biology i spring 2015 semester exam review- key

Biology I Spring 2016 Semester Exam Review

Gel electrophoresis

• A process used to identify a person based on their DNA

• Can be used to solve crimes or match children with parents

Unit 7- Biotechnology

• DNA is broken into segments using restriction enzymes

• Smaller fragments travel further than larger segments

• The segments are compared to sample DNA to identify people

cloning

• process of producing genetically identical individuals

• Can occur artificially

• occurs in nature when organisms such as bacteria, insects or plants reproduce asexually


Restriction enzymes

• Enzymes that cut a DNA molecule at a particular place.

• The enzyme "scans" a DNA molecule, looking for a particular sequence, usually of four to six nucleotides. Once it finds this recognition sequence, it stops and cuts the strands.

• On double stranded DNA the recognition sequence is on both strands, but runs in opposite directions. This allows the enzyme to cut both strands.

• Most plasmids used for recombinant technology have recognition sequences for a number of restriction enzymes. This allows a scientist to choose from a number of places to cut the plasmid with a restriction enzyme.


***used for gel electrophoresis and for biotechnology involving recombining DNA

DNA fingerprint

• The result of gel electrophoresis


*the DNA from the crime scene would be from suspect 2

Plasmid

• It is a circular piece of DNA that acts as a vector (a carrier of the gene).

• We get them from bacteria

• it attaches to the gene that is to be genetically engineered. It allows the gene to be carried to a host cell to be replicated producing many identical genes.

• To cut open the plasmid requires an enzyme called restriction endonuclease and to stick the gene into the plasmid requires an enzyme called ligase.


Transgenic organism

• An organism that has a gene from another organism transferred into their genome

• An organism that results from DNA recombination


Be able to distinguish between gene and chromosomal mutations

• Gene mutation is a small-scale alteration of the genetic material of an organism, which primarily is a change in the nucleotide sequence of a particular gene. (frameshift and substitution)

• Chromosome mutation is a large-scale alteration of the chromosomes of an organism, where either the number or the structure of chromosomes is changed. (duplications, inversions, and deletions)

• If the question shows actual nucleotides (ATGC) then we are talking about the gene; if it shows alphabetical letters (ABCDE) then we are talking about the chromosome


Know how gel electrophoresis works to separate DNA

• The smaller segments travel farther

• An electrical current moves the segments


Know how restriction enzymes cut DNA

• A restriction enzyme cuts at a certain combination of nucleotides

• For example, this enzyme cuts at AATT


*The enzyme will always cut at the same combination, and a person’s DNA stays the same, so this can be used to identify a person because the same sized DNA fragments will be cut every time

Binomial nomenclature

• Two named system for naming organism

• Genus species

• Genus is capitalized, species is lowercase

• Both names are italicized

Unit 8- Evolution and Classification

*this helps scientists communicate because organisms have different names in different languages, as well as nicknames in the same language

Natural selection

• The gradual process by which heritable biological traits become either more or less common in a population

• This is based on whether the traits offer reproductive success to an organism so the organism can pass it on to the next generation

• It is a key mechanism of evolution.


Directional selection

• One extreme phenotype is selected over the other

• In other words, one trait is much more favored than the other


Stabilizing selection

• Pressure is on the two extremes so the intermediate phenotype is favored

• In other words, it’s better to be average in this type of selection


Disruptive selection

• The extreme phenotypes are favored over the intermediate phenotype

• In other words, the average population is not special and doesn’t have a trait needed to survive


Vestigial structure

• A leftover structure from an organisms genetic ancestors

• Like the appendix in a human or the pelvis and femur in a whale


Mnemonic: think of a tacky 90s vest; it’s leftover and not needed anymore (don’t nobody need that vest)

Analogous structure

• Structures with similar functions but different genetic origins and different underlying structure

• This is NOT a sign

of a common

ancestor


Mnemonic: think of an analogy in English; bird is to birdwing as butterfly is to butterfly wing (they do the same job)

Homologous structure

• Structures with similar genetic structures but different functions

• This is a sign of a common ancestor


Mnemonic: homo means same; they have the same basic structure

Comparative embryology

• Compares and contrasts embryos of animals

• Used to show how animals are related


Aerobic

• Needing oxygen to carry out functions (survive)

• Organisms didn’t become aerobic until there was oxygen in Earth’s atmosphere

• Led to a greater variety of life on earth


Endosymbiosis • an evolutionary theory that explains the origin of eukaryotic

cells from prokaryotes

• Organelles like mitochondria and chloroplasts were taking in from free-living bacteria into another cell


Chemosynthesis

• Converting chemicals into food

• This, and photosynthesis, are the two ways autotrophic organisms make their own food


Speciation

• the evolutionary process by which new biological species arise


• Reproductive isolation can lead to new species arising • Populations can’t mate • Populations become adapted to their own environment

Adaptation

• A trait that allows an individual to survive better than other individuals it competes against in its environment


Paleozoic era

• When multicellular organisms first appeared

• 544-248 million years ago

• The earliest of the 3 eras


Mnemonic: paleontologists study very old things; this is the earliest actual era

Mesozoic era

• Age of reptiles

• 248-65 million years ago

• The middle era


Mnemonic: meso means middle

Cenozoic era

• Mammals radiated and diversified

• 65 million years ago – present

• Humans evolved recently


Mnemonic: C for Cenozoic; c for current

Be able to use a dichotomous key Unit 8- Evolution and Classification

Hardy-Weinberg equilibrium • Equilibrium state in which genotype frequencies in a

population stay the same from generation to generation

• If a population is in Hardy-Weinberg equilibrium, it is NOT evolving


Know the five requirements for a population to be in Hardy-Weinberg

equilibrium

• No genetic drift (caused by a large population)

• No gene flow (caused by not emigration or immigration)

• No new alleles added to gene pool (no mutations)

• No sexual selection (caused by random mating)

• No natural selection (all traits equally aid survival)


Know what each term stands for in:

p2 + 2pq + q2 = 1

• P is the dominant allele

• Q is the recessive allele

• p2 is homozygous dominant (TT)

• 2pq is heterozygous (Tt)

• q2 is homozygous recessive (tt) • The point of the equation is to see if the next generation has

the same frequency of alleles as the previous. If everything is the same, there is no evolution.


Be able to identify selection graphs

• Directional- one extreme is favored (C)

• Stabilizing- intermediate phenotype is favored (B)

• Disruptive- extreme phenotypes are favored (A)


Know the hierarchy of classification

• Does King Phillip Come Over For Good Spaghetti?


Know the three geological eras

• Precambrian was super early life

• Paleozoic- life moves onto land

• Mesozoic- age of reptiles

• Cenozoic- mammals radiated


Know the approximate age of the earth

• 4.6 billion years


Capsid

• Protective covering that protects the genetic material

• Protein shell

Unit 9- Viruses and Bacteria

Capsid/Capsule/Viral Envelope mnemonics

• Flat Stanley represents viral DNA because it is not living

• Flat Stanley wears a cap(sid) right on top of himself (DNA)

• SOMETIMES, Flat Stanley (wearing his cap) gets put inside an envelope

• Major Tom is living (bacteria)

• “now it’s time to leave the capsule if you dare” –David Bowie

• Capsule surrounds living bacteria, capsid surrounds non-living virus

Bacteriophage

• a virus that infects and replicates within a bacterium

• Attaches and injects DNA into bacteria


Envelope (of a virus)

• lipid bilayer that contains viral proteins, usually including the proteins that enable the virus to bind to the host cells


Lytic cycle

• Virus infects cell, replicates, and bursts from cell (known as lysing)

• Lysing kills the host cell


Lysogenic cycle

• The viral DNA attaches to the cell’s DNA and is replicated when the cell replicates

• Does not kill the cell

• Eventually the cell will leave the lysogenic cycle and enter the lytic cycle


Antibiotic resistance

• Overuse- using antibiotics when bacteria are not causing illness (ex: using antibiotics to treat the flu, which is viral)

• Underuse- failing to take the entire course of antibiotics may kill the weak bacteria and let the stronger bacteria survive to replicate

• Misuse- when antibiotics are used for other reasons besides bacterial illness (ex: giving antibiotics to livestock to prevent illness)


Pathogen

• Something that can cause infectious disease

• Viruses and bacteria

• “germs”


Endospore

• a dormant, tough, and non-reproductive structure produced by certain bacteria

• Endospore formation is usually triggered by a lack of nutrients (food, oxygen, etc.)

• Allows bacteria to survive harsh conditions

• stripped-down, dormant form

to which the bacterium can reduce

itself


Penicillin

• An antibiotic

• Widely used to kill many types of bacteria

• Saved millions of lives and increased life expectancy


Conjugation

• the transfer of genetic material between bacterial cells by direct cell-to-cell contact or by a bridge-like connection between two cells

• Use pili to transfer genetic material


Binary fission

• A form of asexual reproduction

• How bacteria (prokaryotes) reproduce


Retrovirus

• A virus with RNA instead of DNA

• Replicates inside a cell using reverse transcriptase to make DNA from RNA

• HIV is a retrovirus


Reverse transcriptase

• The protein that makes DNA from RNA

• Often we refer to it as the process of making DNA from RNA


Be able to identify parts of a virus Unit 9- Viruses and Bacteria

Be able to compare the structure of a virus to that of a cell

• Virus are non-living

• Simple; no organelles


Know how HIV infects individuals and replicates

• HIV infects cells and replicates in the lysogenic cycle

• When it enters the lytic cycle and begins lysing, the cells are destroyed and a person has AIDS

• Helper T cells are destroyed


Distinguish between the lytic and lysogenic cycles

• In the lysogenic cycle the viral DNA is replicated when the cell replicates- the host cell lives

• In the lytic cycle the virus breaks out from the cell (lyses) and kills the host cell


Know what type of organism antibiotics kill

• Bacteria only


Know the beneficial effects of bacteria

• Provide nutrients (live in digestive systems, make vitamins, break down food, ferment food)

• Fix nitrogen (convert nitrogen to ammonia for plants to use)

• Benefit ecosystems (photosynthesize, recycle carbon, nitrogen, hydrogen, and sulfur)

• Bioremediation (break down pollutants like oil spills and other biodegradable materials)


Know the general characteristics of Kingdom Archaebacteria and Kingdom Eubacteria

• Archaebacteria – single-celled prokaryotes, typically live in extreme environments

– “ancient bacteria”

– Can withstand high temperature and high amounts of salt, and very acidic or very basic environments

• Eubacteria – More modern bacteria

– Can photosynthesize and live in oxygen

• Similar because both are single-celled prokaryotes , both have pili, plasmids and flagella

• Different because bacteria cell walls are made of peptidoglycan, archaea have membranes that are made of many different lipids


Describe the environment in which archaea live

• Live in harsh environments

• high temperature and high amounts of salt, and very acidic or very basic environments

• They don’t all need oxygen to survive


Gametophyte

• Haploid (n) phase of the plant life cycle

• Often spores created by plants

• This phase is before fertilization occurs

Unit 10- Plants

Sporophyte

• Diploid (2n) phase of the plant life cycle

• A fertilized seed, and then a plant

Unit 10- Plants

Haploid

• N number of chromosomes

• Half the usual amount

• Usually what results from meiosis

Unit 10- Plants

Diploid

• 2n number of chromosomes

• Regular amount of chromosomes

• Chromosome pair, one from each parent

• The number of chromosomes in a body cell

Unit 10- Plants

Nonvascular

• Does not have a vascular system

• Grows close to the ground to absorb water and nutrients

• Ex: liverworts, hornworts, mosses

Unit 10- Plants

Vascular

• Have a vascular system to transport water, nutrients, and food (sugars)

• Adaptation that allowed plants to grow off the ground

Unit 10- Plants

Phloem Unit 10- Plants

• Vascular tissue that transports sugars throughout the plant

• Osmosis moves water from xylem to phloem, which helps move sugars through the phloem

• Sink: storage area (such as fruit or root) where excess sugars are stored

Xylem Unit 10- Plants

• Vascular tissue that transports water and dissolved nutrients from the roots up through the plant

• Uses the process of transpiration to create a vacuum to pull water up against gravity

Stomata

• Holes in the lower epidermis of the leaf that open and close, allowing gas exchanges

• Stomata close at night because photosynthesis isn’t occurring

• Stomata also close if the plant is drying out too quickly

Unit 10- Plants

Gibberellins

• Hormones that produce dramatic increases in size

• Starts germination and growth of seedlings

Unit 10- Plants

Auxin

• Hormone involved in lengthening cells

• Controls some forms of tropism like phototropism

Unit 10- Plants

Cytokinins

• Stimulate cytokinesis (cell division)

• Involved in lateral growth (growth of side branches)

Unit 10- Plants

Ethylene

• Hormone that causes ripening of fruit

Unit 10- Plants

Deciduous

• A tree that sheds its leaves annually

Unit 10- Plants

Gravitropism

• A plant response to gravity

• In germinating seeds, roots grow down and stems grow up

Unit 10- Plants

Thigmotropism

• Plant response to touch

• Ex: tendrils of vines grow in coils around anything they touch

Unit 10- Plants

Phototrophism

• Plant response to light

• Plant cells on shaded side grow longer due to auxins. This bends the plant toward the light.

Unit 10- Plants

Transpiration

• Evaporation in plants

• Water escapes through the stomata

• The process creates a vacuum which pulls water up through the xylem

Unit 10- Plants

Know the characteristics of nonvascular and vascular plants

• Non vascular grow towards the ground to absorb water

• Non vascular have no vascular system

• Vascular plants have a vascular system

• Vascular plants can grow off the ground

Unit 10- Plants

Be able to describe the organism from which plants evolved

• Green algae

• Algae are not plants; plants are not algae

Unit 10- Plants

Know the alternations of generations

• Plants have 2 generations, gametophyte (haploid) and sporophyte (diploid)

Unit 10- Plants

Know the material of the plant cell wall

• cellulose

Unit 10- Plants

Be able to label Unit 10- Plants

Know the function of the xylem Unit 10- Plants

• Vascular tissue that transports water and dissolved nutrients from the roots up through the plant

• Uses the process of transpiration to create a vacuum to pull water up against gravity

Know the function of the phloem Unit 10- Plants

• Vascular tissue that transports sugars throughout the plant

• Osmosis moves water from xylem to phloem, which helps move sugars through the phloem

• Sink: storage area (such as fruit or root) where excess sugars are stored

Know how auxins work to cause plant stems to bend toward light

• Hormones that stretch the side of the plant that is in the shade, causing the plant to bend towards the light

Unit 10- Plants

Know the function of root hairs

• Root hairs increase the surface area of the roots and allow for more water to be absorbed

Unit 10- Plants

Peristalsis

• a series of wave-like muscle contractions that moves food to different processing stations in the digestive tract

• Begins in

esophagus

Unit 11- Human Body Systems

Villi/microvilli

• Tiny protrusions and folds in the small intestine that increase the surface area of the small intestine so more food absorption can take place


Axon terminal

• Part of a neuron

• The area through which the impulse leaves


Dendrite

• Part of the neuron

• The part that receives the impulses


Homeostasis

• Keeping internal environments within set ranges

• “keeping the body in balance”


Gametogenesis • Production of gametes (sperm and eggs)

• Meiosis is the main part of gametogenesis


Know the difference between mechanical and chemical digestion

• Mechanical is physical digestion. Chewing physically breaks up food.

• Chemical involves chemicals. Stomach acid and bile continue to break down food. Enzymes in saliva also begin to break down food.


Know the function of the villi/microvilli

• Increases surface area of small intestine to absorb more nutrients


Know how a nerve impulse travels from one neuron to the next

• An electrical impulse is sent from the cell body down the axon and to the axon terminal

• The gap between one neuron and the next is called a synapse

• Electricity does not cross the synapse!

• Chemicals called neurotransmitters send the signal across the synapse to the dendrites of the next neuron

• The electrical impulse starts again and sends

it down the next neuron


Know the primary location of nutrient absorption

• The small intestine does the nutrient absorption

• Specifically, the duodenum absorbs a lot


Know the individual units that proteins, carbohydrates and fats get broken into

• Proteins break into amino acids

• Carbohydrates break into monosaccharides or simple sugars like glucose

• Fats break into lipids


Know the basic functions and the major components of the following systems

• Digestive

• Circulatory

• Nervous

• Respiratory

• Skeletal

• Muscular

• Excretory

• Endocrine


Circulatory Respiratory

• Respiratory system takes in oxygen and expels carbon dioxide and water vapor

• Alveoli in the lungs are the location of gas exchanges with the blood stream

• The circulatory system pumps blood to the lungs to get oxygen (pulmonary), then pumps it to the rest of the body to be used in cellular processes (systemic)

Digestive System

• Digests food and absorbs nutrients, expels solid waste

• Liver makes bile

• Gallbladder stores bile

• Pancreas secretes insulin

• Small intestine absorbs nutrients

• Large intestine absorbs water

Excretory System • Excretes liquid wastes through sweat, breathing,

and the urinary system

• Kidneys filter blood and maintain homeostasis by maintaining fluid balance

• Nephron is filtering unit of kidney

Nervous System

• Sends signals throughout the body (electrical and chemical)

• Central nervous system is brain, brain stem, and spine

• Peripheral nervous system is all other nerves

Nervous System

• A neuron sends signals from the dendrites, down the axon/myelin sheath, to the axon terminal, and across a synapse

Endocrine System

• Glands produce hormones

• Pituitary and hypothalamus- growth/development (puberty)

• Thyroid- metabolism

• Adrenal glands- adrenaline

• Pancreas- insulin

• Testes- testosterone

• Ovary- estrogen

Be able to distinguish between positive feedback and negative feedback

• Negative feed back counteracts a change and tries to restore homeostasis

– Ex: breathing fast while running, shivering when cold, sweating when wet

• Positive feedback increases a change

– Ex: clotting, childbirth


Know the process of gametogenesis for each sex

• Both sperm and egg are created through meiosis I and II

• 4 sperm are created but only 1 egg is created per gametogenesis process

• (the rest of the cells are

known as polar bodies)


Habitat

• Where an organism lives. Think of this as their environment.

• All the biotic and abiotic factors.

• Their ecosystem

Unit 12- Ecology

Niche

• HOW an organism lives

• This is more than where they live. This is their ROLE in the ecosystem.

• A frog and a bird might live in the same habitat, but they have different roles and impact the habitat in different ways.

• Organisms in different niches are less likely to be in competition for resources (competitive exclusion)

Unit 12- Ecology

Population

• A group of the same species that live in one area

Unit 12- Ecology

Community

• Group of different species that live in an area

• All the plant and animals in an area

Unit 12- Ecology

Ecosystem

• Includes all organisms as well as abiotic factors like soil, climate, water, rocks, moisture

Unit 12- Ecology

Biotic factor

• Living things and one-living things

• Organic things

Unit 12- Ecology

Abiotic factor

• Non-living things

Unit 12- Ecology

Predation

• An organism catches and kills another

Unit 12- Ecology

Mutualism

• A symbiotic relationship where both organisms benefit

Unit 12- Ecology

Commensalism

• A symbiotic relationship in which one organism benefits and the other is unharmed

Unit 12- Ecology

Parasitism

• A symbiotic relationship in which one organism benefits and the other is harmed

Unit 12- Ecology

Trophic level

• Nourishment levels in a food chain

• Important because energy is lost from level to level

Unit 12- Ecology

Range/zone of tolerance

• The entire set of conditions, such as air temperature or soil moisture, under which an organism is potentially able to survive

• If an organism gets out of their range of tolerance, they can die

Unit 12- Ecology

Exponential growth

• Rapid population increase due to abundant resources

Unit 12- Ecology

Biomass

• The measure of the total dry mass of organisms in a given area

• There has to be more biomass at the bottom of the energy pyramid

• More producers than consumers

Unit 12- Ecology

Producers

• Organisms that produce their own food

• In general, we are talking about plants

Unit 12- Ecology

Consumers

• Organisms that consume other organisms

• They can consume producers or other consumers

Unit 12- Ecology

Biodiversity

• The more biodiversity (lots of different species) the more stable an ecosystem is

• The loss of biodiversity can lead species extinction

Unit 12- Ecology

Habitat fragmentation

• A barrier forms within a habitat

• Prevents an organism from accessing its entire home range

• Can split and reduce populations, reducing biodiversity

Unit 12- Ecology

Nitrogen fixation

• Bacteria convert nitrogen into ammonia which plants use to carry out functions

Unit 12- Ecology

Be able to describe the nitrogen cycle

Unit 12- Ecology

• Occurs mainly underground • Bacteria are key players • Convert atmospheric nitrogen into ammonia for plants to use

Know the direction of energy flow in food chains and food webs

• The arrow points in the direction energy is passing

Unit 12- Ecology

Know the 10% rule and where the other 90% of energy goes

• 10% of energy gets passed to the next trophic level

• 90% is lost through heat (metabolic processes)

Unit 12- Ecology

Be able to identify each trophic level on an energy pyramid

Unit 12- Ecology

Be able to recognize different symbiotic relationships

• Barnacles create home sites by attaching themselves to whales. As the barnacle is a filter feeder, it also gets access to more water (and more food) due to the relationship. Whale is unaffected. ---commensalism

• A cuckoo lays its eggs in the nest of the warbler. The cuckoo’s eggs hatch first and the young kick the warbler eggs out of the nest. The warbler raises the cuckoo babies and the warbler babies aren’t hatched. ---parasitism

• Ostriches and gazelles feed next to each other. They both watch for predators. Because the visual abilities of the two species are different, they can each identify threats that the other animal may not see as readily. Both species benefit. ---mutualism

Unit 12- Ecology

Know the stages of primary and secondary succession

• Primary succession

– No life was present before

– Starts on rocks

– Moss and lichens break down the rock and turn it to soil

• Secondary succession

– Life was present before but the area was damaged/destroyed

– Soil is left in tact so plant and animals move back in more quickly

Unit 12- Ecology

Know the different survivorship curves

• The graph is talking about the percent of the population that survives

Unit 12- Ecology

• Type 1 do not die young and reach old age before dying

• Type 2 die off slow and steady throughout

• Type 3 have high infant mortality (so they often have a lot more infants)

Exoskeleton

• Hard outer structure that provides support and protection for the organism

• The shell of an insect or crustacean

Unit 13- Animal Kingdom

Bilateral symmetry

• Body divides equally along one plane


Radial symmetry

• Body arranged in a circle along a central axis


Sessile

• Unable to move from a fixed point

• Ex: mussels attached to rock


Ectothermic

• “cold-blooded”

• An organism that regulates its body temperature by exchanging heat with the environment


Endothermic

• “warm-blooded”

• And organism that produces its own heat through metabolic processes


Acoelomate

• An animal with no body cavity

• Porifera, Cnidaria, Platyhelminthes


Coelomate

• An animal with a body cavity (coelem)


Pseudocoelomate

• An animal with a false cavity

• Nematoda only


Endoderm

• Innermost layer of embryonic development

• Become internal organs


Mesoderm

• Middle layer in embryonic development

• Become muscles and blood


Ectoderm

• Outermost layer of embryo

• Develops into epidermis and nervous system


Posterior

• Toward the rear


Ventral

• Toward the tummy (away from the spine)


Be able to recognize cross sections of body plans Unit 13- Animal Kingdom

Be able to identify the germ layers during embryonic development


Be able to identify the basic anatomy of the earthworm


Be able to identify the basic anatomy of the frog


biology i spring 2015 semester exam review- key

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