cellular digestion

- composed of microtubules and microfilaments - gives cell mechanical support - maintains shape - functions in cell motility

- hollow rods of tubulin - support, provide framework for organelle movement - cilia and flagella- specialized arrangements of microtubules

- solid rods of actin - cell movement and support - move material across plasma membrane ( contraction phase of cell division, amoeboid movement)

- kinetic energy spreads small suspended particles throughout the cytoplasm of cell

- Brownian movement - cyclosis/ streaming - ER

- Diffusion - Circulatory system

- growth, chromosome replication - cell spends 90% of time here - after replication, chromosomes consist of two identical sister chromatids held together at centromere - individual chromosomes are not visible - DNA is uncoiled (chromatin) - G1, S, G2

- active growth phase - cell size increases - protein synthesis

- DNA synthesis

- cell prepares to divide - grows and synthesizes proteins

- nuclear division

- Cellular division

- chromosomes condense - centriole pairs separate and move to opposite poles -spindle forms - nuclear membrane dissolves

- centriole pairs are at opposite poles - fibers of spindle attach to chromatid and kinetochore - spindle fibers align the chromosomes in the middle (METAPHASE PLATE)

- centromeres split, each chromatid has own centromere- sister chromatids separate - sister chromatids pulled to opposite poles- shortening spindle fibers

- spindle apparatus disappears - nuclear membrane forms - each nucleus contains same number of chromosomes - chromosomes uncoil

- cleavage furrow

- produce two intermediate daughter cells - N chromosomes and sister chromatids

- chromatin condenses into chromosomes - spindle forms - nuclei and nuclear membrane disappear -Homologous chromosomes come together- SYNAPSIS - crossing over may occur

- homologous pairs (tetrads) align at metaphase plate -each pair attaches to a separate spindle fiber at the kinetochore

- homologous pairs separate, pulled to opposite poles (disjunction) - Random mixing of maternal and paternal origin - Medelian Law

- nuclear membrane forms around each new nucleus - sister chromatids still joined at centromere

- chromosomes align at equator, separate and move to opposite poles, surrounded by new nuclear membrane - new cells are haploid * in women, only one of these daughter cells becomes a functional gamete, other 2 or 3 destroyed by body

- cellular ingestion is a function of the cell membrane and vesicles. - cell membrane- invaginates around a food particle and pinches off, enclosing the material in a vesicle that cant ravel freely in the cytoplasm- ENDOCYTOSIS

- lysosomes, vesicles and mitochondria - lysosomes- contains hydrolytic enzymes, it fuses with a vesicle alowing its enzymes to chemically degrade the ingested material - glucose is metabolized in mitochondria via aerobic respiration

- ER- forms a long, interconnecting series of passageways through which proteins are transported - Smooth ER- secretes proteins into cytoplasmic vesicles that are transported to the Golgi - microtubules are involved in the transport of proteins in some specialized cells (neurons)

- prokaryotes: genetic material is composed of a single circular DNA localized in the nucleoid - Eukaryotes: highly coiled linear strands of DNA organized into chromosomes within a membrane-bound nucleus

-PROKARYOTES: occurs directly at the cellular membrane -EUKARYOTES: Mitochondria

-PROKARYOTES: do NOT contain membrane bound organelles -EUKARYOTES: contain membrane bound organelles (nucleus, lysosomes, vesicles, ER and mitochondria)

E. A and B DNA and Ribosomes

- protects the cell from the hydrolytic actions of the enzymes it contains.

- play an important role in cell division - make up the mitotic spindle, responsible for separating sister chromatids - during prophase, radial array of microtubules forms around centrioles - push the centrioles to opposite poles of the cell, forming the bipolar spindle apparatus - when chromosomes align at the metaphase plate, these spindle fibers attach to the centromeres - during anaphase, the fibers shorten and pull on the centromeres, separating the sister chromatids and moving them to opposite poles of the cell

- after anaphase, actin filaments and myosin filaments under the cell membrane contract, leading to the indentation of the membrane at the metaphase plate and the subsequent division of the parent cell into two daughter cells

ANAPHASE

PROPHASE

ANAPHASE

PROPHASE

PROPHASE

METAPHASE

TELOPHASE

-metaphse of mitosis, replicated chromosomes line up in a single file - during anaphase- sister chromatids separate and move to opposite poles of the cell - Metaphase I- homologous pairs of replicated chromosomes line up - anaphase I- the homologous chromosomes separate, but sister chromatids remain attached to eachother

- Adenine - Guanine - 2 rings

- Cytosine - Uracil - Thymine - 1 ring

- 2

- 3

- Removes primer - need RNA primer to begin replication

- relieves super coiling

- continually synthesized by DNA Pol - needs only one primer

- synthesized discontinuously (Okazaki fragments) - fragments put together by ligase - needs several primers

- UAA - UAG - UGA

- genetic information goes from DNA to RNA to protein

- break down large chemicals and release energy

- build up large chemicals and require energy

- building up of new tissues from digested food materials

- entrance of air into the lungs and gas exchange between alveoli and the blood

- includes the exchange of gas between the blood and cells and the intracellular processes of respiration

- high energy hydrogen atoms are removed from organic molecules (oxidative phosphorylation)

- 3 phosphate groups next to each other - negatively charged Oxygen- high electrostatic energy

Glucose + 2 ADP +2Pi + 2NAD+ -----> 2pyruvate + 2ATP +2NADH +2H+ + 2H2O

- yeast and some bacteria - pyruvate (from glycolysis) converted to ethanol

- fungi, bacteria, muscle cells (strenuous activity) - when 02 supply to muscle cell lags behind the rate of glucose catabolism, pyruvate generated is reduced to lactic acid - NAD+ is regenerated when pyruvate is reduced

- 36 to 38

-loses CO2, acetyl group remaining transferred to Coenzyme A into acetyl CoA - NAD+ is reduced to NADH

2 acetyl-CoA + 6NAD+ + 2FAD + 2GDP + 2Pi +4H2O ----> 4CO2 +6NADH + 2FADH2 + 2GTP + 4H+ +2CoA

- 2 ATP

-3 ATP

- 32 ATP

Location: Cytosol (anaerobic) Uses: Glucose, 2ATP, NAD+ Produces: 2 Pyruvate, 4ATP (2ATP net), 2 NADH

Location: Cytosol (anaerobic) Uses: Pyruvate Produces: Lactic Acid or Ethanol + CO2, NAD+ (to reenter glycolysis

Location: Mitochondrial matrix (aerobic) Uses: Pyruvate Produces: Acetyl CoA, NADH

Location: Mitochondrial matrix (aerobic) Uses: Acetyl CoA Produces: NADH, FADH2, GTP (ATP)

Location: Inner Mitochondrial Membrane Uses: NADH, FADH2, O2 Produces: 34 ATP, NAD+, FADH

enzyme and substrate are a perfect match

Substrate induces conformational change to resemble transition state

- High temp: can cause denaturation of enzyme - Acidic/Basic pH: inactivation of enzyme - Concentration of Substrate and Enzyme - Co-Factors: inorganic molecules (ex. Fe in hemoglobin) - Co-Enzymes: organic molecules (ex biotin)

1. Helicase unwinds the DNA, and gyrase uncoils the DNA to prevent breakage. 2. An RNA primer + DNA polymerase then jump on the open 3' end. 3. aOn the leading strand, there is only one open 3' end, so the polymerase synthesizes the entire piece of DNA. 4.On the lagging strand, we get segmented strands, as there are always new 3' ends exposed and new polymerases starting. 5. This leads to the formation of Okasaki fragments. These fragments are then pieced together by DNA ligase. - DNA synthesis is a semi-conservative process: each final helix is made of one parent and one daughter DNA strand

- Helicase unwinds the DNA. - RNA polymerase binds to promoter region (TATA box). - RNAP transcribes the template strand only in a 5' to 3' manner to create hnRNA (pre-mRNA) that must then be processed before being exported to the cytoplasm

1) Splicing: Exons are Expressed, Introns are In between and therefore removed. 2) A methylguanine cap is added to the 5' end to prevent degradation of the mRNA. 3) A poly-A tail is added to the 3' end to prevent degradation of the mRNA. 4) The mature mRNA now exits nucleus via nuclear pores.

1) Initiation: ribosome attaches; tRNA recognizes the start codon (AUG) with its anticodon and brings in the first amino acid (in eukaryotes that's methionine). 2) Elongation: ribosome moves to the next codon; a new tRNA recognizes the codon with its anticodon and brings in a new amino acid. A peptide bond is then formed between the amino acids by peptidyl transferase. 3) Termination: when the ribosome encounters a stop codon (UGA, UAA, UAG), the tRNA that comes in is bound to no amino acid, so no peptide bond is formed, the protein is released, and the ribosome releases the mRNA.

Genotypic ratio: 1 AA: 2 Aa : 1 aa Phenotypic ratio: 3 dominant: 1 recessive

Genotypic ratio: too complex to memorize Phenotypic Ratio - 9 : 3 : 3 :1 9 dominant for both traits 3 dominant for A, not B 3 dominant for B, not A

1) Use & Disuse: organs used extensively will grow; organs not used will atrophy 2) Acquired characteristics: traits acquired during a lifetime can be passed onto offspring

Survival of the fittest: the traits (alleles) of an organism that survives long enough to product the most offspring will become more prevalent in a population. It's just a matter of statistics. Note that fittest doesn't mean strength but rather virility.

1) Fossils: incomplete record but with unifying trends 2) Comparative anatomy: analyzing structure/function Homologous: same anatomy & origin, different functions (bird arms v. human arms) Analogous: same function, different origin & pattern of development (bird wings v. insect wings) 3) Comparative Embryology: similarities in development after zygote formation 4) Comparative Biochemistry: genome sharing and the fact that organisms have similar enzymes/processes 5) Vestigial structures: lost ancestral function 6) Biogeography: natural barriers create evolutionary adaptations (ex: island biogeography)

Independent development of similar structures on unrelated organisms due to ecological pressures (analogous structures)

: Emergence of new species from same precursor (think homologous structures)

Different species that share a common ancestor evolve similarly under similar evolutionary pressures

Different species evolve together because they depend on each other. For example, the evolution of a humming bird's beak and a flower to fit the shape of the beak.

1. Random Mating 2. No natural selection 3. No migration or emigration 4. Large population 5. No mutations

(prokaryotes, such as bacteria)

unicellular eukaryotes or multicellular colonies of eukaryotes without specialized cells, such as algae

multicellular organisms with specialized cells that can perform photosynthesis

unicellular or multicellular eukaryotes with cell walls made of chitin instead of cellulose, which is present in plants. They are sometimes decomposers and include yeasts

animals are multicellular eukaryotes with specialized cells that lack cell walls. They are also usually mobile

1) Primary: where ATP is directly used to build a gradient 2) Secondary: where one gradient is used to build a different gradient

C6H12O6 + 6 O2 ? 6 CO2 + 12 H2O + 36 ATP

- failure of homologous chromosomes to separate properly during meosis I OR - the failure of sister chromatids to separate during meosis II - results in trisomy (down syndrome. monosomy

- may occur spontaneously OR - be induced by environmental factors - chromosome that loses fragment is said to have a deficiency

- inability to produce the proper enzyme for the metabolism of phenylalanine

- RBC become crescent shaped because they carry defective hemoglobin - substitution of valine (GUA or GUG) for glutamic acid (GAA or GAG) - single base-pair substitution

- foreign chromosome fragment (plasmid) is incorporated into the bacterial chromosome via recombination - creating new inheritable genetic combinations

- sexual mating in bacteria - transfer of genetic material between two bacteria that are temporarily joined

- occurs when linked genes are separated - occurs by breakage and rearrangement of adjacent regions of DNA when organisms carrying different genes or alleles for the same traits are crossed

- evolution of new species - groups of individuals that can interbreed freely with each other but not with members of other species - gene flow is impossible between different species

- natural selection - mutation - assortive mating -genetic drift - gene flow

- changes in the composition of the gene pool due to chance - more pronounced in small or new populations (FOUNDER EFFECT)

- migration of individuals between populations will result in a loss or gain of genes - thus changing the composition of a population's gene pool

- have no known current function, but apparently had some ancestral function

- chemosynthetic bacteria

- green plants and phytoplankton

- yeast

- amoebas, earthworms and humans

- involves adaptive responses to the environment

- simplest of learning patterns - involves the suppression of the normal response to stimuli - repeated stimulus results in decreased responsiveness to that stimulus

- pairing unconditioned (food) and conditioned (bell) stimuli to create a conditioned response (salivating @ bell) - Pavlov's dogs

- using punishment (shock) and reward (food) to change behavior

- visual signals used to communicate with other individuals - ex. deer tais, mating displays

- Hierarchy within a community

- Defending an area against individuals from the same or other species

- chemical signals used to communicate within a species

- one species benefits while the other is unaffected - ex. remoras and sharks

- both species benefit - ex. hummingbirds and flowers

- one species benefits while the other is harmed - ex. plasmodium and humans

- one species feeds on another

- include desserts, grassland, rainforests, deciduous forests, coniferous forest, taiga, tundra and polar

- lake, river, and wetland

- species able to colonize a barren area, allowing other organisms to follow - ex. lichens and algae

- a fully established community in equilibrium

- consists of populations of different plants and animal species interacting with each other in a given environment

- A group of organisms of the same species living together in the same location

- interaction between living biotic communities and the nonliving environment

- include all portions of the planet that support life: atmosphere, lithosphere, hydrosphere

- any group of similar organisms that are capable of producing fertile offspring

- acidity (pH) - texture - minerals (phosphates, nitrates)

- functional role of an organisms in its ecosystem - different from habitat - describes what the organism eats, where and how it obtains food.. -no two species can ever occupy the same nice in the same location

- manufacture their own food - green plants

- cannot synthesize their own food - depend on autotrophs or other heterotrophs in the ecosystem to obtain food and energy

- relations between species

- autotrophic green plants and chemosynthetic bacteria

- animals that eat green plants - cow, grasshopper and elephant

- eat primary consumers - ex. carnivores (frogs, tigers, dragonflies)

- feed on secondary consumers - carnivres

- saprophytic organisms and organisms of decay (bacteria and fungi)

- elemental nitrogen is chemically inert and cannot be used by most organisms - the nitrates are absorbed by plants and are used to synthesixe nucleic acids and plant proteins - animals eat the plants and synthesize specific animal proteins from the plant proteins - nitrogen locekd up in waste and dead tissues is released by the action of bacteria of decay which can convert the proteins into ammonia

- receive less than 10 in or rain/year - small plants and animals inhabit the desert - desert plants conserve water actively (cactus, sagebrush, mesquite) - desert animals live in burrows (insects and lizards) - Ex. Sahara in Africa and the Gobi in Asia

- low rainfall (10-30 in/yr) - no shelter for herbivorous animals from carnivorous predators - land animals have developed long legs and hooves - ex. prairies east of the Rockies, steppes of the Ukraine and the pampas of Argentina

- jungles - characterized by torrential rains - tropical rainforests: high temps - climax communities with dens growth of vegetation that does not shed leaves - vines and epiphytes - monkeys, lizards, snakes - tropical: Central Africa, Central America - Temperate: North and South America

- cold winters, warm summers and moderate rainfall - beech, maple, oaks and willow trees (shed their leaves during the cold winter months) - animals: deer, foxes, woodchucks

- cold, dry, inhabited mainly by trees that do not lose their leaves (firs, pine and spruce) - vegetation has evolved adaptations for water conservation - extreme northern parts of the US and souther Canada -Animals: beavers, beers sheep, squirrels and birds

- less rainfall than temperate forests - long, cold winters - are inhabited by trees that do not lose their leaves (spruce) - thin soil covered in moss and lichens - moose and deer

- treeless - froze plain found between the taiga and the northern ice sheets - ground is covered in snow and ice for much of the year - very short summer and growing season, ground becomes wet and marshy - lichens, polar bears, arctic hares

- surrounded by the polar ice caps - frozen areas with no vegetation and few terrestrial life - penguins, polar bears

- region exposed at low tides that undergoes variations in temperature and periods of dryness. - algae, sponges, clams, snails

- region on the continental shelf that contains ocean (depths 600 ft) - algae, crabs, crustaceans

- open seas - divided into photic and aphotic zones

- sunlit layer (250-600 ft) - plankton, nekton, fish, sharks, diatom

- beneath the photic zone - receives no sunlight - only heterotrophs exist here - nekton and benthos -habitat is fiercely competitive

- Individuals from any given population vary from one another in many characteristics (due to mutations). - Genetic variations can be inherited. - Members of a population produce more offspring than the environment can support (causes competition). - Those individuals whose inherited characteristics fit them best to their environment are likely to leave more offspring than less fit individuals. - Over many generations of natural selection, the favorable changes (adaptations) are perpetuated in the species. Accumulation of these favorable changes eventually results in speciation.