Cards Flashcards
Adaption
Physical trait that leads to organism’s increase in survival and reproduction
Fitness
An organism’s ability to reproduce
Theory of Evolution
Charles Darwin’s’ Theory: One way living things evolve
EVERY SPECIES OVERPOPULATES
Overpopulations- more babies than can handle
VARIATION
Lots of variation because we have so many babies
SELECTION
Some individuals are going to survive longer and produce more than others do.
ADAPTATION
Traits become more common in a population
Natural Selection
“Nature selects” animals that are most likely to survive and reproduce
Increase of offspring with that adaptation
Examples of Natural Selection
Peppered Moths and Dandelions (for more info see page 1 on bio test notes)
Artificial Selection
Able to choose traits
Breeding by humans
Effect of Selection on Phenotype and Genotype
If the variation in the population is due to environmental influences alone, any advantage won’t be passed on to the next generation. So natural selection acts on phenotype, but it is the connection to genotype that makes it the mechanism of evolution.
Phenotypes are a combination of genes and environmental influences
Artificial Breeding
Man bread fox and dog together
Chose the tamest of a fox and a dog and bred them together to create a hybrid
Theory
A well supported explanation that unifies a broad range of observations
Theories Explain
Based on loads of experiment
Evidence of Evolution
We all start off the same Evolution explains biodiversity DNA, genetic code, protein Fossil Record, Anatomy: Homologous structures Analogous Structures Vestigial Structures, Embryology, Biochemistry
Fossils
Impression of an ancient organism preserved in rock
The higher up in the rock the younger
The deeper in the rock the older
How do fossils provide evidence for evolution?
Fossils show fewer and simpler species as you go back
Transitional Species Exist
E.g. Horse descendants increase in size and change from toes to hoof
Extinction and formation of new species
Biochemistry
Species that have a common ancestor have similar sequences of amino acids in their proteins or DNA sequences
The more similarities, the closer related the organisms are thought to be
E.g. Human and gorilla hemoglobin differ by one amino acid
Gorillas have 48 chromosomes
Humans have 46 chromosomes
Homologous Structures
Similar features in a common ancestor, but now have different functions and/or external structures
E.g. front limbs of vertebrates
Don’t look similar, but they have the same bone pieces
Analogous Structures
Features that serve identical functions and look somewhat alike but do not share a common ancestor
Mammals with wings have wings, but they aren’t all from the same ancestor
Vestigial Structures
Features that seems no useful function and are usually reduced in size
Structure was useful in an ancestor, but not useful to the current organism
E.g. humans and tail bones
Embryology
Early stages of vertebrate development are similar in different species
Different Evolutionary Pressures
Select different traits Different places Adaptations Depends on environments Sun shines most directly at equator Strong UV rays Can damage or cause cancer Higher and lower Latitudes Higher - less direct sunshine Paler skin Adaptation -Absorb UV rays well Makes vitamin D Light shines most directly at the equator Darker skin is more common in lower latitudes Lactose tolerance Lactose intolerance used to be almost universal Ability to drink milk provided an evolutionary advantage Recent evolution
Alleles can be maintained in a population if they are lethal
Traits do not appear until the individual reproduces E.g. Huntington Disease Don’t develop disease until older Already had children by time they learn of their disease E.g. Cancer Has to be recessive Can “hide” in heterozygous individuals E.g. sickle cell anemia Through natural selection Advantage at equator Heterozygous: gives little advantage against malaria Malaria cannot kill sickle shaped cells
Species
Members of a population that can mate and produce viable offspring
Speciation
wo populations of same species are separated and can’t interbreed
Species are isolated from one another
Species evolve as time passes
Species change so much they can no longer breed
Species are distinct species
When one species branches into two distinct species
Separation: through isolation (causes speciation)
Geographic Isolation
E.g. Kaibab squirrel and Abert’s squirrel
Got seperated and they no longer interbreed
Behaviour Isolation
Occurs when population are capable of interbreeding but have different behaviors that prevent this
E.g. Different Courtship Rituals
Different courtship dances, displays, and/or songs
Patterns of Evolution (causes of evolution)
Natural Selection, Migration, Mutation, Genetic Drift
Migration
Causes an animal to move from one place to another
Mutation
Errors in DNA
Lead to different variations
The stuff that evolution works on
Genetic Drift
NOT natural selection
“Random” Change in surviving and reproducing
Things just survive, but not because they’re more fit
Not because they have a better chance of survival
E.g. Stepping on Bugs
Step on mainly Green Bugs instead of Brown Bugs. Not intentional.
Most common in small populations
Genes drift by random chance
E.g. Elephant Seal
In the 1800s were hunted down
Had a small population
Set up protective law to not make them go extinct
Only current animal’s’ genes passed on to next generations
Trends in Evolution
Coevolution, Convergent, Extinction, Gradualism, Punctuated Evolution, Adaptive Radiation
Coevolution
A change of two or more organisms in close association with each other
E.g. insect pollinators coevolved with plants they pollinate
Hummingbirds and tube shaped flower
Convergent
Organisms appear similar but are not closely related
Happens when the environment selects similar traits
E.g. Sharks and Dolphins
E.g. Birds and Butterflies
Extinction
99.9% of all species are extinct
5 Cataclysmic Events
Most population perished in one of the 5
Possibly in 6th mass extinction right now
Gradualism
Gradual change over time
Slow evolution
Punctuated Evolution
Rapid evolution
Caused by major environmental changes
After disasters
Adaptive Radiation
A species evolves into a wide variety of highly specialized species
E.g. Finches
Early Earth
No life Bombardment by meteors HOT temperatures Not blue atmosphere CO2 NH3 (ammonia) CH4 (methane) H2O (g) Only a little of O2
Formation of Life
Happened in the water 1) Miller - Urey Experiment Mixed Chemicals: chemicals that were around during early earth, heat, and light (lightning) Made amino acids and nucleic acids Earth chemicals + lightning spark + warm early Earth (heat) --> simple organic compounds 2) Phospholipid bilayers spontaneously form Membrane spheres trapped chemicals First Fossils 3) ~3.6 BYA first life fossils Prokaryotes 4) ~3.4 BYA fossils: stromatolites Cyanobacteria
Basic Chemicals of Life
Gases given an electric shock formed building blocks of life
Amino acids, Fatty acids, Hydrocarbons
Places Organic Compounds Are From
Hydrothermal vents
Aboard meteorites
The First Organic Compounds
Fatty acids (lipids) for membrane Enzymes (to do all the work/catalyze reactions for cell) Genetic material (to transmit the information from parent to offspring) Possibly started as RNA
Geological Time Scale
Cenozoic: present-65 million years ago
Mesozoic: age of the dinosaurs (65 million years ago-245 million years ago)
Paleozoic: Started 544 million years ago
Precambrian time: 540 million years ago-the beginning of the earth
Dating Fossil Evidence
Relative dating
Comparing where fossils are found in Earth’s (rock) layers
Absolute Dating
Use radioactivity in elements to compare ages
Evolution of Life
First cells were anaerobic prokaryotes Anaerobic: live without oxygen Around for a long time Aerobic: live with oxygen Among the first life forms Cyanobacteria Unicellular Photosynthetic release oxygen into atmosphere
Precambrian Time
Almost 90% of Earth’s History 1st 4 billion years of Earth’s history 1.5 BYA: unicellular eukaryotes 2.5 BYA: multicellular eukaryotes 4 billion years of evolution
Importance of Oxygen (The Great Oxygenation)
Make some of the anaerobic prokaryotes go extinct
Oxygen is an electron hog
Made it possible for aerobic respiration to evolve
O2 forms O3 (ozone), which blocks UV rays and makes possible life on land
Water Blocks UV rays too
Oxygen allows for bigger life
Multicellular Life
2.5 BYA cyanobacteria add O2 to Earth’s atmosphere
530 MYA fish evolve in the oceans
430 MYA plants and fungi move onto land
420 MYA arthropods are first animals to move onto land
370 MYA amphibians are vertebrates to live on land
340 MYA reptiles evolved from amphibians
250 MYA dinosaurs evolve and come to dominate Earth
200 MYA first mammals evolve
65 MYA last mass extinction
0.5 MYA first Homo sapiens
Paleozoic Era
544-245 MYA Invertebrates already present 1st appearance of: Vertebrates Fish Amphibians Reptiles Insects Land animals (including reptiles) Plants
Mesozoic Era
245-65 MYA Age of dinosaurs 1st appearance of: Flowering plants Birds Mammals little ones
Cenozoic Era
65 MYA - Present Time Age of mammals Only because dinosaurs went extinct Life always fills open niches Grasses Appeared 1st Hominids The family humans are in 1st humans
Protist (“junk drawer”)
Kingdom First eukaryotes on Earth Simpler eukaryotes Lack tissue ~1.5 BYA Reproduce Sexually Asexually Have organelles Mostly Unicellular Vary in: Size Type Method of acquiring energy Classified as: Protozoa Algae Fungus-like
Protistan Categories
Protozoa, Molds (fungus-like), Algae (plant-like)
Protozoa
“First Animals”
Four Major Groups:
Ciliates, Amoebas, Flagellates, Sporozoans (don’t move)
All unicellular
Molds
Heterotrophs
Cannot produce their own food
Types:
Slime molds and Water molds
Algae
Range from microscopic to huge seaweeds Autotrophic (make their own food) Mostly aquatic Major groups: Algae and Phytoplankton
Protozoa (Ciliates)
Phylum Ciliophora Unicellular Heterotrophs Move by beating thousands of their short, hair-like projections called cilia Moving hair back and forth to propel themselves Habitats: Marine and Freshwater E.g. Paramecium and Stentor
Protozoa (Amoebas)
Phylum Rhizopoda Unicellular Heterotrophs Habitats: Water and Soil Use pseudopodia for engulfing food and moving place to place (Pseudopodia - foot-like extension of cytoplasm) [Used for movement or feeding] (Oozes to move)
Protozoa (Flagellates)
Belong to several different phyla Move using one or more long, whiplike flagella flagella-tail E.g. Dinoflagellates Euglena
Protozoa (Sporozoans)
Also called Apicomplexa Animal Parasites Live inside another organism Complex life cycle Involved in multiple hosts Carried in blood of host One type can cause malaria Plasmodium Goes with the flow
Algae (Phytoplankton)
Includes:
Diatoms and some dinoflagellates
Unicellular
Photosynthetic
Basis of many aquatic and marine food webs
Protective coats made of silica or calcium carbonate
Shell-like part
Protist, but usually grouped in algae group
Types of Algae:
Green, Red, and Brown
Green Algae
Phylum Chlorophyta
Unicellular or multicellular
Habitats:
Water and Damp Soil
Red Algae
Phylum Rhodophyta
Multicellular
Habitat:
Deep, warm ocean waters
Brown Algae
Multicellular Among largest organisms on Earth Habitats: Oceans and Coast Provide Shelter to other Organisms
Molds
Purpose: to keep reproducing Slime molds Cell walls made of chitin Form plasmodia Used to be individual cells When confronted with unfavorable conditions, they form durable spores that can withstand the conditions Water molds Cell walls made of cellulose (like plants!) Habitat Fresh Water Can be hazardous to plants/animals
Fungi
Use spores to reproduce Thread like bodies Made of long slender filaments called hyphae Dense group of hyphae Mycelium Non photosynthetic decomposers (Saprobes) Parasites Fungal cell walls Made of chitin
Mushroom Structure
Hyphae are loosely woven through the soil and tightly packed in the body of the mushroom
Hyphae form a tangled mass,
Often many meters long
Called a mycelium
In some fungi, hyphae also form rootlike structures
called rhizoids
Types of Fungi
Not photosynthetic Mushroom Yeast Unicellular Only type of fungi that is unicellular Used in bread and beer making Moldhi
Fungal Partnerships
Lichens:
An association between a fungus and a photosynthetic partner
Can survive in extreme environments
Mycorrhizae:
Algae or cyanobacteria
An association between fungi and the roots of nearly all plants
Fungal hyphae
Grow inside or around the plant root and out into the soil
Fungi and Humans
Fungi and Industry
Fungi used for:
Food, Medicines, Fuels, Pest Control
Fungi and Ecosystem
Decompose organic matter by:
breaking down and absorbing minerals from rock
Fungi and Disease
Cause disease: Absorb nutrients and produce toxins Dermatophytes (Fungi that affect skin and nail) many fungi produce dangerous toxins
Bacteria
Bacteria in your mouth > Animals on the planet
Over 4,000 species have been named
Each square centimeter of your skin averages about 100,000 bacteria
Kingdom Archaebacteria
Primitive prokaryotes Ancestors to eukaryotes Many (not all) live in extreme environments Methanogens Produce methane gas Cannot be exposed to oxygen Live at the bottoms of swamps sewage Our intestines Halophiles Live in high salt concentrations Thermophiles Live in high temperatures Found in hot springs, hydrothermal vents Cells walls lack peptidoglycan
Niches of Bacteria in Nature
Decomposers Most bacteria species are decomposers Recycle nutrients so producers can use them Pathogens (“Disease Causing”) Mutualistic (mutualism) E.g., In human gut (digestive system) they help us digest and make some essential vitamins Make Vitamin B Vitamin K Nitrogen Fixers Cyanobacteria and Rhizobium Photosynthetic Cyanobacteria Chemoautotroph E.g., in deep sea vents (convert H2S into C6H12O6)
Bacteria Structure
Cell walls of kingdom bacteria contain peptidoglycan Gram stain measure how much Looks purple once stained Test helps to select antibiotic treatment Found in Three Forms Named based on shape Bacillus Pill rod Streptobacillus Chains In a row Staphylobacillus Clump of cocci grapelike/ cluster Coccus Sphere Streptococci Chains In a row Staphylococci Clump of cocci grapelike/ cluster Spirillum Spiral
Bacterial Reproduction
Asexual Binary Fission Splits into two Exact Copies Transformation Way to increase genetic variation Takes up foreign DNA Usually plasmids Plasmids - extra small pieces of DNA Might be something beneficial for them in foreign that DNA Interesting ways to increase genetic variation Always DNA around Bacterial Conjugation Increase genetic variation Pili - straw like appendage Swap pieces of DNA through pili Usually swap plasmids Easier to keep in Closest thing they have to sex
Viruses
No metabolism No growth No homeostasis Can evolve Can reproduce, but not on their own Host cells are required Take over host DNA polymerase makes more virus DNA RNA polymerase Ribosomes Genetic material in protein coat
Virus Structure
Contain nucleic acids DNA or RNA Surrounded by a protein coat Called capsid May also have an envelope and/or tail fibers Some are used in research and medicine Some are harmful Some are harmless
Viruses and their Hosts
Some kill their hosts quickly Others can infect live hosts for long periods of time Vaccines stimulate the immune system to protect itself Examples of Viruses Common Cold Rhinovirus Flu Influenza virus Smallpox Measles HIV Human Immunodeficiency Virus Immune system becomes extremely weak Can Cause Aids In the last stage of the virus Hepatitis Multiple Varieties HPV Human Papillomavirus Transmitted through sexual contact Some versions can cause cervical cancer On T cells Mono Kissing Disease Transmitted through saliva
Viral Reproduction
1) virus attaches to a bacterial cell and injects DNA
2) viral DNA enters the lytic cycle or lysogenic cycle
Lytic Cycle
3) new viruses are made inside the bacterial cell
4) cell breaks open and releases the viruses
5) process starts over again
Lysogenic Cycle:
3) viral DNA integrates with host DNA. the combined DNA structure is called a provirus
4) host cell divides normally and reproduces the viral DNA along with its own
5) provirus may enter the lytic cycle
Vaccines
Dead or weakened bacteria are injected or taken orally (by mouth)
E.g. Flu Shot
The person’s immune system builds up an army of white blood cells that respond to that type of bacteria
When the real bacteria comes along, the body fights it off before the person gets symptoms
Vaccines stimulate the growth of antibodies (proteins) that will target molecules found in the vaccines in order to fight it off later
Vaccines can be made for viral diseases
Leaves
Cuticle Waxy material Ground tissue Has mesophyll cells Lots of photosynthesis Low epidermis Lower part of leaf Upper epidermis Higher part of leaf Vascular bundle Vein Guard cells Surround stomata Guard the amount of water loss through the stomata Chloroplasts Outside of stomata Stomata Openings Pores Holes Oxygen come in and out from hole Surrounded by guard cells Swell up and pop out making stomata open Or close the stomata so water does not ‘escape’ Many types of Leaves Compound Has leaflets Have ‘veins’
Plant Classification
Nonvascular Plants, Seedless Vascular Plants, Nonflowering Seed Plants (gymnosperms), Flowering Seed Plants (angiosperms)
Nonvascular Plants
Moved onto land Phylum Bryophyta Mosses Phylum Hepatophyta Liverworts
Seedless Vascular Plants
Evolve vascular tissue Have Roots Have Stems Have Leaves Still reproduce via drought-resistant spores Phylum Lycophyta Club mosses Spores produced in a cone-like structure Live in swamps, tropics Phylum Pterophyta Ferns Produce spores under their leaves Found mostly in tropics
Nonflowering Seed Plants (Gymnosperms)
Evolved seeds Cones Male parts Pollen Female parts Big, huge Pollinated by wind for the most part Phylum Ginkgophyta Ginkgoes Ancient trees of the dinosaur era Phylum Coniferophyta Conifers Needle-like leaves reduce water loss Includes oldest and tallest of living trees Phylum Cycadophyta Cycads Short stems and palm-like leaves Phylum Gnetophyta Gnetophytes Trees, shrubs, and vines Seeds produced in flower-like structures Used to make ephedra
Flowering Seed Plants (Angiosperms)
Phylum Anthophyta Evolved flowers Produce seeds within protective fruits Most successful plants Important food source for humans Often evolved alongside animal pollinators Divided into monocots and dicots Monocots One cotyledon Leaves with parallel, straight veins Flowers part in multiples of 3 Vascular bundles scattered in stem Fibrous root systems Dicots Two cotyledons Leaves with branching veins Flower parts in multiples of 4 or 5 Vascular tissues in ring in stem Taproot system
Photosynthesis
Sunlight Carbon Dioxide Water Oxygen Plant waste Glucose Glucose + Glucose+ Glucose = Plant cells
ATP (Adenosine Triphosphate)
Energy currency of the cell
Why ATP is useful as energy currency:
Small amounts of energy
Energy is easily and quickly spent and recharged; provides energy “right now!”
ATP Supplies Energy for:
ATP → (can recharge)ADP (uncharged) + energy (which is used) + P A-P-P-P (charged, usable) --> A-P-P (uncharged) + energy + P Adenosine Triphosphate Active transport Movement Building new molecules When energy is needed ATP → ADP+P= energy for cell activity
ATP vs Glucose
Glucose is used to make ATP
1 Glucose stores 90x the energy of ATP
ATP efficiently transfers energy into the small amounts needed by the cell
ATP is only for very short-term storage (seconds)
ATP keeps getting “recharged’
Why are plants green?
Chlorophyll Bacteria is good at absorbing other colours other than green Green is reflected Green because of this 80% of green light is collected Absorbs other colours well Blue and red particularly Why Chlorophyll? Helps spread nutrients and energy Sugar photosynthesis
Chloroplasts
Aquatic Plant Visible cell wall Each cell has multiple chloroplasts The structure Cytochlorplasts Thylakoid Membrane-covered sacs Where light-dependent reactions occur Outer membrane Chlorophyll molecules Inner membrane Stroma Where Calvin Cycle takes place Chloroplasts cytoplasm outside the gram Lumen “Thylakoid’s Cytoplasm” Inside of thylakoid Granum Stack of thylakoid Membrane covered sacs thylakoid on membrane chlorophyll molecules
Steps of Photosynthesis
1. Light Reactions (Light Dependent) Inputs: Light and water come in Outputs: Oxygen Energy stored in ATP and NADPH Involves Water Light ATP & NADPH Energy molecules are charged and ready for use 2. Calvin Cycle (Light Independent) Inputs: CO2 Carbon dioxide gas Energy stored in ATP and NADPH Outputs: Glucose NADP+ ADP + P Factors that affect the rate of photosynthesis Carbon dioxide More CO2 Lots of glucose Happens faster Light Intensity More light Heat Increases making things faster Temperature Increased temperature Little increase Faster Big increase Not good Decreased temperature Slower
Kingdom Plantae Characteristics
Multicellular (mostly) Photosynthetic Autotrophs First organisms to move onto land Non-locomotive Unique cell walls Dominant Land Organisms Based on Weight Vary greatly in size Algae are NOT plants No tissues
Plant Structure
Tissue: Vascular- Not present in more primitive plants Strands of cells that carry fluids and dissolved nutrients throughout a plant Two kinds: Xylem: Carries water and minerals upward Transpiration, cohesion, and osmosis Made of dead tissues; “little straws” Phloem: Carries sugar upward or downward Sugar is produced from photosynthesis Made of living cells, Dermal ‘Tissue’- Covers the outside of the plant’s body Covers roots, stems, and leaves Epidermis in nonwoody plants Secretes the cuticle Helps roots absorb water Outer covering Cork in woody plants Composed of several layers of dead cells Core part, Ground- Any tissue that is not dermal, vascular, or meristematic Site of photosynthesis and food storage Most of the plant’s “insides” “Meaty” part Cortex and pith Pith - center Cortex - outside, Meristematic- Regions of new plant growth Located at tips of stems, branches, and roots Cells are alike at first, then differentiate Two types of growth: Primary Plants grow up and down Length growth Secondary Plants growth in thickness Girth growth, Shoots and roots- Adaptations for living on land Shoots: Above ground parts of plant Roots: Below Ground Anchor plant Store Food Absorb Nutrients, Stems- Support leaves Contain vascular tissues Can be woody or nonwoody Includes: Nodes Connect stem and branch Internodes Between two nodes Petioles Branch branching off, Leaves
Angiosperm Reproduction
Ovule: Female reproductive part Pistil Stigma: Sticky thing that catches pollen Style Ovary: Holds the ovule Stamen: Male reproductive part Anther Filament Petal: Attracts animal pollinators
Plant’s Behavior
Have hormones: AUXINS- Promote plant growth Can inhibit growth of lateral buds, GIBBERELLINS- Stimulate stem elongation, fruit development, and seed growth Growth in general Important in agriculture Important commercially Makes fruits “big, fat, and juicy”, CYTOKININS- Stimulate cell division Slow the aging of some plants Commercially significant Add cytokinins to fruits and flowers to slow aging Can last longer, ETHYLENE- Promotes the ripening of fruits Release Ethylene Gives a ripened smell Produced by rotting fruits, ABSCISIC ACID- Prevents seed growth under unfavorable conditions Allows plant to stop seed growth in winter Causes stomata to close
Environmental Influences on Plant Growth
Tropisms Growing towards \_\_\_\_\_ Gravity Touching Something Else Sun Phototropism Heliotropism Turn towards sun as it crosses the sky Growing toward the light of the sun Gravitropism Due to Gravity Positive or negative Going up or down E.g. trees & shoots almost always grow up E.g. roots almost always grow down Thigmotropism Found in vines Swing until they can touch something Then grow around it Photoperiodism Different light exposition Growth due to different forms of light Some plants thrive in little light Others in lots of Light Light in varying amounts Different results Amounts of light that plants need Temperature Dormacy Change in leaf colour Leaf dropping Not budding Plants tend to like warm weather Nastic movements Plant movements not controlled by the direction of a stimulus E.g. Venus Fly Trap Quick, reflex movement
