Biology: Preliminary Module 1: Cells the Basis of Life

Inquiry question: What distinguishes one cell from another?

1. CELL Cell Theory: All cells are the basic theory of the structure and functional units of life formed by pre-existing cells by cell division.

1. All things are made of cells 2. The cell is the smallest unit of life 3. All new cells come from preexisting cells

Types of Cells Eukaryotic cells - Size 10 - 100mm

➔ Are more complex and contain an array of membrane bound organelles

➔ Membrane bound nucleus ➔ Paired chromosomes ➔ Could be single celled or multi celled

Prokaryotic cells - 2.5mm

➔ Are more simple, and do not have membrane bound organelles

➔ No nucleus ➔ Bacteria ➔ Only unicellular

Bacteria

➔ Exists only as unicellular organism ➔ Some photosynthesis or chemosynthesis; others absorb it from outside cell ➔ Contain a cell wall ➔ Bacteria and cyanobacteria e.g. E, coli, staphylococcus

Archaea

➔ Only exists as unicellular and reproduce by asexual reproduction ➔ Prokaryotic and have cell wall

Fungi

➔ Exists mostly as multicellular organisms and reproduce sexually or asexually ➔ Absorb food from their surrounding

➔ Eukaryotic and contains a cell wall

Plant ➔ Exists as multicellular organism and reproduces sexually or asexually ➔ Produce food by photosynthesis ➔ Eukaryotic and contains a cell wall ➔ E.g. flowering plants and ferns

Animal

➔ Exists as multicellular organisms and reproduce sexually ➔ Ingests food for nutrition ➔ Eukaryotic, no cell wall

The Structure of Membranes in Cells : The Fluid Mosaic Model The cell membrane controls the exchange of material between the internal and external environments of the cells. The structure of the cell membrane allows the concentration of substances inside to remain fairly constant and different from the external environment. The fluid mosaic model describes the cell membrane as a double layer of lipids (a lipid bilayer) with the ability to flow and change shape, like a two dimensional fluid. Both proteins and phospholipids help to control the exchange of materials between external and internal environments.

The lock and key model: For an enzyme to catalyse a reaction, the small substrate molecules must temporarily bind to the active sites. The active site is rigid and the small substrate molecule is reciprocally shaped and fits into the active site, like a lock fits a key.

Inquiry question: What distinguishes one cell from another?

2. TECHNOLOGIES FOR STUDYING CELLS - MICROSCOPY Types of Technology

1. Dissecting Microscope ➔ Dissecting Microscope uses both light and lens. Light will reflect up

through the objective lens to the second lens known as either eyepiece or octagon lens

2. Compound Light Microscope ➔ Compound Light Microscope has a light source that will shoot up to the

objective lens through the eye lens 3. Scanning Electron Microscope

➔ Scanning Electron Microscope instead of lights and scanning electron microscope uses electrons to view specimens you wouldn’t be able to look directly through an eyepiece you would have to use a computer and attach it to the microscope

4. Transmission Electron Microscope ➔ Directs a beam of electrons at specimens creating an image based on

an electron that are absorbed Microscopes Dissecting Microscope Scanning Electron

Microscope Transmission Electron Microscope

3D Image 3D Image 2D Image

2 light sources 1 focused light source 1 illumination source

nification 20x-30000x Magnification

2000x-10000000x Magnification

Used for circuits/dissects

Used for bacteria/viruses Used at molecular level.

Inquiry question: How do cells coordinate activities within their internal environment and the external environment?

- conducting a practical investigation modelling diffusion and osmosis

Movement of molecules across cell membranes The permeability of a cell membrane to a molecule depends on the:

➔ Size: small molecules can move across membranes more quickly than large molecules

➔ Water is a polar molecule and is not lipid-soluble

➔ Molecules that have low permeability rely on carrier proteins to transport them across membranes in cells

Diffusion The transport of materials into and out of the cell can be either passive or active transport. Passive movement requires no energy input and includes the process of diffusion and osmosis.

➔ Diffusion is the net movement of any molecules from a region of high concentration to a region of low concentration of substance until equilibrium is reached.

➔ The rate of diffusion is dependent on the concentration gradient. ➔ Diffusion can also speed up or slow down depending on the temperature

Osmosis Osmosis is a type of diffusion. It is the net movement of solvent molecules from a region of high solvent concentration to a region lower solvent concentration through a semipermeable membrane.

➔ Water moves through Aquaporin the channel ➔ Hypertonic: Solution with higher concentration of water than cell.

Active transport The movement of molecules from a low concentration to a high concentration through selectively permeable membrane.

➔ From an area of low solute concentration to an area of high solute concentration

➔ Moves against the concentration gradient. ➔ Energy is required

Module 2: Organisation of Living Cells 1. Organisation of Cells

Inquiry question: How are cells arranged in a multicellular organism? Compare the differences between unicellular, colonial and multicellular organisms:

- investigating structures at the level of the cell and organelle - relating structure of cells and cell specialisation to function

Is a Blue Bottle one Organism?

➔ Dactylozooids - Zooids that attach to prey and secrete various digestive system

➔ Gonozooids - Each one consists of male and female reproductive bodies

➔ Gastrozooids - A trailing tentacle that has specialised stinging cells to assist in trapping

➔ Pneumatophore - An air-filled bladder that helps the blue bottle float

2. Do you think blue bottles should be classified as colonial organisms or multicellular organisms? Justify your opinion. Blue bottle are classified as a colonial organisms due to it containing many individual zooids that live together in large amounts. “Blue bottles are not a single animal but a colony of four different specialised polyps and medusae fused together.” Ocean adventure provides more insight into the details of blue bottles. Inquiry question: How are cells arranged in a multicellular organism?

- Investigating structures at the level of the cell and organelle Unicellular organism: Eukaryotic / Prokaryotic

- Complete living entity consisting of just one cell. Its survival is not dependent upon other cells.

- May divide into two parts, each part unicellular and independent

Colonial organism: Eukaryotic - Collection of Unicellular Organisms living together. - Difference to a multicellular organism is that if separated,

the individual one celled organisms can survive on their own.

Multicellular organism: Eukaryotic / Prokaryotic

- Organisms that are made up of more than one cell. - Consist of specialised cells that perform different tasks

within the organism. - All the parts are required for the organism to survive and

individual cells cannot survive alone. 1. Identify 3 domains of life

- Archaea - Bacteria - Eukaryotes

2. Domains do you find unicellular, multicellular and colonial life forms? Multicellular: Eukaryotes found in animals, plant, fungi and Protista kingdoms Unicellular: Archaea and Bacteria are prokaryotes and do not contain membrane bound organelles example, nucleus were the first forms of life Colonial: Can be unicellular example, some flagellates such as the volvo acid or multicellular

- Relating structure of cells and cell specialisation to function Specialisation and Differentiation Specialisation: - Cells are specialised ‘DO’

❏ Carries out a specific job to benefit the whole organism Differentiation: - Cells are differentiation ‘LOOK’

❏ Cells are instructed by genetic information to change their structure, they are differentiated from their original form

2. Organisation of Cells Inquiry question: What is the difference in nutrient and gas requirements between autotrophs and heterotrophs? Cell Specialisation in Life Forms Autotrophic Nutrition

➔ Autotrophs are living things that can supply their own food and organic molecules.

❏ Can be photoautotrophs using carbon dioxide and sunlights for energy in photosynthesis

❏ Chemoautotrophs using carbon dioxide as the source of carbon and energy from oxidising inorganic substances.

Heterotrophic Nutrition ➔ Heterotrophs are organisms that depend on other organisms as sources of

food and can be unicellular ➔ Multicellular heterotrophs need to be able to find and catch other organisms to

consume energy. Specialised Structures in Multicellular Organisms

➔ Organ Systems are made up of a group of body organisms working together ➔ Multicellular organisms have a smaller Surface Area to Volume Ratio than

Unicellular ➔ Multicellular organisms are too large for materials to enter cells with diffusion,

rely on specialised transport systems to carry substances around. Examples include:

❏ Respiratory Systems ❏ Reproductive Systems ❏ Excretory Systems

Inquiry Question: What is the difference in nutrient and gas requirements between autotrophs and heterotrophs?

- Investigate the function of structures in a plant, including but not limited to: tracing the development and movement of the products of photosynthesis

Dicot Root Longitudinal Transverse Cross Section

Leaves

➔ In leaves Mesophyll tissue carries out Photosynthesis ➔ The chief function of the epidermis of a leaf is protection of internal tissues

from excessive water loss ➔ Some climbing plants have leaves modified into tendrils that curl around

nearby structures as the plant grows, the benefit of the modification is that is helps the plant reach higher to catch more sunlight

➔ Stomata will close even if the conditions are suitable for photosynthesis to avoid water loss and keep gas levels high

➔ Guard cells will close up to keep water inside and will only open when there is enough water for photosynthesis

Transport in Plants Xylem Vessels

➔ Water carrying pipes of the plant. ➔ Formed from the empty remains of dead cells ➔ Walls coated with a woody substance called lignin to support the stem.

Cambium ➔ Consists of cells able to divide to produce more cells ➔ These tissues are called meristems. ➔ Form extra Xylem and phloem cells making both stronger

Phloem ➔ Made up of living cells ➔ Called sieve tubes and companion cells ➔ Sieve tubes transport the sugars ➔ Sieve plate:

❏ End wall of the sieve tube, has holes to let sugars pass from one cell to the next.

➔ Sieve Tubes: ❏ Long Tube joined end to end

❏ Carry sugar ❏ Living cells which from them have thin cytoplasm and no nuclei

➔ Companion Cells: ❏ Thick cytoplasm and large nuclei ❏ Do not carry sugar but aid Sieve tubes in doing so

➔ Source: Where the material starts its journey/ where it is first produced. The

leaf produces Glucose ➔ Sink: Where the material finished its journey ➔ Osmosis: The process of moving water from high concentration to low

concentration. ➔ Translocation: Transport of soluble food material one plant to another via

phloem or xylem. ➔ Xylem Vessels: Water carrying pipes formed by dead cell remains, wall

coated with lignin ➔ Transpiration: The passage of water through a plant from the roots through

the vascular system to the atmosphere ➔ Capillarity: Movement of a liquid, through a narrow space as a result of

cohesion, adhesion and surface tension, going up ➔ Cohesion: The act, state or process of sticking together, as in intermolecular

force that holds together alike molecules in a substance or the binding of alike molecules

➔ Adhesion: The binding of a cell to another cell, or a cell to a surface, via specific cell adhesion molecules

➔ Tracheids: Tubular cell in xylem of vascular plants whose primary function is to conduct water and mineral salts, provide structural support and prevent air embolism in vascular plant.

Diffusion and Osmosis

Diffusion Osmosis

Selectively permeable membrane involved

Not necessarily/ Not always

Yes

Substances that are moved

Any dissolved or suspended substance

Water

Direction of movement of substance

From a space of higher concentration of dissolved solute to one with a lower

From a space with higher cof water to one with a lowerconcentration of water

concentration of said solute

Investigate the gas exchange structures in animals and plants through the collection of primary and secondary data and information.

● microscopic structures: alveoli in mammals and leaf structure in plants

Respiratory Systems and Gaseous Exchange in Animals ➔ Gills: A respiratory organ found in many aquatic organisms; it extracts

dissolved oxygen from the water and excretes carbon dioxide. Possessed by fish.

➔ Tracheal System: The system in insects where the oxygen and carbon dioxide are exchanged by a system of tubes (called tracheae) that open to the outside through small holes (called spiracles). Possessed by Insects

➔ Alveoli: Air sacs in the lungs through which oxygen and carbon dioxide are exchanged between the blood and the air. (Singular: alveolus). Possessed by Mammals, Human.

➔ Gas exchange: The movement of oxygen and carbon dioxide in different directions across a membrane.

Name of Organism

Description of respiratory surfaces

Are respiratory surfaces in close contact with Blood vessels?

Are respiratory surfaces located internally or externally

How respiratory surfaces are kept moist?

Mammal Lungs Yes Internally Mucus

Fish Gill Yes Externally Water

Insect Trachea No Internally Hemolymph

Frog Skin Yes Externally Environment

● macroscopic structures: respiratory systems in a range of animals

Human Digestive System

Part of a digestive system

Function

Teeth Physically break up food into small pieces

Salivary Glands Produce an enzyme which start the chemical breakdown of starch into glucose

Oesophagus Carries food from the mouth to the stomach

Stomach Produces hydrochloric acid and an enzyme called pepsin which breaks protein down into amino acids

Small intestine Secretes enzymes to digest food. Completes the digestion of food absorbs digested food through its wall into blood vessels and lymph vessels

Large intestine Undigested food passes out of the body as faeces. Absorbs water and some vitamins

Anus Ring of muscle at the end of the large intestine. Controls the release of Faeces.

Liver Produces bile which breaks up fat into small droplets so they can be digested.

Pancreas Produces enzymes to digest food in the small intestine

Gallbladder Stores bile until it is needed.

Trace the digestion of foods in a mammalian digestive system, including:

- physical digestion - chemical digestion - absorption of nutrients, minerals and water

Mechanical Digestion: The physical aspect of digestion, biting, chewing and grinding by the teeth Chemical Digestion: The chemical aspect of digestion, saliva, bile, stomach acid, enzymes.

3. Transport Inquiry question: How does the composition of the transport medium change as it moves around an organism? Investigate transport systems in animals and plants by comparing structures and components using physical and digital models, including but not limited to:

- microscopic samples of blood, the cardiovascular system and plant vascular systems

Cardiovascular System Deoxygenated Oxygenated Blood enters the HEART

➔ Deoxygenated Blood enters the heart through the Superior and Inferior Vena Cava ➔ Deoxygenated Blood travels into the Right Atrium.

➔ Deoxygenated Blood passes through to the Right Ventricle ➔ Deoxygenated Blood travel through the Pulmonary Artery the

only artery in the body that allows to blood pass through. ➔ Deoxygenated Blood enters into the Lungs for Gaseous

exchange at the lungs. Co2 - O2

➔ Oxygenated blood is released from the lungs and enters to the Pulmonary Veins

➔ Oxygenated blood travels into the Left Atrium.

➔ Oxygenated blood is taken through the Left Ventricle.

➔ The Aorta receive the Oxygenated blood.

➔ The Oxygenated Blood is released into the Body to get the muscles.

Human Blood Made up of: Plasma

➔ Makes up 55% of the blood ❏ Proteins: Carry fats and hormones, help produce antibodies, e.g.

fibrinogen which is essential for clotting the blood in injury. ❏ Food, waste (urea) and minerals ❏ Gases: little amount of oxygen dissolves into the plasma. Carbon

dioxide dissolves easily in the plasma to form bicarbonate

Platelets

➔ Tiny packets of cytoplasm ➔ Job is to reduce bleeding when injured ➔ Help plug leaks ➔ Important for clotting of blood ➔ Work with plasma by breaking up the fibrinogen into fibrin which binds blood

cells together

Red Blood Cells ➔ Make up 45% of the blood ➔ Carry oxygen around the body ➔ To do this they carry haemoglobin. Iron is required in the blood for

haemoglobin. ❏ Lack of Iron is called anaemia

White Blood Cells

➔ Job is to fight sickness ➔ Two types of White Blood Cells

❏ Polymorphs - Have grainy cytoplasm and a nucleus divided into lobes. Kill

germs by phagocytosis ❏ Lymphocytes

- Make antibodies, cause germs to clump together and burst - Located in peripheral lymphoid tissues:

● Spleen ● Tonsils ● Lymph nodes

Module 3: Biological Diversity 1. Effects of the Environment on Organisms

Inquiry question: How do environmental pressures promote a change in species diversity and abundance? Predict the effects of selection pressures in ecosystems, including:

- Biotic factors - living (fungi, plants) - Abiotic factors - non living ( wind)

Biotic Factors Biotic selection pressures that affect ecosystems:

➔ Availability of food → low food availability = decreases in population + abundance

➔ Mates → able to find mate = reproduction + increase in population + abundance

➔ Predators → high amount of predators = decrease in prey population + abundance

➔ Competitors → high amount of competitors = competition for resources + decrease in population

Abiotic Factors Abiotic selection pressures that affect ecosystems:

➔ Temperature ➔ Oxygen availability → low oxygen = low respiration + decrease in organisms

that can inhabit the environment ➔ Water availability → low water = competition for water + decrease in

abundance species

Investigate changes in a population of organisms due to selection pressures over time, for example:

- Cane toads in Australia Cane Toads in Australia Introduced as biological control for cane beetle. No natural predators → +ve selection pressure, population increased. Increased food source of native fauna → +ve selection pressure. Toads became fast moving and directional due to spatial sorting → +ve selection pressure. Larger size and longer legs → +ve selection pressure. Development of arthritis in older, larger toads → -ve selection pressure. Overall population increase due to +ve selection pressures.

2. Adaptations Inquiry Question: How do adaptations increase the organism’s ability to survive? Conduct practical investigations, individually or in teams, or use secondary sources to examine the adaptations of organisms that increase their ability to survive in their environment, including:

- Structural adaptations Structural Adaptations Anatomical features that improve an organism’s ability to cope with abiotic and biotic factors in their environment. Appropriate adaptations increase the chance of survival and reproduction. Body shape and size are structural adaptations. Example: thick fur to survive the cold

- Physiological adaptations Physiological Adaptations Internal features of an organisms that enable them to survive in their environment. Example: camouflaging.

- Behavioural adaptations Behavioural Adaptations Actions that an organism takes to improve survival and reproduction. Example: seeking or leaving shade/ shelter. Investigate, through secondary sources, the observations and collection of data that were obtained by Charles Darwin to support the Theory of Evolution by Natural Selection, for example: Charles Darwin was an English naturalist. He collected specimens from every location. In 1858 Charles proposed a process by which evolution occurs called “NATURAL SELECTION”

- Finches of the Galapagos Islands During his visit he realised finches were similar on different islands and showed distinct variation in beak size and structure.

3. Theory of Evolution by Natural Selection Inquiry Question: What is the relationship between evolution and biodiversity? Explain biological diversity in terms of the Theory of Evolution by Natural Selection by examining the changes in and diversification of life since it first appeared on the Earth. Biochemical Evolution Theory – This theory suggests that certain conditions of Early Earth generated the organic compounds and the right environment for the first production of a living organism. Evidence to support this theory An anoxic atmosphere is one defined as being deficient or lacking in oxygen - Anaerobic An oxic atmosphere is one where oxygen is readily available - Aerobic

Analyse how an accumulation of microevolutionary changes can drive evolutionary changes and speciation over time, for example: Gene: Selection of DNA that codes for characteristic e.g. hair colour Allele: Different form of gene e.g. red hair Microevolution: Takes place over short periods of time; new forms that arise; example; breed of a dog Macroevolution: Takes place over millions of years; arising new species; example monkey and human

- Evolution of the horse Evolution of the horse is a microevolution

- Evolution of the Platypus Evolution of the platypus is a macroevolution because took a long time and on the way some species were speciated and new species were created. Explain, using examples, how Darwin and Wallace’s Theory of Evolution by Natural Selection accounts for:

- Convergent evolution Distinctly related species; shows similarities and moved into similar environment; exposed to similar selective pressure.

- Divergent evolution Share common ancestor; organisms moved to different habitats (exposed to new pressures) another name: adaptive radiation: radiation means spreading out and adaptive means change to their new environment.

Module 4: Ecosystem Dynamics Inquiry Question: What effect can one species have on the other species in a community? Investigate and determine relationships between biotic and abiotic factors in an ecosystem including:

- Impact of Abiotic Factors

Factors: Effect: - Temperature - Types of organisms - Oxygen Availability - Abundance (plants and animals) - Water Availability - Distribution (plants and animals) - Light intensity - Food availability - Buoyancy - Competition - Pressure - Niches

- Communities

- Impact of Biotic Factors; Including predation, competition and symbiotic relationships:

Biotic factors: Effect: - Availability of food - Abundance (plants and animals) - Competition for territory - Distribution (plants and animals) - Number of predators - Population structure of organisms. - Ability to find a mate - Disease + parasites

➔ Mutualism - Both species in relo beneficial (+/+)

➔ Commensalism - One species if beneficial and other unaffected. (+/0) one receiving benefit is called commensal and one that doesn’t get affected is called host.

➔ Parasitism - One species beneficial and other suffers. (+/-) one receiving benefit is.

- Predicting consequences for populations in ecosystems due to predation, competition, symbiosis + disease.

The part of the ecosystem that organisms occupies is called niche. Niche refers to all the resources that a species used. 3 Types of Niches

➔ Moderate interspecific (diff species) competition - realistic niche ➔ Intense interspecific comp- narrow niche ➔ Intense intraspecific (same species) competition - broad niche

Species that are intraspecific are usually more intense as the organisms have more resources common niche overlaps. Consequence of Competition Competition between species for resources affects reproduction and survival rates. If food sources decrease so may the abundance of both competing species. Consequence of Symbiosis Symbiosis contributes to:

➔ Increase in biodiversity ➔ Development if new species

Symbiosis allows increase in biodiversity and therefore more resilient ecosystems. Consequence of Disease Disease can be defined as any process that affects the normal functioning of the tissues in living organism.

- Measuring populations of organisms using sampling techniques

Capture-recapture technique used for mobile populations. Traps are set and species are caught, tagged and released. Later the process is repeated and then abundance is calculated.