question

What is the approximate age of the Earth?

answer

4.5 billion years old

question

Approximately when did the earth's crust form?

answer

4 billion years ago

question

How long ago was the first life on earth estimated to have formed?

answer

3.8 billion years ago

question

How long ago was the first evidence of life on earth seen? How was this seen?

answer

About 3.4-3.5 billion years ago with Prokaryotic fossils made by the layering of sediment

question

Macroevolution

answer

the pattern of evolution over a long period of time

question

When did prokaryotic organisms begin to photosynthesize?

answer

2.7 billion years ago

question

What prokaryotic organism was the first to photosynthesize?

answer

cyanobacteria

question

Explain how Oxygen was first put into the earth's atmosphere.

answer

Cyanobacteria began to split water during its light dependent reaction which produced copious amounts of Oxygen that saturated the earth's water bodies, combing with iron, thus laying down iron ore sediments (iron oxides). Once the iron was used up, Oxygen gas evaporated into the earth's atmosphere.

question

How did the introduction of Oxygen into the atmosphere affect the earth's prevalent anaerobic organisms?

answer

this "poisoned" these organisms

question

Approximately how many years ago did the first single-celled Eukaryotes appear?

answer

2.1 billion years ago

question

Approximately how many years ago did the first multicellular Eukaryotes appear?

answer

1.5 billion years ago

question

Phylogenetic Tree

answer

branching diagram that displays major episodes in the history of life on earth

question

What are the four different conditions/steps that simple cells originated out of?

answer

1. Abiotic synthesis of small organic compounds or molecules (monomers) 2. Abiotic synthesis of polymers 3. Packaging of molecules into Protocells (Protobionts) 4. Origin of the earliest genetic material on earth (RNA) that led to inheritence

question

Oparin-Haldane hypothesis

answer

hypothesis stating that the early earth atmosphere was a reducing atmosphere which allowed for the abiotic formation of simple organic molecules

question

What is the result of Miller and Urey's experiment to test the Oparin-Haldane hypothesis?

answer

results proved that a reducing atmosphere consisting primarily of water, NH3, CH4, and H2 in high temperatures with electrical discharge is ample conditions for the abiotic synthesis of simple organic molecules. (supported the hypothesis)

question

What are some of the other theories on how life originated on earth?

answer

-atmosphere was neutral; areas around volcanoes allowed abiotic synthesis of monomers -hydrothermal vents in the ocean -meteorites struck earth containing simple organic molecules

question

What type of reactions allow for the polymerization of the monomers?

answer

dehydration reactions (synthesis)

question

What caused these monomers to polymerize?

answer

came into contact with clay, rocks, or hot sand which act as catalysts for polymerization

question

Protocells/Protobionts

answer

abiotically derived groups of molecules which achieve self-organization, self assembly, and reproduction.

question

How can some Protocells carry out metabolic pathways?

answer

must be supplied with enzymes

question

What are 3 types of Protocells?

answer

Liposomes, Microspheres, and Coacervates

question

Liposomes

answer

type of protocell consisting of lipid droplets which exhibit self assembly in water and can reproduce, undergo swelling/shrinking, grow by engulfing other liposomes, and split into smaller liposomes.

question

Microspheres

answer

-type of protocell -when amino acids are placed on a hot surface, small proteins form, water is added to cool the solution and these proteins proteins form microspheres -grow by absorbing more protein from solution then dividing when a certain size is reached

question

Coacervates

answer

-type of protocell consisting of droplets that form when solutions of protein, nucleic acid, and polysaccharides are shaken. -catalyze chemical reactions -absorb materials from their environment -secrete product

question

What was the first genetic material?

answer

single-stranded RNA

question

What is the main advantage of single-stranded RNA?

answer

it can replicate itself abiotically

question

single stranded RNA can assemble to form ________.

answer

monomers

question

Single stranded RNA codes for its replication with low error rate, but error result in _______.

answer

variety

question

What kind of form does single stranded RNA take on? Why?

answer

a variety of 3D shapes due to the hydrogen bonding between nitrogenous bases

question

Ribozymes

answer

protein formed by RNA that can catalyze peptide bond formation between amino acids

question

Explain how there is cooperation between RNA and the protein that it catalyzes.

answer

RNA catalyzes the formation of the protein that then catalyzes RNA replication

question

How is natural selection displayed by RNA?

answer

there is natural selection for the more efficient cooperatives between RNA and proteins

question

Eutherians

answer

placental mammals

question

evolutionary trend

answer

a general direction of evolutionary change; continuous change of character within an evolved lineage

question

exaptation

answer

structures that evolve in one context but become co-opted for another function

question

Prokaryotes can be classified based up on what criteria?

answer

cell shape, staining reactions, nutrition/metabolism, specific RNA base sequences

question

What are the various cell shapes of prokaryotes?

answer

rods, cocci, spirilla, vibrios, spriochetes

question

In a gram stain, what species de-stain?

answer

gram negative

question

In a gram stain, what species stay stained?

answer

gram positive

question

Photoautotrophs

answer

photosynthesize using light, carbon dioxide, and water

question

Chemoautotrophs

answer

use carbon dioxide to build organic molecules

question

Photoheterotrophs

answer

use light energy, but cannot use carbon dioxide as their sole carbon source. They use organic compounds from the environment to satisfy their carbon requirements. They use compounds such as carbohydrates, fatty acids, and alcohols as their organic "food".

question

Chemoheterotrophs

answer

unable to fix carbon and form their own organic compounds. They obtain energy by the oxidation of electron donors in their environment.

question

True or False: Prokaryotes can undergo aerobic respiration but not anaerobic.

answer

False! Prokaryotes can undergo BOTH aerobic and anaerobic respiration. (Fermentative or respiratory)

question

Types of polymers which can be digested and metabolized by Prokaryotes.

answer

Basically any kind of organic molecule can be digested and metabolized by Prokaryotes. Some can digest and metabolize petroleum.

question

Genetic recombination

answer

the bringing together of genes from different organisms into a single organism (two parents make a child that contains genes from each parent)

question

Prokaryotes exhibit a ________ transfer of DNA from donor cell to recipient.

answer

unilateral

question

Bacterial conjugation

answer

Genetic recombination in prokaryotes that is accomplished through cellular contact

question

Transduction

answer

Genetic recombination in prokaryotes that is accomplished by viruses.

question

Bacterial transformation

answer

ability of bacteria to alter their genetic makeup by uptaking foreign DNA from another bacterial cell and incorporating it into their own

question

permian extinction

answer

The largest mass extinction in the history of life on Earth; it occurred 250 million years ago, driving up to 95 percent of the species in some groups to extinction.

question

cretaceous extinction

answer

65.5 million years ago; eliminated over 50% of species( including dinosaurs)

question

extremophiles

answer

A prokaryote that lives in an extreme environment. Extremophiles include methanogens, extreme halophiles, and extreme thermophiles.

question

stromatolites

answer

layered rocks that form when certain prokaryotes bind thin films of sediment together

question

endosymbiosis

answer

mitochondria and plastids (chloroplasts and related organelles) were formerly small prokaryotes that began living within another cell

question

Endosymbiont

answer

a cell that lives within another cell known as the host cell

question

How would a heterotrophic host benefit from endosymbiosis?

answer

it could use nutrients released from photosynthetic endosymbiont; an anaerobic host could benefit from endosymbionts that turn the oxygen to advantage.

question

Serial endosymbiosis

answer

A hypothesis for the origin of eukaryotes consisting of a sequence of endosymbiotic events in which mitochondria, chloroplasts, and perhaps other cellular structures were derived from small prokaryotes that had been engulfed by larger cells.

question

Cambrian explosion

answer

A relatively brief time in geologic history when large, hard-bodied forms of animals with most of the major body plans known today appeared in the fossil record. This burst of evolutionary change occurred about 535-525 million years ago.

question

continental drift

answer

motion of continents about Earth's surface on plates of crust floating on the hot mantle

question

adaptive radiations

answer

periods of evolutionary change in which groups of organisms form many new species whose adaptations allow them to fill different ecological roles, or niches, within their communities

question

heterochrony

answer

an evolutionary change in the rate or timing of developmental events (ex: an organism's shape depends in part on the relative growth rates of different body parts during development)

question

How many mass extinctions have occurred in the Earth's history?

answer

Five

question

homeotic genes

answer

master regulatory genes that determine basic features

question

Cocci

answer

spherical prokaryotes. They occur singly, in pairs (diplococci), in chains of many cells (streptococci), and in clusters resembling bunches of grapes (staphylococci).

question

Bacilli

answer

rod-shaped prokaryotes. They are usually solitary, but in some forms the rods are arranged in chains (streptobacilli)

question

Spirilla

answer

Spiral prokaryotes

question

peptidoglycan

answer

a network of modified-sugar polymers cross-linked by short polypeptides

question

Vibrios

answer

comma-shaped bacterial cells.

question

Spirochetes

answer

corkscrew-shaped prokaryotes

question

What are the three most common shapes of prokaryotes?

answer

spherical (cocci), rod-shaped (bacilli), and spiral (spirilla and spirochetes)

question

methanogens

answer

archaebacteria that live in anaerobic environments and produce methane as a by-product of their metabolic processes

question

Archael cell walls contains a variety of polysaccharides and proteins but lack ________.

answer

peptidoglycan

question

What is the difference in location of the peptidoglycan layer of gram-positive and gram-negative bacteria?

answer

Gram-positive bacteria have a cell wall made of the peptidoglycan layer. Gram-negative bacteria have a thinner layer of peptidoglycan that is located between the plasma membrane and the outer membrane.

question

Gram-negative bacteria have an outer membrane that contains _________.

answer

lipopolysaccharides (carbohydrates bonded to lipids)

question

capsule

answer

a sticky layer of polysaccharides or protein that covers the cell wall of many prokaryotes. It enables prokaryotes to adhere to their substrate or to other individuals in a colony.

question

Fimbriae

answer

hair-like structures that are shorter, thinner, and straighter than flagella - used for attachment, not movement (AKA attachment pili)

question

How do prokaryotic flagella differ from eukaryotic flagella?

answer

prokaryotic flagella differ from those of eukaryotes in their molecular composition and their mechanism of propulsion. Prokaryotic flagella are much thinner and are not covered by an extension of the plasma membrane.

question

Endospores

answer

A thick-walled protective spore that forms inside a bacterial cell and resists harsh conditions

question

plasmids

answer

the small, circular segments of DNA that are found in bacteria and that stay separate from the bacterial chromosomes, carry accessory genes

question

halophiles

answer

"salt-loving" archaea that live in environments that have very high salt concentrations

question

What allows prokaryotes to move?

answer

flagella

question

What are the methods of genetic recombination in prokaryotes?

answer

transformation, transduction, and conjugation

question

Earliest Eukaryotes had what 3 life processes?

answer

mitotic, sexual, and meiotic processes

question

Genetic variability originated from _______ _______ of eukaryotic organisms.

answer

sexual cycle

question

Every cell in gametes is ________.

answer

haploid

question

Every zygote is ______.

answer

diploid.

question

Syngamy

answer

Fertilization of an egg and sperm (formation of a zygote)

question

Did the sexual cycle evolve as a reproduction strategy?

answer

No, it evolved as a genetic recombination strategy

question

Haploid cells contain how many chromosomes?

answer

23

question

Diploid cells contain how many chromosomes?

answer

46

question

Karyogamy

answer

the fusion of 2 haploid cells creating a diploid zygote

question

Haploid state is achieved by ______.

answer

meiosis

question

What was the first type of sexual cycle to evolve?

answer

zygotic life cycle

question

What cells can undergo meiosis?

answer

Diploid cells ONLY

question

What type of protists are photosynthetic eukaryotes with cell walls?

answer

Algae-- plant-like protists

question

Classification of Algae is based on what 3 things?

answer

pigmentation, storage polysaccharides, and cell wall components

question

Diatom

answer

-member of the stramenophile group -unicellular plant-like protist (algae) with a glasslike cell wall made of hydrated silica embedded in an organic matrix (said to fit together perfectly like a shoe-box) -yellow to brown in color -reproduce asexually by mitosis most of the year -can reproduce sexually, but is uncommon -store energy in the form of a glucose molecule called laminarin

question

What are the primary producers of most aquatic ecosystems?

answer

Algae

question

Dinoflagellates

answer

-algae belonging to Alveolates group -unicellular -found mostly in marine habitats but also in freshwater -whirl through the water -red tide forms after dinoflagellate bloom -some are bioluminescent

question

Describe how Dinoflagellates can be harmful.

answer

Some secrete toxins. When these forms becomes too abundant (usually during a red tide), it can cause massive fish kills. Humans can get poisoning if eat shellfish that have been feeding on these blooms. Example of harmful dinoflagellate: Pfisteria piscidia

question

Zooxanthellae

answer

type of beneficial dinoflagellate that lives in a mutualistic relationship with coral

question

Golden Algae

answer

-AKA Crysophytes -ex: Vaucheria -algae belonging to the stramenophile group -color results from yellow and brown carotenoids, carotene and xanthophyll accessory pigments -most unicellular, some are colonial, some form cyst stages -live in both freshwater and marine environments -similar life cycle to water molds

question

Dinobryon

answer

a freshwater colonial golden algae

question

Brown Algae

answer

-AKA Phaeophyta -protist of the stramenophiles -largest multicellular algae and the most complex -have a thallus comprised of leal-life blade section, stem-like stipe, and root-like holdfast. (NOT homologous to higher plant organs) -flagellated sperm -example: Laminaria (demonstrates alternation of generations)

question

Pneumatocyst

answer

synonym for air bladder, a swollen hollow structure in brown algae, increases buoyancy

question

Red Algae

answer

AKA Rhodophyta -protist with presence of red pigment called phycoerytherin -live at great depths, most common in tropical water, can be found in freshwater environments in soils -have sperm that rely on water currents for movement

question

Green Algae

answer

AKA Chlorophyta -two groups: Chlorophytes and Charophytes -algae most like plants in pigmentation and photosynthetic apparatus -some unicellular and some multicellular/colonial

question

What life cycle is also called the alternation of generations life cycle?

answer

Sporic Life Cycle

question

Trend in plant evolution has been towards reduction of the _______ stages.

answer

haploid (or gametophyte)

question

Diplomonads

answer

-Primitive Eukaryote of the Excavata clade -lack functional mitochondria but have mitosomes instead that help it gain some energy via glycolysis -have multiple flagella and 2 equally sized nuceli -example: Giardia intestinalis (attacks animal intestines causing extreme diarreah)

question

What are the three types of protists?

answer

algae (plant-like), Protozoans (animal-like), and Fungus-like protists

question

water mold

answer

-heterotrophic fungus-like protist -example: Phytophthora (cause of Irish Potato Famine) -essentially goden algae that have lost capacity for photosynthesis -most are decomposers that grow as cottony masses on dead algae and animals in mainly freshwater habitats -white rusts and downy mildews live on land as plant parasites -have multinucleate filaments known as hyphae -mainly diploid

question

Current evolutionary thinking that the water molds evolved from the _______ algae.

answer

golden

question

Spirogyra

answer

a filamentous green alga with spiral chloroplasts. It accomplishes syngamy by conjugation. The haploid filaments merely grow close to each other and a conjugation bridge grows across. The protoplast of one cell crosses this bridge into the other cell to establish the zygote.

question

Ulva

answer

"sea lettuce" -produces nearly identical looking (isomorphic) sporophyte (2n) and gametophyte (n) generations -exhibits the sporic life cycle

question

Chara

answer

believed to have given rise to plants. They have similarity in chloroplast DNA, ribosomal RNA, and some nuclear genes. They are the only green algae with peroxisomes, and their cell wall structure is most similar to that of higher plants.

question

Volvox

answer

colonial sphere of many green algae; flagellated; gametes for differentiation

question

Chlamydomonas

answer

(of the motile colony series aka volvocine line) single biflagellated cells with a single "cup-shaped" chloroplast. Gametes are just like vegetative cells. Can form protective coating around itself in bad conditions.

question

What is the structural difference between the cell walls of archaea and bacteria?

answer

Bacteria's contain peptidoglycan that Archaea's lack

question

What technique is used to classify many bacterial species into two groups based on differences in cell wall composition?

answer

Gram Stain

question

What is the difference between cell wall composition of Gram-positive and Gram-negative bacteria?

answer

Gram-positive has simpler cell walls with larger amount of peptidoglycan than Gram-negative

question

Where are the chromosomes of prokaryotes stored?

answer

In the nucleoid

question

How many chromosomes are found in a typical prokaryotic cell?

answer

One

question

Plasmids

answer

Small rings of separately replicating DNA found in a typical prokaryotic cell

question

Reproduction in prokaryotes draws attention to what three key features of their biology?

answer

1. They are small 2. They reproduce by binary fission 3. They have short generation times (this is why they can have such large populations)

question

heterocyst

answer

A large, thick-walled cell type in the filaments of certain cyanobacteria that performs nitrogen fixation (when in a low oxygen environment)

question

actinomycetes

answer

filaments bacterium found in the soil. Ex. Streptomyces

question

Bacterial transformation

answer

ability of bacteria to alter their genetic makeup by uptaking foreign DNA from another bacterial cell and incorporating it into their own

question

Bacterial transduction

answer

bacteriophages (viruses that infect bacteria) carry bacterial genes from one host cell to another

question

Bacterial conjugation

answer

DNA transfer from one prokaryotic cell to another via direct contact

question

How do sex pili aid in bacterial conjugation?

answer

The cell donating the DNA uses sex pili to attach to the recipient of the DNA. After contacting a recipient cell, each sex pilus retracts, pulling the two cells together and forming a "mating bridge" that provides an avenue for DNA transfer.

question

F factor

answer

A fertility factor in bacteria -DNA segment that confers the ability to form pili for conjugation and associated functions required for the transfer of DNA from donor to recipient -may exist as a plasmid or be integrated into the bacterial chromosome.

question

HFR

answer

High Frequency Recombination-Bacterial strains that can transfer their chromosome because they have an F-plasmid integrated into their genome

question

Cells containing the F plasmid, designated F+ cells, function DNA ______ during conjugation.

answer

donors

question

Cells lacking the F factor, designated F-, function as DNA _______ during conjugation.

answer

recipients

question

R plasmids

answer

bacterial plasmids carrying genes that confer resistance to certain antibiotics

question

Some Cyanobacteria and methanogens convert atmospheric nitrogen to ammonia in a process known as _______ ________.

answer

Nitrogen Fixation

question

Heterocytes

answer

specialized cell that carries out only nitrogen fixation

question

Symbiosis

answer

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

question

mutualism

answer

symbiotic relationship in which both species benefit from the relationship

question

commensalism

answer

symbiotic relationship in which one member of the association benefits and the other is neither helped nor harmed

question

parasitism

answer

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

question

pathogens

answer

parasites that cause disease (many are prokaryotic)

question

exotoxins

answer

proteins secreted by certain bacteria and other organisms

question

Endotoxins

answer

-lipopolysaccharide components of the outer membrane of gram-negative bacteria -don't get released until bacteria dies and cell wall breaks down -example: salmonella

question

Protist

answer

mostly unicellular eukaryote that is not a plant, animal, or fungus (some are colonial or multicellular)

question

What is considered the simplest eukaryote?

answer

single-celled protists

question

mixotrophs

answer

Protists that combine photosynthesis and heterotrophic nutrition

question

Invagination of cell membrane gave rise to what cellular structures?

answer

Endoplasmic Reticulum, Golgi Apparatus, and Nuclear Envelope (created cell with nucleus and endomembrane system)

question

What two structures developed as subsequent changes in eukaryotes organisms?

answer

cytoskeleton and microtubular structures

question

_______ of eukaryotic organisms is an extension of cytoplasm surrounded by plasma membrane.

answer

Flagella

question

What was the subsequent change in chromosomes in Eukaryotic organisms?

answer

changed from a single chromosome to multiple chromosomes that consist of linear DNA with proteins

question

Eukaryotic cells divide by _______.

answer

mitosis

question

The first eukaryotes resulted in the origin of the ________ cycle to accomplish genetic recombination.

answer

sexual

question

The origin of the sexual cycle resulted in the origin of the _____ state.

answer

diploid (2N)

question

Every gamete cell is ______.

answer

haploid (1N)

question

Syngamy

answer

fertilization

question

How is the diploid state achieved?

answer

by syngamy

question

Karyogamy

answer

fusion of 2 haploid cells during syngamy

question

The haploid state of the sexual cycle is accomplished by _______.

answer

meiosis (reductive division of diploid cells)

question

How many sets of chromosomes do haploid cells have?

answer

one (one gene for each protein)

question

Zygotic life cycle

answer

-the only diploid stage is the zygote (cell formed from syngamy) -all other stages are haploid -most likely 1st type of sexual cycle to evolve -many algae and fungi have this type of life cycle

question

Gametic life cycle

answer

-the only haploid stage are the gametes (cells which fuse in syngamy) -all other stages are diploid -this is a typical animal life cycle

question

Sporic Life Cycle

answer

-produces haploid stages in addition to gametes and diploid stages in addition to zygotes -typical of some algae and most plants

question

The trend in plant evolution has been towards the ______ of the haploid (gametophyte) stages.

answer

reduction

question

True or False: Either haploid cells or diploid cells can divide by mitosis.

answer

True! **But only diploid cells can undergo meiosis**

question

gametophyte

answer

haploid multicellular organism (or multicellular haploid stage)

question

sporophyte

answer

diploid multicellular organism (or multicellular diploid stage)

question

Excavata

answer

(the excavates) clade of protists that includes Diplomonads and Parabasalids

question

Parabasalids

answer

-Primitive Eukaryote of the Excavata clade -have hydrogenosomes instead of mitochondria -example: Trichomonas vaginalis (STD)

question

Diplomonads and Parabasalids lack a true functioning _________. They have modified versions of this organelle instead.

answer

Mitochondria

question

Slime mold

answer

Fungus-like protist belonging to the Amoebozoan clade -2 types known as Plasmodial slime molds and Cellular slime molds

question

Plasmodial Slime Mold

answer

-type of slime mold -example: Physarum -brightly colored, often yellow/orange -use cytoplasmic streaming to distribute oxygen/nutrient -has a feeding stage which is a multinucleate plasmodium living in organic matter -plasmodium dries up in harsh condition and forms sporangium for sexual reproduction -sporangium undergoes meiosis forming haploid spores that are flagellated or amoeboid and fuse in syngamy -diploid zygote is formed that undergoes mitosis forming the feeding plasmodium

question

Cellular Slime Mold

answer

-type of Amoebozoan slime mold -example: Dictyostelium -During sexual reproduction, two haploid amoebas fuse to form diploid zygote that consumes haploid amoebas -the giant diploid cell undergoes meiosis followed by mitosis -new haploid amoebas are released -During the feeding stage (asexual reproduction) haploid solitary amoebas act individually -when food is depleted, solitary cells form an aggregate that functions as a unit -aggregate forms a stalk that supports an asexual haploid fruiting body -haploid spores are released -haploid amoebas emerge from the spore coats

question

zoospore

answer

asexual spore that uses a flagellum for locomotion

question

gametangium

answer

cell or organ in which gametes develop

question

archegonium

answer

female reproductive structure in some plants, including mosses and liverworts

question

One of the adaptations of plants to life on land is the formation of a waxy layer known as a _______ on surfaces exposed to air.

answer

cuticle

question

Plants developed supportive tissues like ______.

answer

fibers

question

Plants developed vascular tissues like _____ and ______.

answer

xylem and phloem

question

Xylem

answer

dead hollow cells with secondary cell walls thickened with lignin for transport of water and dissolved minerals upwards and outward

question

Phloem

answer

living cells with only primary cell walls for transport of sugars and other organic matter in all directions

question

Apical meristems

answer

localized regions of cell division at the tips of shoots and roots

question

Bryophytes

answer

non-vascular embryophytes with dominant gametophyte (n) generation

question

The origin of vascular tissue like the xylem and phloem allowed for the development of ________ ______.

answer

specialized organs (roots, stem, and leaves)

question

What is the earliest known vascular plant?

answer

Aglaophyton

question

Phylum Lycophyta

answer

The club mosses -many extinct species which reached the size of modern tress. Only a few, low growing species remain. These have small leaves with only a single unbranched strand of vascular tissue (microphylls).

question

Lycopodium

answer

a homosporous species -sporophyte produces a single type of meiospore which germinates into a gametophyte with both antheridia and archegonia

question

Strobili

answer

sporophyl clusters

question

Selanginella

answer

a heterosporous species -sporophyte produces 2 types of meiospores. Megaspores germinate into female gametophyte which produces only archegonia. Microspores germinate into male gametophyte which produces only antheridia.

Bio 151 Unit 3 – Flashcards

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