Diversity Exam 1

Lateral Gene Transfer

When genetic material moved between organisms without sexual reproduction

how prokaryotes can exchange information without sexual reproduction

Complicates phylogenies based on DNA seq

The more related we are the —— genetic similarity we have and vice versa

more

What was first widely compared to find genetic similarity

rRNA - ribosomal DNA.

Variation in Prokaryotes

Found everywhere.

can be spheres, rods or spirals.

Most accurate measure of relatedness is

how similar genomes are

Variation in Prokaryotes

Single Celled but often live in colonies

Reproduce by fission (asexual) but can exchange genetic material

Prokaryote Environment variation

to some oxygen is poison to others they need oxygen .

photoautotrophs

responsible for converting earth’s atmosphere to aerobic in ancient past.

Cyanobacteria perform…..

photosynthesis

light is used to drive chemicals reactions that build sugars.

chloroplasts in plants are evolved from symbiotic cyanobacteria

Photoheterotrophs

harvest energy from light but rely on sugars made by other organisms

Chemoheterotrophs

Feed on other organisms

Decomposers

break down dead bodies

return carbon to soil and atmosphere

sulfur and N

Nitrogen Fixers

Convert N2 from atmosphere to NH3

Nitrifying Bacteria

NH3→ NO2→ NO3

avaialbe to plants for amino acids, nucleic acid synthesis

Denitrifying

convert organic nitrogen to N2

how to Prokaryotes cause disease

• invade the body

• evade immune system

• multiply

• produce toxins

  • endotoxins

  • exotoxins

Endotoxins

host ecposed when bacteria lyse ( breakdoen of outer membrane)

symptoms: fever vomiting diarrhea

Exotoxins

released by living bacteria

highly poisonous or fatal

Viruses

composed of protein-coated DNA or RNA, encoding a small number of proteins

Virus Classification based on

Nucleic acid type - RNA or DNA

Positive Sense RNA Viruses

the Genome is also template for translation

common cold

polio

covid

Negative sense RNA virus

genome is NOT template for translation but it’s complement

when infect RNA- dependent RNA polymerase make complementary strand, which is then used as a template for translation

rabies

mumps

ebola

RNA retrovirus

protein component includes reverse transcriptase → DNA

so-called proviral DNA is integrated into host’s genome

Vertebrate animals

HIV

DNA viruses

Smallpox

herpes

Bacteriophage - viruses that infect bacteria

how virus increases in number

• spike protein binds cell surface receptor - enters cell

• particle sheds outer proteins, allows direct translation of RNA plus production of more copies of viral RNA to be translated to make viral proteins

• viral proteins are processed and aggregate on rough ER with virus genomic RNA, further processing in golgi

• release of mature viral particles via vesicles that fuse with cell membrane (exocytosis)

Features of Eukaryotes

• organized nucleus

  • linear chromosomes

  • membrane-bound

• organelles

  • Mitochondia

  • Chloroplasts

  • Digestive Vacuoles

Organelles

membranes associated with specialized functions

Vesicles

move materials out of cell, into cell

movement for Eukaryotes relies on….

cytoskeleton

• predation

• change shape

• increased size

all Eukaryotes have a —— life cycle

sexual - except for rotifers

sex increased diversity

multicellular organisms

cells stay together after cell division

• opportunity for specialization/ increased efficiency

• greater size

• mortal

ex →plants animals fungi

Protist

• single celled

• diverse polyphyletic

• move by flagella, cilia, or pseudopods

Opisthokonts

group of Eukaryotes

• flagellum is posterior, single

• animals- multicellular

• fungi- uni or multi

• choanoflagellates- can be colonial- firsts step toward multicellylarity

Fungi

• cell wall of chitin

• multi or unicellular

• absorptive heterotrophy

• can feed on living or dead organisms

• infections in animals hard to treat bc fungicides are also toxic

absorptive heterotrophy

• secretes enzymes breaks down food then absorbed.

Amboebozoans

• use pseudopods for motility

• aquatic - frishwater

• eats via phagocytisis

• predator, scavenger, or parasite

example amoeba

• aquatic lobosean

• no parasites.

Phsaryum- plasmodial slime mold

• terrestrial

• not multicellular

foraminiferans

• single cells with external shell of calcium carbonate

• source of limestone

radiolarians

phagocytosis

a process by which cells engulf and digest large particles, such as bacteria, dead cells, or other debris

Rhizarians

• unicellular

• aquatic

• long pseudipids

• marine

ex - foraminiferans, radiolarians

Archaeplastids

• land plants

• multicellular

• Chlorophyll

ex - red algae,

green algae

Stramenopiles

• unequal flagella

• can be uni or multicellular.

• can be photosynthetic

ex diatoms , brown algae.

Endosymbiosis

• Where one organism (endosymbiont) lives inside another organism(host)

• first clue - more than one membrane surrounding chloroplast

Serial Endosymbiosis

• more than 2 membranes around

• a dude eats a dude who has eaten a dude

Ex- brown algae, diatoms

Alveolates

• sacs under cell membrane

• single celled

ex paramecium , plasmodium dino flagellates

Excavates

• unicellular

• often lacking mitochondia,

ex- giardia euglena

What is an Animal?

• Multicellular

  • cells adhere after miotic division

  • cells communicate with eachother

• heterotrophic

• internal digestion

• motility

  • muscles, nerves, skeleton

Heterotrophic

• eats other organisms

Animals are ….

monophyletic

• common ancestor thought to resemble colonial choanflagellates

Sponges

• earliest and simplest animals are marine

• lack tissues- groups of sim cells acting as one

• Body form: cup-shape

• inner surface composed of choanocytes

  • flagella beat to draw water through pores to the central cavity

Dipoblastic animals

2 body layer

• distinct organ systems

• central gastrovascular cavity

  • single opening is both mouth and anus

  • tentacles trap prey, sweep into mouth

• noncentralized nerve net

• aquatic - body supported by water

3 major animal clades

Lophotrochozoans

ecdysozoans

deuterstomes

lophotrochozoans

• common larval form, feeding apparatus

  • bryozoans, molluscs, annelids

• prostomes

• have lophophore - feeding structure

• trochophore - free-living larval stage

ex molluscs, annelids, flatworms, rotifers, bryozoans

ecdysozoans

• shed exoskeleton to grow

  • anthropods, nematodes

• protostome

• ex - tardigrades, nemoatodes

Deuterostomes

• mouth forms second

  • echinoderms, hemichordates, vertebrates

Anthropods

a type of ecdysonzoans

a protostomes

ex - crustaceans(lobster)

hexapods(grasshopper)

what makes an anthropod succesful ?

• Body supported by an exoskeleton (chitin, hard but flexible)

• segmented body plan (metameric)

• paired, joined appendages

multicellular

more than one type of cell

multicellularity First step:

colonial organisms

• multiple cells adhere but are not different

2 billion years ago

1.8-1.3 bya

1.2 bya

1360-635 mya

500 mya

no terrestrial life

1st eukaryotes marine

protist, bacteria on land

1st multicellular organisms

1st terrestrial multicellular organism

what invaded land first ?

fungi then plants then animals

what are inventions of terrestrial life

• roots

• stems/lignin

• vascular tissue

• exoskelton

• veins muscles nerves

• amniotic eggs **

Land plants are in what family

Archaeplastids

Vascular tissue what is the advantage?

cells specialized for tansport of fluids allowed increased in stature

What is the advantage of leaves ?

specialized organ for photosynthesis

advantage of root?

uptake of water and mineral s

sporphyte

produces cells that undergo meiosis

• products of meiosis called spores

gametophyte

• produces gametes

  • devolps from spores.

alternation of gens varies between —— and ——- plants

vascular. nonvascular plants

nonvascular plants

Dom- gametophyte.

• small live in moist environments

  • mosses

  • liverworts

  • hornworts

Vascular plants

• tracheids conduct water over long distances.

  • allows for greater size

  • structural support against gravity

• Dominant sporophyte

• most have true roots

• some reproduce using seeds

• seedless vascular plants have other primitive characteristics

The first Vascular plants

• stem only—> theyre photosynthetic

• no leaves or roots

  • rhizoids hold in place = underground stems

• stem branches at tip

  • equal split / dichotomous

• repoduce by producing spore in sporangia

2 origin of leaves

flattened, sterile sporangia —> microphylls

Fusion of side branches —> megaphylls (true leaves)

Green algae

chlorophyll a and b like land plants

multi cellular

sea lettuce.

diatoms

• single celled. silica in cell walls upper an dlower like a petri dish

• live in fresh and salt water

• photosynthetic storage products

• earth filtration

brown algae

multi cell - sea palms gian kelo

photosynthetic

chlorophyll A. C brown pugments

source of emuslifier for ice cream

obligate anaerobes

oxygen is poison to them.

live in 02 free zones

obligate aerobes

requires o2

facultative anaerobes

can use 02 or anaerobic respiration