Biology Ch. 2 & 3 Test Review PDF

Introduction to Diversity 1. Compare and contrast a. Autotroph vs. Heterotroph b. Asexual vs. Sexual c. Prokaryote vs. Eukaryote a. Autotroph: Make its own food, exist in the first trophic level of the food chain, requires inorganic carbon source, and are independent He...

Introduction to Diversity 1. Compare and contrast a. Autotroph vs. Heterotroph b. Asexual vs. Sexual c. Prokaryote vs. Eukaryote a. Autotroph: Make its own food, exist in the first trophic level of the food chain, requires inorganic carbon source, and are independent Heterotroph: Obtain nutrients from other organisms, exist in the second and third trophic levels of the food chain, requires organic carbon source, and are dependent Same: Both are living things, both require carbon source, and both are part of the food chain b. Asexual: Hyphae extends along the surface and into food, each contains thousands of spores, has two parent cells bacterial DNA is replicated and the cell splits into two identical cells, and reproduction uses gamete cells (meiosis) Sexual: Not common, DNA is transferred between bacteria through a cytoplasmic bridge by a process called conjunction, two genetically different hyphae are produced, has one parent cell, and reproduction does not use gamete cells (mitosis) Same: New offspring is produced, genetic material passed from parent to offspring c. Prokaryote: Has no nucleus, genetic information molecules (DNA) loose in the cytoplasm of the cell, and no complex organelles Eukaryotic: Has a nucleus, genetic information molecules (DNA) are stored in a membrane-bound nucleus, and on average are 100 times larger the prokaryotic cells Same: They both have a cell membrane, have DNA, and have the ability to divide and reproduce 2. The differences between Prokaryotes and Eukaryotes in terms of cell structure and everything. Viruses (2.1) 3. What a virus is. The key characteristics of a virus. Virus: An infectious agent that consists of a nucleic acid either DNA or RNA that is surrounded by a protein coat. Characteristics: - A virus is a tiny, infectious particle; not a cell - They do not fit in the 6-kingdom system - They show very few characteristics of living cells - Viruses need to “commander” living cells (host) to survive and reproduce 4. The characteristics of life viruses have. - Organization - Adaptation - Reproduction 5. The features of viruses. - Very small, 20 - 40 nm in size - Consists of an inner nucleic acid (DNA or RNA) core - Protected by an outer protein coat called a capsid - Some viruses have external membrane envelope - Come in various shapes and affect various organisms 6. The virus categories. - DNA Viruses: Stable, do not mutate rapidly - RNA Viruses: Mutate rapidly, unstable - Bacterial Viruses (Bacteriophages): Infect and replicate within bacteria - Plant Viruses: Infect plant cells - Animal Viruses: Infect animal cells 7. Two reasons why scientists do not consider viruses to be alive. 1. Viruses are unable to produce their own cellular energy or proteins; they must rely on their host for all cellular functions. 2. Viruses can be crystallized, which is common for non-living things. 8. What a capsid is. Capsid: The outer protein layer that surrounds the genetic material of a virus 9. Compare and contrast the lytic and lysogenic cycle. The differences and each step of each cycle explained. Compare and Contrast: Lytic Cycle: Takes over host cell, releases new viruses after 1 generation, and immediate onset of symptoms Lysogenic Cycle: Integrates into host DNA, releases new viruses after several generations, and delayed onset of symptoms Same: Both are initiated by the binding of the virus to a host cell receptor molecule Steps of the Lytic Cycle: 1. Attachment: Proteins on the surface of the virus bind to protein receptors on the surface of the host cell’s membrane. 2. Entry: The virus injects its genetic material (RNA or DNA) into the host cell. 3. Replication: The host cell makes more viral DNA or RNA and proteins. 4. Assembly: New viral particles are assembled. 5. Lysis and Release: The host cell breaks open and releases new viral particles. Steps of the Lysogenic Cycle: 1. Attachment: The virus attaches to a specific receptor on the surface of a host cell. 2. Entry: The viral genetic matter (either DNA or RNA) is injected or enters the host cell. 3. Integration: Instead of immediately replicating itself, the viral DNA integrated into the host cell’s DNA. 4. Latency: The viral DNA remains inactive within the host cell’s genome. The host cell continues to divide, copying both its own DNA and the viral DNA along with it. 5. Activation: Under certain conditions the viral genome becomes active again. It excises itself from the host cell’s DNA and prepares to enter the lytic cycle. Archaea and Bacteria (2.2) 10. Compare and contrast archaea and bacteria. Archaea: Lacks peptidoglycan, typically extremophiles (lives in extreme environments), is a thermophile (heat-lover), is a acidophile (acid-lover), and is a halophile (salt-lover) Bacteria: Possess a rigid cell wall made of peptidoglycan, and is a mesophile (moderate-lover) Same: Both a prokaryote, both unicellular, both are asexual reproduction, and both have a cell wall 11. What the three common shapes of Bacteria and Archaea are with the key characteristics for each and examples of each. Cocci (Spherical): - Has different arrangements which are diplococci (chains of cocci), streptococci (chains of cocci), staphylococci (clusters resembling bunches of grapes), tetrads (groups of four cocci arranged in a square), and sarcina (cubical packets of eight or more cocci) - Reproduce through binary fission - Examples are streptococcus (causes strep throat), staphylococcus (can cause skin infections), and neisseria (causes gonorrhea) Bacilli (Rod): - Has different arrangements which are single (individual rod shaped cells), diplobacilli (pairs of bacilli), - Reproduce by binary fission - Examples are bacillus (causes anthrax), escherichia coli (some strains cause food poisoning), and clostridium (causes tetanus) Spirilla (Spiral): - The structure has a rigid shape and flagella - Reproduce through binary fission - Found in aquatic environments - Examples are spirillum (causes rat bite fever), campylobacter (causes food poisoning), and helicobacter (associated with stomach ulcers) 12. How we classify bacteria. - Gram Staining - Oxygen Requirements - Cell Wall Composition - Metabolism - Reproduction - Genetic Analysis - Disease Causing Ability - Spore Formation 13. What Aggregations are and what its purpose is. - Cells that are grouped together - Some cells will aggregate into colonies (groups) to work together - Sometimes the cells in the groups will have different functions serving the group, however, they are not multicellular - The purpose of aggregation is to enhance survival by the cells working together and protecting each other 14. What methanogens are and what methanogenesis are. Also to which group (Archaea or Bacteria) it is unique. Methanogens: Are a type of microorganism that produce methane as a byproduct of their metabolism. They are anaerobic organisms, meaning they thrive in environments without oxygen. Methanogenesis: Is the biological process by which methanogens produce methane, typically by converting carbon dioxide and hydrogen into methane in environments such as swamps, marshes, and the digestive systems of animals like cows. Unique: It is unique to the Kingdom Archaea are Methanogens. They are strict anaerobes which produce methane as a waste product. 15. What cyanobacteria is. Cyanobacteria: Are photosynthetic bacteria that produce oxygen and are important for nitrogen fixation and the base of many aquatic food chains. 16. Compare and contrast Extremophile and Mesophile. Extremophile: Live in very hot or cold environments, is found in extreme places, they have special proteins and enzymes to survive extreme conditions, important in extreme environments and special chemical cycles, examples are heat-loving, cold-loving, and salt-loving Mesophile: Live in moderate temperatures, found in everyday environments, have proteins suited for regular temperatures, important in regular ecosystems and processes like digestion, examples are escherichia and lactobacillus Same: Both are microorganisms, both require specific environmental conditions for survival, both have specialized metabolic processes suited to their environments, both play important roles in ecosystems, and both can be found in various environments 17. What binary fission is. Binary Fission: Is a form of asexual reproduction in which a single organism divides into two identical daughter cells. 18. Harmful and beneficial bacteria with examples. Beneficial Bacteria: - Decomposers - Aid in digestion (E.g. E. Coli in the intestine) - Nitrogen fixation - Source of antibiotics and useful drugs (E.g insulin) - Used to make dairy products (E.g. Cheese, yogurt) and alcohol - Examples are lactobacillus, bifidobacterium, escherichia, streptomyces, and rhizobium Harmful Bacteria: - Cause disease (e.g. strep throat, pneumonia, skin infections) - Food spoilage - Food poisoning (e.g. salmonella) - Can be spread through direct contact, air, water, open wounds  - Examples are E. coli, salmonella, streptococcus pyogenes, mycobacterium tuberculosis, and clostridium botulinum 19. The different types of bacteria. Clostridium Botulinum: Is an anaerobic bacterium that can cause illness in humans. It forms endospores that are very resistant to heat and that germinate in anaerobic conditions. Streptococcus Pyogenes: Is a Gram-positive bacterium that causes strep throat infections. Streptococcus Mutans: Is a Gram-positive bacterium that causes tooth decay. 20. Be able to identify a virus, bacteria and archaea, and a protist by looking at a micrograph. Virus: Bacteria: Archaea: Protist: Eukaryotic Evolution and Diversity (2.3) 21. The name of the theory that explains how eukaryotic cells are evolved. Theory of Endosymbiosis 22. The key points of the endosymbiotic theory. - Eukaryotic cells evolved through a symbiotic relationship between different species of prokaryotic cells - An ancestral eukaryotic cell engulfed certain prokaryotic cells, but instead of digesting them, a symbiotic relationship was formed - The engulfed prokaryotes became the mitochondria and chloroplasts - The engulfed prokaryotes provided benefits, such as energy production while the host cell provided a stable environment and resources - Mitochondria and chloroplasts have their own DNA that is separate from the DNA in the cell’s nucleus - The DNA structure of mitochondria and chloroplasts are similar to certain types of bacteria. - Both mitochondria and chloroplasts have two membranes, which could result from the engulfing process - Mitochondria and chloroplasts replicate independently, similar to how bacteria divide - The theory is supported by molecular and structural evidence showing strong similarities between these organelles and certain prokaryotes 23. Advantages that multicellularity provides over unicellularity. - Different cells can perform different tasks - Multicellular organisms can grow bigger, which helps with defense, hunting, or access to resources - Multicellular organisms can survive longer because not all cells are affected by damage or disease at once - Different cells can work together more efficiently, performing complex functions like digestion, circulation, and reproduction - Multicellular organisms can adapt to changes in the environment better with specialized cells that handle specific conditions - Multicellularity allows for more complex behaviours, like movement, thinking, and coordination, that single cells can’t do 24. In regards to the three types of sexual life cycle, a. What is common to all three b. What differs between the three a. - All three cycles involve meiosis to create haploid gametes - All three cycles involve fertilization, where two gametes combine to form a diploid zygote - All three life cycles have both haploid and diploid stages b.  - Haploid Dominant: The organism is mainly haploid, with a short diploid stage during zygote. - Diploid Dominant: The organism is mainly diploid, with a short haploid stage - Alternation of Generations: Both the haploid and diploid stages are multicellular Protists (2.4) 25. The different types of features of protists. - Unicellular, colonial, or multicellular organisms - All types of nutrition - Found in fresh or saltwater - Often contain a discrete, membrane-bound nucleus - Also contain ribosomes, mitochondria, and lysosomes - Usually reproduce asexually by binary fission 26. The different features that make protists “animal-like”, “plant-like”, or “fungus-like”, and what they might look like. Animal-Like Protists: - Range in size from 2 μm to 5 cm - Are all heterotrophic - Holozoic - engulf their food - Saprozoic - absorb solid nutrients through membrane - Move around to obtain food - Many of them are also parasites - They might look like Protozoa, Amoeba, and Ciliates Plant-Like Protists: - Prefer most environments; can grow on tree trunks and rocks - Most are autotrophs, some are heterotrophs - Autotrophs contain chlorophyll that traps sunlight energy for photosynthesis - They might look like Algae, Diatoms, Dinoflagellates, and Euglenoids Fungi-Like Protists: - Also called slime moulds - Prefer cold, shardy, moist places  - Feed on organic matter - Complex life cycles where organisms change from unicellular to multicellular organisms - They might look like slime molds and water molds 27. What the three locomotive features of protists are. Pseudopodia: A temporary cytoplasmic extension that amoebas use for feeding and movements. Cilia: A short, hair-like projection that functions in cell movement and particle manipulation when coordinated with other cilia. Flagella: A long, hair-like projection extending from the cell membrane that propels the cell using a whip-like motion. 28. Why it difficult to make generalizations about organisms in the kingdom Protista. It's hard to make generalizations about the organisms in the kingdom Protista because they are so diverse, including organisms that are like animals, plants, and fungi. They can have different shapes, behaviors, and habitats, making it tough to categorize them all in one group. Algae (3.1) - Beginning of Plants Slides 29. The kingdom where the algae is placed and if they are unicellular or multicellular. Algae are placed in the Kingdom Protista. They can be both unicellular or multicellular. 30. What the three major types of multicellular algae are and which of the three represents the evolutionary “link” between algae and plants. The three major types of multicellular algae are green algae, brown algae, and red algae. Green algae are considered the evolutionary "link" between algae and plants because they share similar pigments and cellular structures with land plants. 31. Identified how the following adaptations allowed the move to life on land. a. Vascular tissue and true roots b. Embryos protected by seeds c. Flowers  a. Vascular tissue and true roots allowed plants to transport water and nutrients efficiently, which is crucial for surviving on land where water isn’t as abundant as in water. True roots also anchor plants in the soil, helping them stay stable and get the resources they need. b. Embryos protected by seeds allowed plants to survive harsh land conditions by providing a safe environment for the young plant to develop before being exposed to the outside world. Seeds also help plants disperse to new areas, making it easier to spread and grow on land. c. Flowers allowed plants to reproduce more effectively on land by attracting pollinators, which increased the chances of successful fertilization. This helped plants to produce offspring without needing water for sperm to swim to the egg. Plants (3.1 - 3.2) 32. What the earliest ancestor of land plants is. A type of green algae, specifically a group called charophytes. 33. If seaweed and kelp plants or algae protists. Seaweed and kelp are algae, specifically protists, not true plants. a. If green algae, red algae, and brown algae is seaweed or plants. Are types of seaweed, not true plants. 34. What a gamete cell is and if it is a diploid or haploid. Gamete Cell: Is a reproductive cell, such as a sperm or egg. It is a haploid. 35. The difference between diploid and haploid cells. A diploid cell has two sets of chromosomes, while a haploid cell has only one set of chromosomes, which is half the number found in diploid cells. 36. The difference between nonvascular and vascular plants. Nonvascular plants, such as mosses, lack specialized tissues for transporting water and nutrients, so they rely on diffusion. Vascular plants, like ferns and trees, have vascular tissues that efficiently move water, nutrients, and sugars throughout the plant. 37. The major differences between these three types of plants: bryophytes, seedless vascular plants, and seedless nonvascular plants. Bryophytes are nonvascular and rely on diffusion for water and nutrient transport. Seedless vascular plants (like ferns) have vascular tissues for transport but reproduce through spores, while seedless nonvascular plants lack vascular tissues and also reproduce by spores. a. Examples of plants under each category. i. Bryophytes ii. Tracheophytes iii. Gymnosperms iv. Angiosperms a. i. Bryophytes: Mosses, liverworts, and hornworts ii. Tracheophytes: Ferns, club mosses, horsetails iii. Gymnosperms: Pine trees, spruces, firs, and cycads iv. Angiosperms: Roses, sunflowers, oaktrees, and grasses 38. What the purpose of seeds is and the benefit. The purpose of seeds is to protect and nourish the developing embryo plant, allowing it to survive in various environmental conditions until it can grow. The benefit of seeds is that they enable plants to reproduce and disperse to new areas, increasing their chances of survival and growth. 39. How reproduction differs in gymnosperm vs. angiosperms. Gymnosperms reproduce by producing exposed seeds on cones, while angiosperms have seeds that are enclosed inside flowers and develop into fruits. Gymnosperms are usually pollinated by wind, while angiosperms often rely on animals or insects for pollination. a. How gymnosperms and angiosperms are similar. Gymnosperms and angiosperms are similar because both are seed-producing plants. They both go through a process of pollination and fertilization to create seeds for reproduction. 40. The function of flowers and fruit. Function of Flowers: - Attract pollinators - Facilitate fertilization Function of Fruit: - Protect developing seeds - Aid in seed dispersal 41. What a cotyledon is and how it is used to classify angiosperms. Cotyledon: A cotyledon is the first leaf or pair of leaves that appear in a seed during germination. Angiosperms are classified into two groups based on the number of cotyledons: monocots and dicots. 42. The type of weather/climate where gymnosperms and angiosperms grow. Gymnosperms typically grow in cooler climates, like conifer forests, and can survive in dry or cold environments. Angiosperms, on the other hand, grow in a wider range of climates, from tropical to temperate regions, and are more adaptable to different weather conditions. 43. The plant life cycle. 44. The diagram of flowers and plants. Flowers: Plants: a. The fern diagram with new key terms and steps. i. What an archegonium, antheridium, sporophyte, pinna, and sori is. Archegonium: Is the female reproductive structure in plants like ferns, where eggs are produced. Antheridium: Is the male reproductive structure in plants like ferns, where sperm are made. Sporophyte: Is the diploid stage in the plant life cycle that produces spores for reproduction. Pinna: Is a small leaf or leaflet in ferns, usually part of a larger frond. Sori: Are clusters of sporangia (spore-producing structures) found on the underside of fern leaves. 45. The diagram of plant reproduction. Fungi (3.3) 46. What hyphae, mycelium, fruiting body, gills/lamellae, and basidia are and the differences between them. Hyphae: Hyphae are the long, thread-like structures that form the basic building blocks of fungal growth. They are made of chains of cells and grow by elongation at the tips. They function in nutrient absorption, growth, and reproduction. Hyphae spread out in the substrate to gather nutrients for the fungus. Mycelium: Mycelium is the entire network of hyphae, often referred to as the "root" system of the fungus. It’s the vegetative part of the fungus and can be spread over a large area. It serves as the main growth structure of the fungus, absorbing nutrients and water from its environment. Mycelium can be found in the substrate where the fungus is growing. Fruiting Body: The fruiting body is the reproductive structure of the fungus, which produces and releases spores. In many fungi, this is the part of the fungus that is visible to the naked eye. The fruiting body is designed to produce and disperse spores, the reproductive units that will grow into new fungal organisms. Gills/Lamellae: Gills or lamellae are thin, blade-like structures found under the cap of many mushrooms that house the reproductive cells where spores are produced. Gills provide a large surface area for the production of spores. They are crucial for spore dispersal as they release the spores into the air. Basidia: Basidia are specialized microscopic cells found on the gills of fungi, particularly basidiomycetes. Basidia are the structures that produce spores. Each basidium typically produces four spores via meiosis. a. What the difference is between a fruiting body vs. mycelium. The mycelium is the vegetative, network-like structure of the fungus responsible for growth and nutrient absorption. The fruiting body is the reproductive structure that produces and releases spores, typically visible as mushrooms or other fungal formations. 47. How all fungi obtain their nutrients. Fungi obtain nutrients by absorbing organic matter through external digestion, using enzymes to break down substances. They can be saprophytic (decomposing dead matter), parasitic (feeding on living hosts), or mutualistic (forming symbiotic relationships with other organisms). 48. A brief description of the nutrition and examples: a. Parasitic Fungi b. Predatory Fungi c. Mutualistic Fungi d. Saprobial Fungi a. Parasitic Fungi: Parasitic fungi absorb nutrients from the living cells of a host organism. In most cases, the fungus lives inside the host organism. For example, Cordyceps invade an insect's body. b. Predatory Fungi: Predatory fungi are soil fungi whose mycelia have specialized structures for trapping prey. For example, the rings in the hyphae of Arthrobotrys trap tiny worms, called nematodes, that live in the soil. c. Mutualistic Fungi: Mutualistic fungi have partnerships with other organisms, often plants or protists. In most cases, the mycelia cover the roots of a plant. This mutualistic relationship is called mycorrhiza, which is also the example. d. Saprobial Fungi: A saprobe is an organism that feeds on dead organisms or organic wastes. Saprobial fungi are decomposers whose mycelia absorb nutrients from dead or decaying organic matter. They play an important role in recycling nutrients in ecosystems. An example of saprobial fungi is Agaricus bisporus, the common mushroom. This fungus decomposes organic matter, such as dead plant material, helping recycle nutrients in the soil. 49. What criteria is used to classify fungi into their five groups. The main factors used to classify fungi are: 1. Reproductive Structures: The way fungi produce spores, such as sexual or asexual reproduction, and the structures involved. 2. Spore Types: The types of spores produced, like conidia, basidiospores, or ascospores, which differ between groups. 3. Morphological Characteristics: The shape, size, and structure of the fungal body, such as hyphal structure and the presence of specialized structures like fruiting bodies. 4. Mode of Nutrition: Whether the fungus is saprophytic (decomposing organic matter), parasitic (feeding off living organisms), or mutualistic (forming symbiotic relationships). Examples in our everyday life: 1. Ascomycota (Sac Fungi): - Use: Yeasts used in baking and brewing. - Presence: Molds like Aspergillus and Penicillium found on food and in damp environments. 2. Basidiomycota (Club Fungi): - Use: Mushrooms used in cooking. - Presence: Common in gardens and forests, helping with nutrient cycling. 3. Zygomycota (Zygomycetes): - Use: Molds like Rhizopus used in food fermentation. - Presence: Found on decaying food and organic matter. 50. What Penicillin is. Penicillin: Is an antibiotic derived from the Penicillium mold that inhibits bacterial cell wall synthesis, effectively treating various bacterial infections. 51. What lichen is and how lichens are ecologically important. Lichen: An organism that results from a mutualistic relationship between a fungus and a photosynthetic plant or alga. Lichens are ecologically important as pioneer species that aid in soil formation, nutrient cycling, habitat creation, and air quality monitoring, while also contributing to carbon sequestration and nitrogen fixation. 52. What the uses of fungi are and how we as humans have been able to make use of fungi in our daily lives with examples. Fungi are used in various ways in our daily lives, such as yeast in baking and brewing, and mushrooms as a food source. In medicine, fungi have provided crucial antibiotics like penicillin, as well as other therapeutic compounds. Additionally, fungi play a role in biotechnology, producing enzymes for industrial processes, and in environmental cleanup through bioremediation of pollutants. Simple Animals & Invertebrates (3.4) 53. What the key characteristics of all animals are. - Heterotrophic, multicellular, eukaryotes - Lack cell walls - Specialized nervous & muscle tissue - Primarily sexual reproduction 54. What an invertebrate is. Invertebrate: Animals without backbones. 55. What segmentation is and what’s its advantage. Segmentation: Division of the body into repetitive sections/segments. Advantages: A damaged segment can still have other segments continue to function properly Segments can move independently so there is mobility = allows complex movements 56. What body symmetry is and what body plans are. Body Symmetry: Refers to the way an organism’s body is arranged, where its structure can be divided into equal or similar parts, such as bilateral, radial, or asymmetry. Body Plans: Describe the overall organization and structural layout of an organism’s body, including features like symmetry, segmentation, and the arrangement of organs. 57. What a gastrovascular cavity is. Gastrovascular Cavity: Is a central digestive space in certain animals, such as cnidarians, where digestion and nutrient distribution occur through a single opening that serves as both mouth and anus. 58. What the different ways to classify animals are. Levels of Organization: - All animals have cells - Mostly all animals organize cells - tissues - organs - organ systems ➔ Exception of sponges that don’t organize cells into tissues - Structure and complexity of organ system differ between animals Number of Body Layers: - All animals except sponges and animals in Phylum Cnidaria (corals, hydras, jellyfish, and sea anemones) have 3 layers of cell: ➔ Ectoderm (outer layer) ➔ Mesoderm (middle layer) ➔ Endoderm (inner layer) - These layers help sort cells into an arrangement that produces specialized tissues and organs in the adult animals Symmetry and Body Plans: - Used to classify animals - Features: ➔ Body symmetry: asymmetrical, bilateral or radial ➔ Degree of cell organization: function independently or form tissues and organs ➔ Presence of a coelom (internal body cavity) Body Cavity: - Presence of a coelom: ➔ A fluid-filled body cavity that provides space for the development and suspension or organs and organ systems - Coelomates (with coelom): worms, molluscs, insects, and vertebrates - Acoelomates (with coelom): corals, jellyfish, and flatworms Segmentation: - Segmentation: Division of the body into repetitive sections/segments. - Advantages:  ➔ A damaged segment can still have other segments continue to function properly ➔ Segments can move independently so there is mobility = allows complex movements Movement: - Development and evolution of tissues (i.e,, nerve and muscle tissue) allowed for complex and fast movement - Some animals can be sessile/stationary ➔ Ex: sponges/ sea anemones ➔ Sessile animals have a body form that can move during juvenile stages of development Reproduction: - Animals reproduce through sexual (involving gametes) or asexual methods (like budding or fission), with some animals having both reproductive strategies. 59. What ectoderm, mesoderm, and endoderm means. What it describes. If it describes the levels of organization, body layers, body cavity, segmentation, and symmetry. Ectoderm: Is the outermost layer of cells in the early embryo that develops into the skin, nervous system, and other structures. Mesoderm: Is the middle layer of cells in the early embryo that gives rise to muscles, bones, the circulatory system, and other internal structures. Endoderm: Is the innermost layer of cells in the early embryo that develops into the lining of the digestive and respiratory systems, as well as other internal organs. Describe: Together, these three germ layers describe the early stages of development that lead to the formation of all the body's structures. It describes body layers that develop into specific tissues and organs, rather than directly addressing body cavities, segmentation, or symmetry. 60. Two major invertebrate groups with the defining characteristics and an example. Arthropods: - Exoskeleton made of chitin - Segmented bodies - Jointed appendages (legs, antennae) - Bilateral symmetry - Open circulatory system - Examples: Spider, Ant, Crab Mollusks: - Soft, unsegmented bodies (often with a hard shell) - Mantle (tissue that secretes the shell in many species) - Muscular foot for movement - Radula (in most species) for feeding - Bilateral symmetry - Examples: Snail, Clam, Octopus 61. What the difference between exoskeleton and endoskeleton is and what the advantages of the exoskeleton for invertebrates are. Difference: An exoskeleton is an external hard structure that supports and protects an organism, while an endoskeleton is an internal framework that provides support and shape to the body. Advantages: The advantages of an exoskeleton for invertebrates include providing protection from physical damage and predators, offering structural support without requiring internal bones, and enabling mobility through jointed appendages. Vertebrates (3.4d): 62. What the difference between invertebrate vs. vertebrate animals are. The main difference between invertebrate and vertebrate animals is that invertebrates lack a backbone or spinal column, while vertebrates have a well-developed internal skeleton with a backbone made of vertebrae. 63. What a notochord is. Notochord: Skeletal rod of connective tissue that runs lengthwise along dorsal surface. 64. “All vertebrates are chordates, but not all chordates are vertebrates.” Explained. The statement "All vertebrates are chordates, but not all chordates are vertebrates" means that all vertebrates are part of the larger group of chordates, which share certain features like a notochord, dorsal nerve cord, and pharyngeal slits. However, not all chordates develop a backbone; some, like tunicates and lancelets, only have the chordate features in their early stages and remain without a backbone as adults. Thus, vertebrates are a specific subgroup within the broader chordate group. 65. The characteristic features of: a. Fish d. Birds b. Amphibians e. Mammals: monotremes, marsupials, placentals c. Reptiles a. Fish: - Most numerous of all vertebrates - Divided into 3 groups: 1. Jawless fish 2. Cartilaginous fish 3. Bony fish 1. Jawless Fish: - Smooth, eel-like bodies - Skeleton made from cartilage - No paired fins - E.g. silver lamprey 2. Cartilaginous Fish: - Rough, stream-lined bodies - Cartilage skeleton - Paired fins - Biting jaws with triangular shaped teeth - Sensory cells along body, lateral line 3. Bony Fish: - Body covered with flexible scales - Skeleton made of bone - Have a swim bladder that helps the float - Fertilization occurs externally - Female lays eggs - Male deposits sperms over eggs b. Amphibians: - Divided into 3 groups: 1. Legless amphibians; e.g. wormlike caecilians 2. Tailless amphibians; e.g. frogs, toads 3. Tailed amphibians: e.g. salamanders - Fertilization occurs externally - Have 2 life stages ➔ Tadpole stage lives in water ➔ Adult stage lives on land - 3 chambered heart, not efficient - Gas exchange occurs through lungs and through skin c. Reptiles: - First fully terrestrial vertebrates to evolve - Divided into 3 groups: 1. Anapsid; e.g. turtles, tortoises 2. Lepidosauria; e.g. lizards, snakes 3. Archosauria (Diapsid); e.g. crocodiles, alligators, dinosaurs! - Dry, waterproof skin to prevent water loss - 3 chambered heart, not efficient - Gas exchange increased by internal folds in lungs - Internal fertilization - Lay amniotic eggs that provide self-contained environment for growing embryo - Lightweight skeleton and muscles allow movement across and (dragging) d. Birds: - Divided into 5 subgroups based on type of feet and beaks - Elongated, wing-like hands - Have feathers; provide insulation and protection for skin - Lay eggs - 4 chambered heart allows for efficient transport of gases - Lungs have air sacs that allow for efficient gas exchange - Lack bladder, help reduces weight ★ Reptiles and birds are closely related e. Mammals: - Bony skeleton to protect vital organs - Warm-blooded - Four-appendages, animals with teeth  - Skin covered with hair (also sweat glands) to regulate body temperature - Breathe air using lungs and a diaphragm - 4 chambered heart - Complex brain allows to learn new behaviours - Reproduce sexually, and usually gives birth to live young (viviparous) - Mammary glands provide milk for young - Divided into 3 groups: 1. Monotremes 2. Marsupials 3. Placental Mammals 1. Monotremes: - Oviparous - Reproduce by laying eggs - E.g. platypus 2. Marsupials: - Born not fully mature - Continue to develop in pouch on ventral side of mother - E.g. kangaroo, koala 3. Placental Mammals: - Embryo develops in uterus of female - Umbilical cord connects placenta to developing embryo - Some young are very dependent on care from mother, others not so much - E.g. human, dolphin, horse 66. If reptiles and birds are related. How do we know. What evidence supports this. Yes, reptiles and birds are related, as both belong to the group called archosaurs, sharing a common ancestor. Evidence supporting this includes similarities in skeletal structure, such as the arrangement of bones in limbs and pelvis, as well as the presence of feathers in birds, which evolved from reptilian scales. Additionally, both lay eggs with protective shells, and genetic studies show birds are closely related to certain dinosaurs, a type of reptile. 67. What oviparous vs. viviparous is. How we would classify a platypus. If it is a marsupial or mammal or monotremes. Difference: Oviparous animals lay eggs that develop and hatch outside the mother's body, while viviparous animals give birth to live young that develop inside the mother's body. Classified: A platypus is classified as a monotreme, a group of egg-laying mammals. Unlike most mammals that are viviparous, monotremes like the platypus lay eggs but still produce milk to nourish their young after hatching.