BIOLOGY - CHAPTER 2-3

The two ways to classify viruses

1) Size and shape of capsid, 2) types of diseases they cause.

Explain the structure of viruses

Nucleic Acid (DNA or RNA) + Capsid (made of protein)

Contain no cellular structures (no cytoplasm, or other major organelles), therefore not an organism

How are viruses able to reproduce?

Require a eukaryotic or prokaryotic cells metabolism to

replicate its DNA or RNA and make a protein coat.

what are the two replication cycles?

Lytic cycle and lysogenic cycle

Explain lytic cycle

It occurs in host cell cytoplasm, uses host cell

machinery to copy viral DNA/RNA.

Explain lysogenic cycle

(Provirus): virus enters host cells’ nucleus and

viral DNA becomes part of host cell chromosome. (i.e. herpes

simplex virus)

How are Viruses Spread?

Viruses can be spread through various means such as direct contact, airborne diseases, contaminated water, Vectors (the virus is carried by another species) such as mosquitoes (virus that causes yellow fever) or foxes (rabies).

why viruses would be important for biotechnology

Viruses have the ability to enter host cells and direct the activity of the host cell’s DNA. Genetic engineers are using viruses to introduce specific genes into the host cell.

Explain what a prion is

an abnormal, misfolded protein that acts as an infectious agent by forcing normal proteins in the brain to change their shape and misfold as wel

List similarities between Archaea and Bacteria

both are prokaryotes that lack a membrane-bound nucleus and membrane-bound organelles

List the differences between them.

they belong to separate biological domains and have fundamental differences in their biochemistry, genetics, and cell structures

Explain how bacteria and archaea reproduce asexually and how other genes can get introduced into the genetic material

primarily reproduce asexually through binary fission, and they acquire new genes from other sources through horizontal gene transfer (HGT) and mutations

Explain endosymbiosis

a biological relationship in which one organism (the endosymbiont) lives inside the body or cell of another organism (the host)

Identify the evidence there is to support this theory

This is proven by the organelles having their own bacterial circular DNA, 70S ribosomes, a double membrane, and reproducing independently through binary fission.

Explain the origins of multicellularity

Once eukaryotes appeared on Earth, variety of unicellular forms

evolved, but multicellular forms showed up later…

Based on fossil evidence found in Arctic Rocks, first multicellular

organisms existed 12.-1.5 billion years ago.

Larger complex eukaryotes appeared 550 million years ago

Identify the general characteristics of all protists

they are eukaryotes (their cells have a membrane-bound nucleus and complex organelles), yet they do not fit into the kingdoms of plants, animals, or fungi

Identify distinguishing characteristics and examples of protists at the phylum level

eukaryotic organisms that lack the complex tissue differentiation found in true plants, animals, or fungi.

Explain why biologists can’t agree on the classification of green algae

they do not form a single, isolated evolutionary branch. Instead, they are deeply intertwined with the evolutionary history of land plants, creating a complex web that tears at the seams of traditional classification systems

Identify the 3 phyla of algae and describe characteristics of each phyla

The three major phyla of macroalgae are Chlorophyta (green algae), Phaeophyta (brown algae), and Rhodophyta (red algae

Identify the adaptations that had to evolve for the ancestral green algae to evolve into terrestrial plants

Their evolution is driven primarily by endosymbiosis (when one organism lives inside another), shifting photosynthetic capacity across different branches of the tree of life

Identify all groups of plants and their distinguishing characteristics. Identify examples for each group

1. Bryophytes (Non-Vascular Plants)

• Characteristics: Lack specialized vascular tissues (xylem and phloem); lack true roots, stems, and leaves; gametophyte is the dominant generation; flagellated sperm require water for fertilization.

• Examples: Mosses, liverworts, hornworts.

1. Pteridophytes (Seedless Vascular Plants)

   • Characteristics: Possess vascular tissues (xylem and phloem) with true roots, stems, and leaves; reproduce via spores rather than seeds; sporophyte is the dominant generation; sperm still require water for fertilization.

   • Examples: Ferns, horsetails, club mosses.

2. Gymnosperms (Naked-Seed Plants)

   • Characteristics: Possess vascular tissue; produce "naked" seeds not enclosed inside a fruit (typically borne in cones); pollen carries sperm via wind, freeing fertilization from reliance on water.

   • Examples: Conifers (pines, firs, spruces), cycads, ginkgoes.

3. Angiosperms (Flowering Plants)

   • Characteristics: Possess advanced vascular tissues; produce flowers for reproduction and seeds enclosed within fruits developed from ovaries; undergo double fertilization.

   • Examples: Monocots (grasses, lilies, corn) and Dicots/Eudicots (roses, oaks, sunflowers).

Explain how plants use the alternation of generations. Use the Life cycle of a fern to explain how plants reproduce

• Gametophyte Generation (nn): Multicellular haploid stage that produces haploid gametes (sperm and eggs) via mitosis.

• Sporophyte Generation (2n2n): Multicellular diploid stage that produces haploid spores via meiosis.

Fern Reproduction (Life Cycle of a Fern)

1. Spore Production

   • The mature diploid sporophyte (2n2n) is the dominant fern plant with fronds.

   • Sporangia clusters called sori on the underside of fronds produce haploid spores (nn) via meiosis.

2. Gametophyte Stage (Prothallus)

   • Spores are released into the wind and germinate in moist environments into a small, heart-shaped multicellular haploid gametophyte (nn) called a prothallus.

   • The prothallus develops antheridia (which produce flagellated sperm via mitosis) and archegonia (which produce eggs via mitosis).

3. Fertilization

   • Flagellated sperm require water or moisture to swim from antheridia to archegonia to fertilize the egg.

   • Fertilization combines two haploid gametes to form a diploid zygote (2n2n).

4. Sporophyte Growth

   • The diploid zygote develops by mitosis into a young sporophyte (fiddlehead) that grows out of the gametophyte.

   • The sporophyte matures into a leafy, independent vascular fern plant (2n2n), completing the cycle.

Identify the general structure of Fungi

Fungi are eukaryotic, heterotrophic organisms with rigid cell walls made of chitin.

Identify the nutrition of Fungi

Fungi have a heterotrophic and absorptive mode of nutrition, meaning they cannot produce their own food through photosynthesis and must acquire nutrients from external organic matter

Identify the reproduction of Fungi

Fungi reproduce asexually, sexually, or through both methods depending on the species and environmental conditions.

List the 5 groups of fungus

Chytridiomycota (Chytrids)

Zygomycota (Zygomycetes / Conjugated Fungi)

Glomeromycota (Glomeromycetes)

Ascomycota (Ascomycetes / Sac Fungi)

Basidiomycota (Basidiomycetes / Club Fungi)

What is Chytridiomycota (Chytrids)?

The most primitive group of fungi. They are mostly aquatic and unique because their reproductive cells (zoospores and gametes) have flagella (whip-like tails) to swim in water. Examples: Batrachochytrium dendrobatidis (a fungus that infects and kills amphibians) and Allomyces.

What is Zygomycota (Zygomycetes / Conjugated Fungi)?

Terrestrial molds that form coenocytic hyphae (tubular filaments without internal cross-walls). They reproduce sexually by fusing hyphae to form a tough structure called a zygospore. Examples: Rhizopus stolonifer (black bread mold) and Mucor

What is Glomeromycota (Glomeromycetes)?

A group of fungi that form intimate, mutualistic relationships with the roots of land plants, creating structures called arbuscular mycorrhizae. They help plants absorb water and nutrients from the soil, and they reproduce asexually. Examples: Rhizophagus irregularis (formerly Glomus intraradices) and Gigaspora margarita.

What is Ascomycota (Ascomycetes / Sac Fungi)?

The largest and most diverse group of fungi. They produce microscopic, sac-like structures called asci during sexual reproduction, inside of which spores (ascospores) develop. They can be single-celled or multicellular. Examples: Saccharomyces cerevisiae (brewer's and baker's yeast), Penicillium chrysogenum (the mold that produces penicillin), and morels.

What is Basidiomycota (Basidiomycetes / Club Fungi)?

Advanced fungi that produce club-shaped structures called basidia on their fruiting bodies, where sexual spores (basidiospores) are formed. This group includes many familiar macroscopic mushrooms. Examples: Agaricus bisporus (common button mushroom), Cryptococcus neoformans, and plant rusts and smuts

Define “animal”

A multicellular, eukaryotic organism belonging to the biological kingdom Animalia

Define “invertebrate”

Any animal that lacks a backbone or vertebral column.

Define “vertebrate”

An animal that has a backbone or spinal column made of bone or cartilage

Define “segmentation”

The division of an organism's body plan into a linear series of repetitive parts or sections along its length (from head to tail)

Define “coelom'“

The fluid-filled body cavity in triploblastic animals that sits between the outer body wall and the digestive tract (gut), and is completely lined with tissue derived from the middle embryonic layer, the mesoderm.

Define “blastula”

An early-stage animal embryo that forms as a hollow, fluid-filled sphere of cells.

Define “endoderm”

inner layer produces lungs, liver, pancreas, bladder and stomach lining

Define “mesoderm”

The middle layer produces muscles, blood, kidneys and reproductive organs

Define “ectoderm”

outer layer produces the skin, nerve tissue and some sense organs

What are the characteristics to Classify Animals

1) Levels of organization

2) Number of body layers

3) Symmetry & body plans

4) Body cavity

5) Segmentation

6) Movement

7) Reproduction

8a) Invertebrates, 8b) Vertebrates

Define “porifera”

A phylum of primitive, multi-cellular Merriam-Webster aquatic animals that lack true tissues, organs, a nervous system, or a mouth

Example(s) of porifera

Sponges

Define “cnidaria”

phylum of aquatic, mostly marine invertebrate animals, mobile, have both a mouth and an anus.

Examples of cnidaria

Jellyfish, corals, sea anemones, hydras, and Portuguese man-o'-wars

Define “Platyhelminthes”

A phylum of soft-bodied, invertebrate animals that are dorsoventrally flattened and exhibit bilateral symmetry, can be mobile depending on whether they are free-living or parasitic, have a mouth but no anus.

Example(s) of Platyhelminthes

Free-Living Flatworms, Flukes, Tapeworms

Define “nematodes”

unsegmented, cylindrical, and thread-like invertebrates belonging to the phylum Nematode, mobile, have both a mouth and an anus

Example(s) of nematodes

Hook worm, Pin worm

Define “Mollusca”

A major phylum of soft-bodied, unsegmented invertebrate animals, typically protected by a hard calcium carbonate shell, most mobile, both a mouth and an anus

Example(s) of Mollusca

Octopus, slugs, snails

Define “annelida”

a large phylum of coelomate, bilaterally symmetrical, and segmented invertebrate animals, mobile, mouth and anus

Example(s) of annelida

Terrestrial and Freshwater Worms

Define “arthropoda”

an invertebrate animal belonging to the phylum Arthropoda, which makes up roughly 84% of all known animal species on Earth

what are the sub groups of arthropoda?

Hexapoda (Insects and Allies)

Crustacea (Crustaceans

Chelicerata (Chelicerates)

Myriapoda (Myriapods)

Define “Hexapoda”

The largest subphylum of the phylum Arthropoda, named for its defining feature: six legs (three pairs) attached to the thorax

Example(s) of Hexapoda

True Insects, Class Entognatha

Define “Crustacea”

a large, diverse subphylum of invertebrate animals belonging to the phylum Arthropoda

Example(s) of Crustacea

Blue crabs, hermit crabs, American lobsters, spiny lobsters, Brown shrimp, glass shrimp, Crayfish

Define “Chelicerata”

A major subphylum of the animal kingdom belonging to the phylum Arthropoda

Examples of Chelicerata

Class Arachnida - Spiders, Scorpions, Ticks and Mites, Harvestmen, Camel spiders, Whip spiders and Vinegaroons, Pseudoscorpions

Define “Myriapoda”

Centipedes, Millipedes, Pauropods, and Symphyla

Characteristics of jawless fish

Fish that lack true jaws and have skeletons made of cartilage. This group includes Class Myxini (hagfish) and lampreys.

Characteristics of bony fish

Fish with jaws and skeletons made of true bone. This is the largest group, divided into ray-finned fish (like salmon and tuna) and lobe-finned fish (like lungfish and coelacanths)

Characteristics of Cartilaginous Fish

Fish with jaws and an internal skeleton made of cartilage rather than bone. This group includes sharks, rays, skates, and chimaeras.

Characteristics of birds

Birds are warm-blooded, egg-laying vertebrates that belong to the class Aves and are uniquely defined by having feathers.

Characteristics of amphibians

cold-blooded vertebrates that split their lives between aquatic and terrestrial habitats

Characteristics of reptiles

Reptiles are air-breathing, cold-blooded vertebrates belonging to the class Reptilia, characterized by dry, scaly skin and amniotic eggs.

Characteristics of mammals

Mammals are warm-blooded vertebrates defined primarily by the presence of mammary glands, hair or fur, and three middle ear bones.

How climate change is affecting biodiversity?

Climate change affects it by altering habitats, disrupting ecosystems, and driving species toward migration, disease, or extinction.

Explain what lichen is

a composite organism formed by a close symbiotic partnership between a fungus and a photosynthetic partner.

Define “Zygospores”

A thick-walled, diploid resting spore formed during sexual reproduction in certain fungi (such as zygomycetes like bread mold) and green algae.

Define “spores”

A specialized reproductive or survival cell that can develop into a new individual organism directly without fusing with another cell