Life
SBI3U-Unit 1 Structures (Diversity in Organisms)
Classifying Organisms
What is the Difference Between a Spore and Gamete?
-The difference between a spore and a gamete is that a spore will germinate and develop into a sporeling, while a gamete needs to combine with another gamete to form a zygote before developing further.
Protista:
-Most organisms in the Kingdom Protista are unicellular, while some are multicellular. Some of these organisms are made up of very complex cells, while others are less complex. The most unifying feature of protists is that they all vary greatly from one another!
-In general, all protists are aquatic, and many species can live within the fluids of other organisms in a parasitic relationship.
-Malaria is an example of a parasitic protist causing human infection.
-Gas exchange will simply occur through direct diffusion between the cell body and the environment.
-When it comes to reproduction, feeding strategies, etc., there are a number of different methods used by the main species within this kingdom
The organisms of Kingdom Protista are divided into groups based on similar characteristics.
The three main groupings are animal-like, plant-like, and fungus-like.
Animal-like protists:
These organisms are considered animal-like due to the way they ingest food from their surroundings. Examples include Amoeba.
Plant-like protists:
These organisms contain chlorophyll. Like plants, many of these organisms can photosynthesize. Example: algae.
Fungus like protists:
These organisms are decomposers and feed on dead organic material just like the species of the Kingdom Fungi. Examples include slime and water moulds.
Additional Vocabulary:
Spores:
Reproductive unit capable of giving rise to a new individual without sexual fusion.
Ascus:
A sac in which spores of sac-like fungi forms
Sporangia:
a structure in which spores are produced.
Pilus:
A pilus is a thin, rigid fiber made of protein that protrudes from the cell surface. The primary function of pili are to attach a bacterial cell to specific surfaces or to other cells.
Antibiotic resistance:
The ability of a bacteria to resist the effects of an antibiotic.
Plasmid:
Small DNA molecule sperate from the nucleoid.
Nucleoid:
Nuclear region that combines the bacterial DNA
Fungi
Fungi are eukaryotic, usually multicellular, and unlike plants, are heterotrophs.
They are saprophytes meaning they obtain there nutrients from dead organic matter.
-Fungi absorb this digested food through their cell walls via diffusion
-Fungi play a very important role of nutrient recyclers in ecosystems
Structure:
-The bodies of most fungi consist of hyphae, which are thread-like strands or filaments
-The hyphae are thin tubes filled with cytoplasm.
-These hyphae branch out as they mature, and form a tangled mass called a mycelium.
Reproduction:
Can involve both sexual and asexual stages
Fungi Phylum:
Zygomycota (case like fungi), Ascomycota (sac like fungi), and Basidiomycota (club like fungi)
1. Case-like fungi- These fungi are classified as case-like, as structures that resemble little cases called sporangia.
2. Sac-like fungi-characterized by a sac-like structure called ascus an that contains the reproductive spores of the organism.
3. Club-like fungi: The large cap or shelf we see on the fungi is the most identifiable feature of this group and is used for classification. Under the cap are a series of gills, each bearing thousands of club-like reproductive cells. Each of these cells produces several thousand spores.
Respiration:
Types of Bacteria and Relationship with Oxygen:
Obligate Aerobes:
Organism that needs oxygen to survive.
Obligate Anaerobes:
These bacterial species cannot live if oxygen is present.
Facultative Aerobes:
Species that can live with or without oxygen
Cellular respiration occurs on the bacterial plasma membrane. Simple diffusion is all that is needed for gas exchange since these unicellular organisms are always in direct contact with their environment.
Not all bacteria species require oxygen for cellular respiration.
Archaebacteria and Eubacteria:
These two kingdoms represent the prokaryotes (single celled organisms that do not contain a nucleus or any membrane bound organelle.
Eubacteria:
Although there are many species of bacteria, they all share a number of common characteristics.
1. All bacteria are prokaryotic, which means they lack any membrane-bound organelles, and that their genetic material is found in the cytoplasm as compared to being within a nucleus.
2.All bacteria are unicellular.
3.The DNA of bacteria is found within a single chromosome, called nucleoid. Many species have small, loop-shaped plasmids that carry a small amount of genetic material in their cytoplasm.
4. All bacteria reproduce asexually through binary fission.
Bacterial Shape:
1. Spirillum: Spiral or corkscrew shaped bacterial cell.
2. Bacillus: Rod shaped bacterial cell.
3. Coccus: Round bacterial cell
4. Diplo: a pair of cells.
5. A chain of cells.
6. Staphylo: a cluster of cells (looks like grapes)
Archaea:
-Archaebacteria are thought to be the oldest group of organisms on Earth.
-Archaebacteria are also famous for surviving in very extreme environments
Extreme Weather:
Methanogens:
-Low oxygen environments
-Can produce methane gas
Thermophiles:
-Can withstand high temperatures
-Can be found in geothermal areas
Psychrophiles
- Are capable of growth and reproduction in cold temperatures
Halophiles:
-Salt loving organisms that can survive in very saline conditions.
Dichotomous Key:
A tool used to classify organisms based on a series of choices.
Reproductive Strategies
Internal vs. External Fertilization
External:
-Gametes meet outside of the body.
-Requires: Large amount of gametes, and water.
-advantages: parents do not need to be in the same location
-disadvantages: less chance of fertilization
-examples: frogs and corals
Internal:
-Gametes join inside of the body.
-requires: specialized organs and mating rituals.
-advantages: greater chances of fertilization and lower number of gametes needed.
-disadvantages: parents must be in the same location at the same time.
-examples: birds and reptiles.
Vegetative propagation techniques:
Offsets:
This occurs when a small plant develops at the end of a cutting. Once the offset produces its own roots, it can be removed from the plant and potted in soil.
Side Shoot Cutting:
When placed in water, side shoot cuttings of tomato plants will sprout roots within one to two weeks. This shoot is ready for the soil.
Leaf Cutting:
Many leaf cuttings will sprout roots when left in water. Once the roots are established, the cutting can be placed in soil.
Bark Grafts:
This type of graft aligns the vascular tissue of both plants. The graft is then sealed and allowed to heal over.
Whip and Tongue Grafts:
This whip and tongue graft is similar to a bark graph, only both sections are of the same diameter. As with the bark graph, the sections are cut in such a way that the vascular tissues will line up and remain functional, even if they are of different plant species. These grafts are often wrapped with tape or rubber strips to seal them while they heal.
Additional vocabulary:
Haploid:
Having half the genetic information of a somatic or body cell of the organism.
Diploid:
The full chromosome number of a somatic or body cell
of the organism.
Meiosis:
A type of cell division that results in 4 gamete daughter cells.
Gametes:
Male or female cell containing only half the genetic information of a body of somatic cells.
Grafting:
Attaching the tissue of one plant to the tissue of another.
Stolon's:
modified stems that run
Rhizomes:
Modified stems that run underground
Somatic:
any cell or organisms other than reproductive cells.
Genetic continuity:
Continuation of genetic material of generations
Mutations:
A change in the message or trait carried by the genetic material.
Diversity: Variability among organisms.
Clone: and organism or cell produced asexually that is genetically identical to the parent.
Sexual reproduction:
Sexual Fertilization Methods:
Salmon Spawning: A classic example of external fertilization. The female deposits her eggs in a small depression, and the male releases the sperm over the eggs.
Coral Spawning: The sperm and egg cells are released at the same time one night of the year based on temperature and moon cues.
Earthworm Mating:Hermaphroditic worms couple in order to fertilize the eggs that each individual carries. The sperm is deposited into the slime tube that forms around the worms, and the eggs are then fertilized after the mating has finished.
Tree Pollen Explosion: Pollen from the male cones of cedar trees is released into the air to be captured by the female cones.
Clownfish Gender Change: The female clown fish is at the top of the hierarchy, so when she dies, a male changes gender to female to take her place.
-In some cases, both male and female gametes come from the same individual. Individuals that can produce both male and female gametes are called hermaphrodites.
-Most plants and some animals (mostly invertebrates), like earthworms and molluscs, such as snails, are hermaphroditic
-Sexual reproduction results in genetic variety and diversity. In this form of reproduction, individuals are produced from the fusion of two sex cells or gametes.
-The offspring are therefore not genetically identical to just one of the parents, as the genetic material comes from two different sources.
Asexual reproduction
Forms of Asexual Reproduction:
Binary Fission:
Two parent cells undergo cell division to create two genetically identical individuals. Examples include the prostist Amoeba.
Budding:
A form of asexual reproduction in which a new individual develops from some generative anatomical point of the parent organism. Examples include yeast.
Vegetative Propagation:
The process in which new plants are grown from the old parts of another plant like roots, shoots and leaves, without involving any reproductive organ. Examples, non-vascular moss.
Fragmentation:
The body of the parent breaks into two or more pieces and each piece has the ability to generate the missing parts and form a new genetically identical individual. The original parent is lost in the process. Example, sea star.
Spores:
Reproductive cells that contain identical genetic information to the parent. Example, mushrooms.
The production of cells:
mitosis: Part of the cell cycle where replicated chromosomes are divided into two genetically identical daughter cells.
-This process allows a single organism to pass on its genetic information from one generation to the next. Since this reproductive strategy only involves a single parent, the genetic material passed on is identical to the parent organism.
-This cloning produces generations of organisms with identical or very similar traits: the continuity results in very little variation throughout the generations.
-Asexual reproduction will often produce a large number of offspring in a short amount of time. Bacteria is an example of this.
Transport Within Organisms
Transport within Animals:
The three types of circulatory systems:
Open: Blood is pumped into body cavities, where the tissue's are surrounded by the blood.
Double: Blood circulates through two vessels, the systemic or body, loop or pulmonary loop.
Single: single loop of vessels in which blood circulates.
All four main types of animal tissues (epithelial, connective, muscle, and nervous tissue) are associated with the arteries and veins.
The role and impact of the 4 tissues:
Epithelial:
made up of layers of tightly packed cells that line the surfaces of the body for protection, secretion, and absorption. They play a key role in controlling blood flow. The layer is only one cell thick, so oxygen and other small molecules can diffuse through.
Muscle Tissue:
The smooth muscle layer in vessels is the main support, and regulates the diameter of the vessels. The diameter of the vessels plays an important role in blood pressure. The smooth muscle is thicker in the artery.
Connective Tissue:
The outer layer of both vessel types is made up of connective tissue. This layer adds structure to the vessels, but also connects them to surrounding tissue and holds them in place. The connective tissue helps keep the vessels positioned for optimal blood flow.
Nervous System:
Although nervous tissue does not make up an actual layer of the blood vessels, it is still associated with arteries and veins. Dilation and constriction of blood vessels is in some part controlled by the body’s nervous system. When you become startled, the nervous system will send a message to dilate the vessels. This dilation drops blood pressure.
The animal system has specialized tissues and structures in order to circulate blood, gases, and other nutrients around the body.
Non-Vascular Plants:
Plants without vascular tissue. These plants don’t have xylem, so they are located in damp areas. Instead of using their roots to draw up moisture, each cell obtains its water through osmosis directly from the environment. Finally since they don’t have phloem, sugars cannot be transported around the plant, each cell needs the ability to undergo photosynthesis to create the sugars it requires. Non-vascular plants do not have leaves.
Examples: mosses, liverworts, and hornworts
Additional terms
Osmosis:
The movement of water molecules from an area with a high concentration of water molecules to an area with a lower concentration of water molecules.
Active transport:
Movement of molecules across the cell membrane against the concentration gradient. This requires energy.
Cohesion:
When water molecules stick together.
Adhesion:
The action of water sticking to other substances.
Transportation:
The process of water movement through a plant
and its evaporation from the leaves, flowers, and stems.
Transport within Plants
Dead cells are the key to transport in plants
Phloem:
Vascular tissue in plants that transports sugars from the leaf to other parts of a plant. Sieve tube cells are the main structure of the phloem, they are narrow and have pitted ends resembling small sieves. All the cells in the phloem tissue are alive and these cells do not have a nucleus (at maturity).
Companion cells:
A type of cell that regulates the activity of the sieve tubes.
Sugars are transported in the Phloem through active
transport, diffusion, and osmosis.
Xylem:
Vascular tissue in plants that transports water and nutrients up from the roots to the leaves of a plant. The cells in the tissue are all dead. There are 2 types of Xylem cells...
Tracheid:
The tracheid's are narrower than vessel elements. Another difference is that tracheid's are found in all types of vascular plants and not just angiosperms. It is a type of water conducting cell that is found in plants at maturity when they die. The walls of these cells become rigid due to deposits of lignin (an organic molecule deposited in the cell of many plants) and cellulose (insoluble substance made from glucose).
Vessel elements:
The vessel elements are only found in angiosperms. It is the water conducting tissue of plants.
Main topic
Diversity in Gas Exchange
Gas Exchange and Ventilation Disorder
A number of diseases and disorders can have an impact on ventilation and the gas exchange process. These include things such as asthma.
Alveoli:
(This can be found in the lungs of humans as well)
Tiny sacs within the lungs that allow for gas exchange of oxygen and caron dioxide between the lungs and the bloodstream.
Capillary:
Vessels that form the connection between the arteries and the veins.
Semipermeable:
-It is a membrane that only allows certain molecules to pass via diffusion.
-Thin walls in the alveoli that are surrounded by tiny blood vessels
Diffusion:
Diffusion is used to move particles from an area of higher concentration to an area of lower concentration. It is this concentration gradient that allows the oxygen to enter the cells. This process does NOT require energy.
Aerobic cellular respiration:
The process of producing cellular energy when
glucose reacts with oxygen to produce carbon dioxide and water.
Vascular Plants
The leaves (where gas exchange occurs)
The layers of a leaf
Upper epidermis:
Outer layer of plant, prevents water
loss and protects tissue.
Palisade Mesophyll:
Composed of cells that are tightly packed and elongated in order to capture as much energy from the Sun as possible
Spongy Mesophyll:
Loosely packed to allow air to circulate around them to facilitate gas exchange. The term means inner or middle tissue.
Lower Epidermis
Vein:
The bundles of vascular tissue that allow the transport of water and dissolved nutrients throughout the plant
Guard Cells:
control the opening of the pores
Stoma:
Pores that allow gas exchange between the atmosphere and the inner tissues of the leaf
The tissue systems
Vascular:
Transports food, water and nutrients. It is composed
of the xylem and phloem tissue.
Ground:
Preforms photosynthesis, stores food, regenerates supports, and protects. It consists of the parenchyma, collenchyma, and sclerenchyma tissues.
Dermal:
Form of protection and prevents water loss.
The shoot and root system:
-The shoot system is comprised of the organs found above the ground, namely stems and leaves. The shoor undergoes photosynthesis, transports food and water, reproduces and acts as a form of storage.
-The root system is found below the ground, and includes all the root material. The shoot absorbs water and minerals, transports food and water, and reproduces.
Angiosperm:
Vascular plant that produces flowers
Monocots vs. Dicots:
-Are the two major groups of angiosperms.
-The name is based off the number of cotyledon (the first part of a plant to emerge from the seed).
-Monocots: contain 1 cotyledon, have long narrow leaves with parallel veins, the contain scattered vascular bundles, and their flowers part in multiples of three.
-Dicot: 2 cotyledon, broad leaves that contain networks of veins, have vascular bundles in rings and their flowers part in multiples of 4 or 5.
Photosynthesis
Process by which certain plants use sunlight to synthesize food from carbon dioxide and water.
-It is the process where light energy is trapped in a plant's chlorophyll and produces sugars.
-The process helps bring oxygen into the atmosphere.
Greenhouse effect:
The trapping of the summers heat in the earth's lower atmosphere due to greenhouse gases like carbon dioxide.
Why Classify?/The Variety of Life
Feeding Strategies
Heterotroph:
An organism that is unable to synthesize its own nutrients, to receive nutrients it must take organic substances from other organisms
Autotroph:
An organism that has the ability to synthesize it own nutrients from inorganic substances
Classification
Phylogeny: the evolutionary history of a group of organisms. Organisms can be classified in a phylogenetic tree.
Niche: the role or function of an organism plays in a ecosystem/community
ex. a bird's niche might be to provide food for their family
Uni Cellular:
Organism composed of one cell
Bacteria
Multi Cellular:
Organism composed of two or more cells
Animals
Plants
Taxonomy
Taxonomy Hierarchy
Domain: the most general rank of organisms in a taxa
Kingdom: Second most general taxonomic rank
Phylum
Class
Oder
Family
Genus: A ranking of species that are structurally related.
Species:
Most specific rank of organisms. It a group of closely related organisms, they share similarities such as the ability to interbreed and produce fertile offspring.
Taxonomists:
A person who specializes in classifying and sorting information about organisms
Carl Linnaeus:
A Swedish botanist, physician, and zoologist who created the naming system (Linnaean binomial nomenclature)
Botanist:
A person who studies all plant life
Linnaean binomial nomenclature:
An organism naming system
