Exam 2 Bio112

Describe the difference between a prokaryotic organism and a eukaryotic organism

Prokaryotic organisms do not contain nucleus or membrane bound organelles

Describe the structure of a common Prokaryotic cell and identify its parts

lack of a true, membrane-bound nucleus. Instead of distinct internal compartments, they feature plasma membrane, cell wall, and capsule, inside is cytoplasm which holds nucleoid ribosomes and plasmids, uses flagella to move, fimbriae to attach and pili is used in sexual reproduction

Explain the differences between Bacteria and Archaea

Archaea are known as extremophils, they strive in very extreme environments Halophils means survive high salinity environment, and thermophils means they survive high heat, bacteria is import to human health by forming symbiotic relationships with different eukaryotes the ones we are more familiar with are pathogenic which means they can make us sick

Describe the different phyla of bacteria presented in the lesson

Proteobacteria - huge phylum consisting of gram negative bacteria, some Cyanobacteria - Bacteria that live in freshwater oceans and wetlands that produce oxygen and fix nitrogen, sometimes referred to as green blue algae

To identify bacteria according to its shape and cell wall structure

Coccus - spherical shape, Bacillus - rod shaped, Spirillum - rigid spiral shaped, Comma shaped - vibrios, spirochetes - flexible spiral

Explain what it means to be Gram positive or gram negative and how this influences resistance to antibiotics

Gram positive are purple, have thick peptidoglycan layer and no outer envelope/glycocalyx this means that antibiotics like penicillin can target the peptidoglycan, making them vulnerable

Gram negative are pink/red and have a thinner peptidoglycan layer with an outer envelope, these are more likely to be antibiotic resistant ex. E coli

Describe what an endospore is and explain how it contributes to the survival of prokaryotes

Prokaryotes can form metabolically inactive endospores, which remain viable in harsh conditions for centuries, it protects the cell

Explain what fimbriae and Pili are used for

Fimbria are short hairs that help prokaryotic cells attach to surfaces in their habitat

Pili are longer hairlike structures that aid in exchange of DNA between bacterial cells

Explain how prokaryotes navigate and move around in their environment

The movement towards a stimulus is called taxis, bacteria can detect chemical stimuli in their environment and make movements toward or away from those signals, toward a chemical signal is called positive chemotaxis away from the signal is called negative chemotaxis, they use structures called flagellum to propel themselves through the environment

Describe the methods by which prokaryotes reproduce asexually and sexually.

Asexually - Binary fission, cells duplicate dna and divide into two, identical cells, very fast population, Horizontal Gene transfer: transformation - when cell takes up naked DNA from the environment asexually -

Horizontal gene transfer conjugation - exchange of dna fragments from bacterial cell to another using sex pili

Describe and explain how transduction, transformation and conjunction contribute to genetic diversity of prokaryotes

Genetic recombination occurs when dna is combined from two different sources which leads to diversity, Transduction is a type of horizontal gene transfer that occurs when a Bacterial phage infects a bacterial cell, the resulting cell is now a recombinant cell that contains dna from the donor cell and its own increasing genetic diversity transformation - is when the cell takes naked dna from the environment, increases genetic diversity Conjugation - is direct cell to cell exchange of dna through a pilus, increases genetic diversity

Describe the different nutritional modes and cellular respiration strategies prokaryotes can use

Autotrophs - photoauto and chemoauto get their carbon sources from co2 Heterotrophs - photohetero and chemohetero get their carbon from organic compounds photo = energy come from light Chemo = energy comes from inorganic chemicals for auto and organic compounds for hetero

Explain how prokaryotes become antibiotic resistant

Overusing them gives more opportunity to be resistant Since they reproduce so fast the ones that survive the antibiotics have more offspring and can keep getting more resistant faster

Explain the different roles prokaryotes play in ecosystems

They play the role of decomposers, influence many nutrient cycles like the carbon cycles and nitrogen cycle, developed symbiotic relationships with most living organisms, helping human and insects metabolism

Explain the different ways prokaryotes can be used in Biotechnology.

Uses bacterial strains to express genes of interest for human use or to produce needed substances, E. coli used in gene cloning, CRISPR can alter genes in other organisms, uses to treat HIV infected cells, To make natural plastics, biodegrade oil spills, having them produce biofuels

Describe the different phyla of plants and their defining characteristics

10 different phyla Two phyla groups called vascular and non vascular (bryophytes) Non vascular split into mosses (bryophyta), liverworts (hepatophyta), and hornworts (anthocerophyta) - landplants that are close to the ground, need moist environment as they take in water via osmosis, need water droplets or film to reproduce - have flagellated sperm Vascular plants divided into three sub groups Seedless vascular plants - lycophytes and pteridophytes Non flowering seed plants ( gymnosperms ) - cycads, ginkgos, conifers, and gnetophytes Flowering vascular plants angiosperms

Describe the adaptations that evolved to facilitate the evolution of land plants

Alternation of generations - land plants alternate body forms from having a diploid lifestyle to a haploid lifestyle. Allowed for plants to colonize land and reproduce without being submerged in water Apical meristem - the tips and the roots of growing plants have actively dividing cells where all plant grown occurs, allowed land plants to be able to access the different resources needed for growth on land plants need to be able to grow toward the resources Thick epidermis - land plants have thick tissues that help them withstand desiccation (drying out) and mechanical stress, most plants have cuticle covering leaves to keep water in

Explain what problem land plant adaptations had to solve

Avoiding drying out, getting nutrients, and reproducing without relying on water

Explain what alternation of generations is and how this trait allowed for plants to colonize land

Alternation between haploid ( gametophyte) and diploid ( sporophyte) body forms, allowed plants to take full advantage of environment giving them the ability to reproduce with spores

Describe the different groups of vascular plants

Seedless vascular plants - reproduce using sports and require moist environment Gymnosperms - non flowering seed producing vascular plants Angiosperms - flowering seed producing vascular plants, attract pollinators to ensure fertilization

Look at a plant phylogeny and determine the shared derived traits and ancestral traits for plant phyla

Describe what advantages the evolution of the seed provided to vascular plants.

Allowed for plants to move to harsher environments by protecting the embryo from harsh environmental conditions. The seed can remain dormant, until conditions are right for germination

Explain how the seed contributed to the dispersal of plants further inland into more harsher climates

The seed provides nourishment proteins and energy to the developing embryo within the seed helping it spread further

Describe what advantages the evolution of flowers provided to vascular seed plants

Flowers evolved specific traits to entice pollinators ensuring pollination, animal pollinators travel long distance, flowers contain ovaries that protect the embryo and following fertilization fruits nourish the embryo

Describe the different methods by which flowers are pollinated and fruits are dispersed.

The color and scent of flowers attracts different animals. The shape of the flower also facilitates what type of animal can obtain nectar and spread pollen from flower to flower Clustered flowers attract insect Reduced perinanth - wind pollination Fused petals - accumulate nectar Floral tubes - attracts birds

Explain how plants and their pollinators have coevolved.

Pollinators are attracted to flowers by their color, shape, size and smell, pollinators choose more attractive plant, and then they get pollinated allowing them to survive and carry on Pollinator specificity can be a downfall for both plant and animal, when it gets too specific and one species goes extinct the other will as well

Describe the different phyla of animals and their defining characteristics

9 major phyla - Parazoa ( sponges, aquatic asymmetrical that lack true tissues and organs rely on porous body structure and filter feeding ) ,

cnidaria( soft bodied radially symmetrical posses stinging cells, they have basic nervous system and a single body opening that serves as both mouth and anus)

platyhelminthes (flatworms, bilaterally symmetrical, unsegmented that lack body cavity, possess a gastrovascular cavity with one opening and regenerative abilities,),

Nematoda ( roundworms unsegmented with false body cavity pseudocoelom and complete digestive track)

Annelida (Bilaterally symmetrical animals characterized by ring-like body segmentation and a well-developed, true coelom. They introduce complex organ systems, including a closed circulatory system Mollusca (soft body animals typically possessing a muscular foot for locomotion a visceral mass and a mantle that often secretes a calcium shell )

Arthropoda ( largest and diverse animal phylum insects spiders crustaceans, hard chitinous exoskeleton that is molted for growth, jointed appendages and segmented bodies

echinodermata( sea starts sea urchins, marine invertebrates with radial symmetry and internal skeleton covered in spiny skin, have water vascular system that controls hydraulic tube feet for movement and feeding

Chordata ( vertebrates and invertebrate chordates - organisms that possess a flexible rod like notochord at some stage in their development, feature a dorsal hollow nerve cord, pharyngeal slits or pouches and post anal tail, this group includes all vertebrates

Identify the key characteristics of all animals Interpret a phylogenetic tree of living animals

Heterotrophs: have to ingest food to make energy Cell structure: they lack cell walls and organized into tissues Most reproduce sexually, diploid stage dominates the life cycle, Hox genes : encode as master controls proteins for development, the number and variation of hox genes contributes to animal diversity

Identify the derived traits for each clade on the animal phylogeny

Sponges are the basal animals, Eumetazoa: clade of animals with true tissues , most animal phyla belong to the clade bilateria, 3 major clades of bilaterian animals : Deuterostomia,Lophotrochozoa,Ecdysozoa, Most animal phyla are invertebrates, Chordata is the only phyla that includes vertebrates

Describe the two types of body plans in animals; radial and bilateral symmetry

Radial symmetry - have a top and bottom side, usually sessile or planktonic, they stay still Bilateral symmetry

Interpret the animal phylogeny including the different clades and derived traits.

All organisms in this clade have bilateral symmetry. There are three main groups under bilateria; Lophotrochozoa, Ecysozoa, and Deuterostomia.

Identify the main phyla and describe the characteristics of Lophotrochozoa

7 major phyla - flatworms, rotifers, lophophorates, Mollusks, and annelids Most group either are lophopore: crown of ciliated tentacles or trochophore : distinct larval stage Flatworms - flattened body shape enables them to metabolize without circulator or respiratory system, have a nervous system that sense stimuli and coordinate movements Annelids - segmented worms, they lack a specialized respiratory system so they exchange gases by diffusion

Identify the main phyla and describe the characteristics of Mollusks

Soft unsegmented animals, Mantle : tissue that secretes calcium carbonate shell in most species, foot muscle that provides locomotion Visceral mass : body region that contains digestive circulatory excretory and reproductive organs

Identify the main phyla and describe the characteristics of Ecdysozoa

Consist of nematodes and arthropods, all possess a cuticle or external coat that protects

Identify the main phyla and describe the characteristics of Nematoda

segmented round worms that are not typically visible but very abundant in every environment, cuticle is primarily made of collagen, reproduction is usually sexual with separate males and females, internal fertilization, large number are parasitic examples include pinworms hookworms, tichinella, heartworms

Identify the main phyla and describe the characteristics of Arthropoda

Largest and most successful animal phylum, more that 1 million recorded species of arthropods, jointed appendages, exoskeleton is made of chitin and protein which provides protection and points of attachment for muscles, segmented many segments have appendages for locomotion food handling reproductions, well developed sensory organs

Identify the main phyla and describe the characteristics of Deuterostomia

Third group of bilateral animals it is divided into two groups echinodermata ( all invertebrates) and Chordata (vertebrates and some invertebrates) both groups share patterns in development

Identify the main phyla and describe the characteristics of Echinodermata

Includes sea stars sea urchins and cucumbers Modified radial symmetry, body can be divided into 5 parts, autonomy ability to detach a body part that will later regenerate, external fertilization: male and female individuals release gametes into the water

Describe the key characteristics of all Chordates

notochord a single flexible rod that lies between the digestive tract and nerve cord, dorsal hollow nerve cord in vertebrates this develops into the brain and spinal cord, pharyngeal slits in early chordates : filter feeding device in later chordates it develops into gills for gas exchange Tunicates and lancelets are the only two groups of invertebrates in chordates they do not have cranium or vertebrae

Describe the characteristics of all Vertebrates

Have two or more sets of hox genes : lancelets and tunicates have only one cluster, vertebrae enclosing a spinal cord, an elaborate skull Two classes of jawless vertebrates Class Myxini and class Petromyzontida Class Myxini : hagfish, entirely marine organisms, highly reduced vertebrate skull made of cartilage bottom dwelling scavenger Class petromyzontida : lampreys marine and freshwater most are parasites skeleton made of cartilage

Explain the advantages of a jaw and the groups that have a jaw

Gnathostomes include fish amphibians reptiles and mammals, are jawed vertebrates Jaws enable organism to grip prey firmly which increases capture rate, provided the ability to attack larger prey which opened up more food resources

Explain how the jaw has evolved over time

Primitive jawless fish contained 9 gill arches and 9 gill slits in the mouth, early jawed fish gill larches 1 and 2 were lost and 3 became modified to form hinged jaw, modern jaw fish gill arch 4 also became modified to form a stronger jaw

Explain how tetrapods are phylogenetically related to other chordates

They have the four defining chordate traits, a notochord, a dorsal hollow nerve cord, pharyngeal slits, and a post anal tail

Identify and explain the key adaptations that helped tetrapods move onto land

Four limbs important to support the weight of an animal on land, feet with digits help transmit forces from the muscles to the ground when an animal walks, a neck allows for separate movement of the head, fusion of the pelvic girdle to the backbone provides added strength and shift the weight of the body, ears needed for detecting airborne sounds

Identify and explain the key adaptations of amniotes and the helped them move away from water

Amniotes use a amniotic egg which is a egg filled with fluids, keeps the embryo from drying out and the fluid inside provided and enclosed pond for each individual, dessiccation-resistant skin skin is thicker water resistant and contains keratin, thoracic breathing allows a great volume of air with each breath compared to buccal pumping, water conserving kidney allow a concentration of waste prior to elimination which conserves water, internal fertilization