Preliminary Biology NSW

Complete Preliminary Biology NSW Syllabus

Eukaryote

A cell that contains a nucleus and membrane bound organelles

Prokaryote

A unicellular organism that lacks a nucleus and membrane bound organelles

Cell wall

Surrounds plant, fungi and protist cells for protection

Cell membrane

thin, flexible barrier around a cell; regulates what enters and leaves the cell

Cytoplasm

All fluids and organelles contained by the membrane

Cytosol

Fluid portion of cytoplasm

Nucleus

A part of the cell containing DNA and RNA and responsible for growth and reproduction

Nucleolus

Found inside the nucleus and produces ribosomes

Endoplasmic Reticulum

Synthesises and transports materials. Rough ER synthesises protein and has ribosomes on the surface, smooth ER is free of ribosomes and produces lipids and steroids

Golgi apparatus

A system of membranes that modifies and packages proteins for export by the cell

Lysosomes

Cell organelle filled with enzymes needed to break down certain materials in the cell

Vacuole

A sac inside a cell that acts as a storage area

Ribosomes

Not membrane bound, synthesises proteins

Mitochondria

Stores and synthesises ATP. Powerhouse of the cell.

Chloroplasts

Contains chlorophyll, which traps energy from sunlight for photosynthesis and gives plants their green colour

Cytoskeleton

A network of fibres that holds the cell together, helps the cell to keep its shape, and aids in movement

Peroxisomes

Break down fatty acids and produce hydrogen peroxide

Plastids

A group of membrane‐bound organelles commonly found in photosynthetic organisms and mainly responsible for the synthesis and storage of food.

Cell theory

1. All living organisms are composed of one or more cells.
2. The cell is the basic unit of structure and organization in organisms.
3. Cells arise from pre-existing cells.

Fluid mosaic model

Describes the structure and function of ALL cell membranes --\> composed of a phospholipid bilayer

Facilitated diffusion

Diffusion of substances through the cell membrane via channel and carrier proteins. Does not require energy and goes along the concentration gradient

Simple diffusion

the movement of any molecule from high to low concentration until equilibrium is reached

Osmosis

The movement of water from a high concentration of water to a low concentration of water across a semi-permeable membrane

Cell membrane permeability

Permeable to small neutral molecules. Hydrophobic molecules will diffuse across the membrane easier.

Protein pump active transport

Specific carrier proteins embedded in the membrane bind with and are able to transport small charged molecules. Requires ATP.

Endocytosis

transport of matter into the cell using vesicles that engulf particles

Pinocytosis

Endocytosis of liquids. Engulfing liquids into the cell

Phagocytosis

Endocytosis of a solid. Engulfing solids into the cell

Receptor-mediated endocytosis

protein receptors trigger endocytosis of specific molecules

Exocytosis

Transport of matter out of the cell using vesicles.

Remember EX because you want to get far away from your ex lol.

Surface area to volume ratio

The greater the SA:V ratio, the faster diffusion will occur.

inorganic compounds

A compound that does not contain the element carbon or contains carbon bound to elements other than hydrogen. E.g. water, oxygen, mineral ions and carbon dioxide

organic compounds

Compounds that contain carbon. E.g. carbohydrates, nucleic acids, vitamins, lipids and proteins.

Ions

Charged molecules

Photosynthesis general equation

carbon dioxide + water --\> glucose + oxygen

Respiration general equation

glucose + oxygen --\> carbon dioxide + water + ATP

Light dependent stage of photosynthesis

In the thylakoid membranes of chloroplasts, it is the splitting of water and release of oxygen, production of ATP and storage of electrons

Light independent stage of photosynthesis

In the stroma of chloroplasts, using ATP produced in the first stage, and glucose is formed.

Enzymes

Biological catalysts that speed up chemical reactions. Proteins. They are substrate specific.

Catabolic reactions (enzymes)

Breaking down of a substance using enzymes

Anabolic reactions (enzymes)

combining of substances using enzymes

Factors affecting enzyme activity

Temperature, pH, enzyme concentration, substrate concentration

Enzyme inhibitors

substances that block some or all of the action of enzymes

Unicellular organisms

One cell, can survive on its own, obtains nutrients and gases through simple diffusion across surface

Hierarchical structure of organisms

Organelles make up cells which make up tissues which make up organs which make up systems which make up organisms

Autotroph

An organism that makes its own food (usually via photosynthesis)

Heterotroph

An organism that cannot make its own food and must consume it.

Stomates

Openings in leaves to exchange photosynthetic gases: water vapor, carbon dioxide, and oxygen

roots

Absorbs water and minerals from the soil. Anchors plants in the ground.

Xylem

Transports water and minerals from the roots up the plant

Phloem

Transports food up and down the plant.

gas exchange structures in fish

Oxygen diffuses into gills when water washes over them. At the same time, carbon dioxide diffuses out.

Gas exchange structures in amphibians

Uses the lungs, the lining of the mouth and the skin's surface for gas exchange

gas exchange structures in humans

Occurs in the alveoli of the lungs. Oxygen diffuses into the capillaries and binds to the haemoglobin of red blood cells. Carbon dioxide diffuses out of the capillary.

Physical digestion

Physically breaking down food into smaller pieces, occurs by chewing in the mouth and peristalsis of the stomach

Chemical digestion

Digestive enzymes break down food into absorbable molecules. Most chemical digestion occurs in the stomach and small intestine but the process starts in the mouth with the enzyme amylase from saliva which begins breaking down carbohydrates

Absorption

The process by which nutrient molecules pass through the wall of the digestive system into the blood to be transported around the body.

Components of blood

red blood cells, white blood cells, platelets, plasma

Open transport system

No heart or system of closed tubes. Haemolymph is used as the medium for transport.

closed transport system

No openings, consists of heart, arteries, capillaries and veins

Arteries

carry blood away from heart; oxygenated except for pulmonary circulation

Veins

Carry blood deoxygenated blood back to the heart. Oxygenated for pulmonary circulation.

Fossils

The preserved remains or traces of organisms that once lived on Earth.

Theory of natural selection

1. Survival of the fittest
2. Individuals will pass on genetic material to offspring
3. Individuals vary in terms of structure, behaviour and physiology

Adaptations

Features that allow organisms to survive and reproduce. they can be structural, behavioural and physiological.

Selection pressures

Any environmental change that affects individuals in a population. Individuals with variations that enable them to survive under changing conditions have a selective advantage.

Convergent evolution

Process by which unrelated organisms independently evolve similarities when adapting to similar environments

Divergent evolution

When two or more species sharing a common ancestor become more different over time

Evidence for evolution

Fossils, biogeography, comparative anatomy/embryology, biochemistry

Pangaea

The name of the single landmass that broke apart 200 million years ago and gave rise to today's continents.

Biodiversity

Variety of life

Keystone species

A species that influences the survival of many other species in an ecosystem

Niche

The role an organism plays within an ecosystem

Abundance

the number of individuals in a population

Distribution

The areas where the organism is found

Parasitism

A relationship between two organisms of different species where one benefits and the other is harmed

Mutualism

A relationship between two species in which both species benefit

Commensalism

A relationship between two organisms in which one organism benefits and the other is unaffected

Allelopathy

The production of chemicals by plants that inhibit the growth of neighbouring plants

Decomposer

Break down chemical energy of dead organic matter into simpler forms so it can be used as nutrients for other organisms. E.g. fungi and bacteria

Human impacts

Introduced species (cane toads), pollution, deforestation, land clearing, management of waterways, roadkill, overharvesting, global warming

Food web

A community of organisms where there are several interrelated food chains

Abiotic factors

Non-living components of environment. E.g. light, water pressure, humidity, oxygen availability, salinity

Biotic factors

living parts of an ecosystem e.g. plants, animals

Sclerophyll plants

Vegetation adapted to long periods of dryness and heat. They have adapted with hard leaves, leaves parallel to sunlight and short internodes

Prickly pear adaptations

Shallow roots, sharp spines, flattened leaves, thin stem

interspecific competition

competition between different species

intraspecific competition

competition between individuals of the same species

Cohesion

Attraction between molecules of the same substance

Adhesion

An attraction between molecules of different substances

Hypertonic solution

High concentration of solute compared to cell. Causes cell to shrivel

Hypotonic solution

Low concentration of solute compared to cell. Causes cell to burst.

Isotonic

Same concentration of solute in solution and cell

spongy mesophyll

loosely packed, irregularly shaped cells with spaces around them located below the palisade mesophyll. Wide gaps to facilitate gas exchange

palisade mesophyll

under the upper epidermis; high concentration of densely packed chloroplasts; where most photosynthesis takes place

Heart

A hollow, muscular organ that pumps blood throughout the body.

induced fit model

Change in the shape of an enzyme's active site that enhances the fit between the active site and its substrate(s)

lock and key model

The model of the enzyme that shows the substrate fitting perfectly into the active site. Less correct.

Transpiration cohesion tension theory

Explains how water flows up the xylem of plants. Involves, transpiration drawing water through the leaf from the stomata and cohesion & adhesion which help draw water up the xylem