Biology: Features & Classification of Organisms

Features of Living Organisms

• Living organisms share features summarized as Mrs. Nerg or Mrs. Gren: movement, respiration, sensitivity, nutrition, excretion, reproduction, and growth (increase in size).
• Non-living things don't exhibit these characteristics, such as viruses.

Classification Systems

• Billions of organisms exist, so naming them is complex, thus classification systems are necessary.
• Classification groups organisms based on shared features.
• The binomial naming system names organisms with species and genus (e.g., Mycobacterium tuberculosis).
• Species: a group of organisms able to reproduce to produce fertile offspring.
• A horse and donkey can reproduce, but their offspring (a mule) is sterile/infertile, therefore the parents are not the same species.
• Traditional classification used evolutionary similarities, morphology, and anatomy (bone structure).
• Modern classification uses DNA base sequences and resulting amino acids in proteins for better accuracy.
• More similar DNA sequences indicate a closer relationship.

Dichotomous Keys

• Dichotomous keys are visual tools using past exam questions to show how to approach answering questions.
• Approach from the animal's perspective, not the table's.

Taxonomic Classification

• The five kingdoms are plants, animals, protists, bacteria, and fungi.
• Vertebrates are animals with a backbone.
• Distinguishing features of vertebrates:
  • Mammals: Furry skin, mammary glands to produce milk.
  • Birds: Feathers, scales on legs.
  • Reptiles: Dry, scaly skin (e.g., lizards, snakes).
  • Fish: Scales, fins, gills, operculum (gill cover), lateral line with sense organs.
  • Amphibians: Moist skin (e.g., frogs).
• Invertebrates, like arthropods, lack a backbone but have exoskeletons.
• Arthropod groups:
  • Myriapods: Antennae, many body segments, hard exoskeleton (e.g., millipedes).
  • Insects: Antennae, three body parts (head, thorax, abdomen), compound eyes, two pairs of wings, three pairs of legs (six legs).
  • Arachnids: Simple eyes, combined head and thorax, eight legs (four pairs), powerful jaws, spinnerets for silk (e.g., spiders).
  • Crustaceans: Hard outer casing (carapace), claws with serrated edges, eyes, jointed limbs, gills under shell (e.g., lobsters, crabs).
• Flowering plants (angiosperms):
  • Produce flowers, fruits, and seeds.
  • Have extensive root systems for water and minerals.
  • Have xylem and phloem transport systems.
  • Stomata allows CO2 in and O2/H2O out.
  • Can be monocots or dicots (number of initial leaves).
• Ferns:
  • Have leaves called fronds.
  • Fronds contain sporangia that release spores in reproduction.
  • Underground rhizomes with nodules send out roots/shoots.
  • Simple root systems.
• Viruses:
  • Protein coat surrounds genetic material (DNA or RNA).

Cell Types

• Bacterial cell:
  • Has a cell wall, slime capsule (sometimes), flagellum, cytoplasm, and cell membrane.
  • Lacks a distinct nucleus; has a circular chromosome (nucleoid).
  • Has small rings of DNA (plasmids; important in genetic engineering).
  • Can be pathogenic (disease-causing) or non-pathogenic (e.g., Lactobacillus bulgaricus in yogurt).
  • Unicellular (one cell only).
• Viruses:
  • Very small, simple; protein coat around DNA/RNA.
  • Non-living: do not excrete, respire, or grow.
  • Always pathogenic (e.g., flu, cold, HIV).
• Protists:
  • The “Dustbin Kingdom” for variable organisms.
  • Some have animal cell properties, others plant cell properties.
  • Algae and Corella: plant-like with chloroplasts.
  • Amoeba: animal-like, no chloroplasts or cell wall.
  • Obtain nutrients and oxygen by diffusion.
  • Plasmodium is pathogenic (causes malaria; lives in female mosquitos).
  • Can be unicellular or multicellular.
• Fungi:
  • Similar organelles as plant cells (but no chloroplasts).
  • Cell wall made of chitin.
  • Cell membrane, cytoplasm, vacuole.
  • Muccor and mushrooms are examples.
  • Saprotrophic nutrition: secrete enzymes, break down, and absorb dead matter for food.
  • Yeast is a useful fungi: glucose to ethanol (beer) and CO2 (bread) in anaerobic respiration.
• Plant and Animal Cells:
  • Shared organelles: cell membranes, cytoplasm, nuclei, ribosomes, mitochondria.
  • Plant cells have cell walls, vacuoles, and chloroplasts.

Organelles

• Nucleus: Controls cell activities.
• Cytoplasm: Where chemical reactions take place.
• Cell membrane: Controls what enters and leaves the cell.
• Ribosomes: Where protein synthesis takes place.
• Cell wall: Made of CELLULOSE, protects and supports the cell.
• Vacuole: Filled with CELL SAP, maintains cell structure.
• Chloroplast: Contains chlorophyll, a green pigment.

Eukaryotes & Prokaryotes

• Eukaryotes: animal cells; have membrane-bound organelles (nuclei, mitochondria etc.)
• Prokaryotes: no membrane-bound organelles; have DNA strands (no nuclei)

Specialized Cells

• Red blood cell:
  • Transports O2; contains hemoglobin (binds O2, forms oxyhemoglobin).
  • Biconcave disc shape (increased surface area); no nucleus (more hemoglobin).
  • Flexible (passes through narrow capillaries).
• Muscle cell:
  • Contracts and relaxes for movement.
  • Long; contains protein fibers (shorten when energy available for contraction).
• Trachea cells:
  • Ciliated cell: contains cilla, small hairs waft mucus laden with bacteria out of the trachea in to the mouth where it can be swallowed.
• Motor nerve cell:
  • Transports signals; conducts electrical impulses.
  • Long axon (electrical impulse carrier); fatty sheath (myelin sheath increases speed).
  • Branched endings (reach other cells).
  • Transports signals so can conduct electrical pulses.
• Sperm cell:
  • Reproduction; fuses with ovum (fertilization) to produce a zygote.
  • Flagellum/tail (swimming); many mitochondria (energy); acrosome with digestive enzymes (penetrate egg).
• Ovum:
  • Reproduction; haploid number of chromosomes.
  • Outer layer (jelly coat) changes after sperm penetration.
• Root hair cell:
  • Absorbs water and mineral ions.
  • Root hair (increased surface area); water absorption by osmosis; mineral ions by active transport.
• Xylem:
  • Transports water from roots to leaves.
  • Made of dead cells (continuous column); lignin strengthens walls.
• Phloem:
  • Transports sugars to plant
  • Transports sugars both up and down the plant

Organization

• Cell: A group of organelles working together to perform the same function.
• Tissue: A group of cells working together to perform the same function.
• Organ: A group of tissues working together to perform the same function.
• Organ System: A group of organs working together to perform the same function.
• Organism: A group of organ systems working together to perform the same function.

Converting Units

• Pico meter, nanometer, micrometer, millimeter, meter, kilometers, Mega meter.
• Multiplying by 1000 converts between the various steps.

Transport

• Diffusion is the net movement of particles from an area of high concentration to an area of low concentration and is a passive process with no energy required.
• Osmosis is the net movement of water from an area of high water potential to an area of low water potential across a partially permeable membrane.
• Active transport requires movement form ana area or low concentration to an area of high concentration and therefore requires energy.
• Amoeba, a single-celled organism gets nutrients via diffusion because it has an area large surface area to volume ratio.

Biological Molecules

• Organic compound: containing carbon.
• Organic elements include carbohydrate, hydrates, proteins, phosphorus, nitrogen and sulphur.
• Carbohydrates are broken down into 2 groups: monosaccharides and polysaccharides. Polysaccharides contain many sugars; key examples include cellulose, starch, and glycogen.
• Proteins are chains of amino acids whose order is determined by genes; this sequence determines protein shape and function.
• DNA looks like a ladder known as a double helix because it winds itself up. It creates the sugar phosphate backbone made of deoxy ribos which contains phosphate and sugar. The bases adenine, thymine, guanine, and cytosine form the rungs.
• Nucleotide : deoxy ribos sugar, a phosphate, A base (Adine, thyine, cytosine, or ganine).
• Complimentary base pairing: Guanine pairs with cytosine, and adenine and thyine always pair up.
• Enzymes are biological catalysts which speeds up the rate of a chemical reaction. The sustrate molecule binds to biologically active part of the enzyme called a active site to form enzyme substrate complex which the splits up to form the useful product.
• At low temperature enzymes have low kinetic energy as does the substrate so the molecules are note coming into contact often and after the reaction slows down because they can't find. as temperature increases activity increases molecules come together and at 37* enyme activity is its optium.
• Active at phes because enzymes have different optium and
• Denatured: When Active site has been changed

Photo synthesis

• Photo synthesis is carried out in the chloroplast of plant cells which contain chloral filled which absorbs sunlight and this is the method in which green plants make their own food
• Symbol equation: 6CO=2 6H2O C6H12O6 6O2+ limiting factors of the rate of photosynthesis can be Co2 Light intenseitty and Temperature

Structure of A leaf

• Large surface area absorbs more light
• Leaves are thin so gasses don't have to diffuse too far
• Waxy cutical- prevents transpiration
• Upper epidermis - transparent and it allows light leave
• Palisade mesophi- cell is what generic plant cells look like
• Spongy - presence of air spaces
• Upper idamis-
• Guard cells/ stomata allows carbon dioxide and oxygen into the leaf

Balance Diet

• Provides all the nutrients in the correct portions.
• Carbohydrates (bread, rice, pasta) are an important source of energy.
• Proteins (meat) are good for growth and repair muscles; lack of protein can lead to the Qashqua disease.
• Fats (dairy) is a source of energy that keeps you warm.
• Vitamin C fixes you to and from orange and lemons or repair tissues; lack of it leads to scurvy.
• Vitamin D is important for strong buns; you can get it from the sun and also from fish oil; lack of it leads to rickets.
• Iron blood and is a Really important components to hemoglobin
• Calcium the metal which is importance to 3 bones such as milk and lack of to rickets fiber
• Fiber helps food to move through the digestive system.
• A deficiency in energy and protein is known as marasmus; this is when you see muscle wasting on limbs.

Digestion

• Digestion involves the breaking down of large and insoluble molecules so the food can be absorbed through the walls of the small intestines. -Amala is is made in the salivary glands in your small intestine and your pancreas to carryalized the break down starting to glucose Enzymes and those name in AASE Protest is a down and they break down proteins into Amino assets. This is found in the small intestines lipase breaks down lipids and Fats the broken down from is fatty acids and glycerol Hydrochloride assets breaks down food and and destroyed pathogens
• A chemical reaction relates to emzy entirely because it's totally altering of molecules where mechanical digestion this has always it was a breaking the food of smaller pieces In sizers job is to slit or slice and crush or chew food

Transports In Plants

• Floam transports Glucose
• Xilemm transports water The outer layer of tissue transports glucose inner part transport water
• Mineral ions enter by effective transportation from soil again since is few are mineral ions in the soil compared to what inside so the soil is absorbed by using active transports

Water is absorbed by use root hairs by osmosis from air is a high water potential into the road hairell

• transpiration stream: Leaves Stomata by transportation as the Stromatals open the first droplet Leaves because the water molecules it's all the tax of each other dude to the presence of hydrogen bonding. This forms. A continuous column

Heart

• Four chambers
  • Left Atrium
  • Right Atrium
  • Left ventricle
  • Right Ventricle
• The walls of the ventricle is a thicker of the Atria of a higher rate because much higher pressure they have to deliver

Arteries, Veins, and Capillaries

• Arteries narrow, meaning that blood is going to be first in a high pressure cause it out the heart. Due to the high pressure, they're made for very thick withstand this pressure be night and state then what muscle and elastic
• Fibery walls looking at veins now in vain, blood has a much by that the volume the walls therefore need to be much thin so they have been muscle in the Austin Fiber walls
• They contain Valves to prevent back flows of floods
• 1 sales thick this in able the short to fusion distant

Brain Cells and Platelets

• Platelets are small fragments that seal to blood where scabs are Plasma- is the liquid that carers cell around
• Glycogen-Red blood cells for protein Bicanocave Shape maximize are for oxygen also to have nuclei which makes move for oxygen have the Pigment
• Hemoglobin which make iron
• lymphate protects from pathogens. Each antibody Has the specific binding site. If you specific my cues and My cues that bond to antibodies are known as antigens, the vaccine will give the immune system to increase the protection from the particular virus

Breathing and Aerobic Respiration

• The breathing system that we will be to is lungs. Starts with mouth
• Travels to trachia branches to bonchy further ending where lungs where Alvioli covered in capillary tubes Alviola is thin which gives short distance moist also has a larger surface area
• Inhale- Externa muscle constract
• Exhale- Internal Muscle Contacts Is a product of metabolism from the body

The Nervous System

• Stimulus: Changes in the movement (Detected by senes organis)
• Sensory system: Eye, ears, sking, tounge and nose
• Hormornes are chemical which travels in blood
• Comparison in Nerverous system: Faster more lookilized longer shorter responses / electrical impulse
• Receptors: Picked up by signals into sensory nerve into spinal cod and Brain

Lens

• Accommodation adjust for distance

Adrenaline

• Released when under stress
  • Diliates Pupils
  • Heartbeat increased
  • Blood diverts from dignesion

Balanced

• After eatin- Blood sugar level increases hormone called insuling from panacrase causes it changes the soluble sugars into glycogen
• After excercise hormone called Glucogon turn glycogen into soluable sugars

Chromosomes

• Mitosis, Myosis
• Mitosis: Used clone and for asexual
• Myosis: Is to make gamates are both styles of a cell
• Myosis is a generally and equal type
• A cell can be called are so and are used to create it

Terminology

-The Geno- is what in organism contain

• Phenotype: Is physical apperance
• Genotype: Is a group of AL
• Hetero: Is to different Al
• Homo: Is same
• Chromozomes have two six in women and men and to do and then why chromosomes contains a lot of genes associate with that of sex but as far there and then code to charcateristics that that lead is sex
• CodoMins is IS one of both AL
• Blood groups
• Is there that was the Smith family has that you may notice that has that the genotype is
• Then for I'm the wife that you will either be and a

Eco systems and population

• Environment: Factors that are the non-bio component such of soils and water
• Habitat: What speific organ Live
• Population: Which or find
• Community: Population was special ecosystem of the
• Pro- a plant what to produce to own food
• Consumer: animals that eat other animals and plants
• The composer who decades for to recycle
• Parasite: lives other harms by doing it
• Predator and animal that keill for energy
• Bio Diversity:
• Biotic fact: factors that are lives
• Abiotion factors : Non Living

Food Chains and Webs

Food changes food from one place to another. Insects eat and insects create ennergy from eachother

• Very Little energies past where food and is digested.
• Vegetable are better because have only level of transfer and saves That it is good a
• the plant in the food chain make plant and energy

Cycles

Carbon cylcing: carbon dioxide In the Absorbing

Pop growth

Deforestation

Pollution

Sustainability