Section 2 b) Key Words

Cell Membrane: The semi-permeable membrane surrounding the cytoplasm of a cell

Cell Wall: A rigid, permeable layer of coating a cell that provides support etc. Made of chitin in fungi and cellulose in plants

Chloroplast: A chlorophyll-containing organelle that is used for photosynthesis. Found in plants and some bacteria and protoctists.

Cytoplasm: The main jelly-like substance of the cell, the medium in which chemical reactions take place.

Nucleus: The part of the cell containing the DNA "instructions"; it tells the cell what to do.

Vacuole: A store of water and minerals within plant cells and fungus cells. May be found as a small temporary organelle in animal cells.

Section 2 b) Summary

Cells are made up of different organelles and have different structures; those in the same kingdom will usually share the same basic characteristics, and their differences from other kingdoms is how we chose to classify them.

The table above shows the basic differences between plant and animal cells.

• The plant cell's more regular, rectangular shape is kept rigid by the cellulose cell walls, which provide the cells with support, and in turn support the plant as it doesn't have bones line animals do. 
• The plant cell also contains chloroplasts, which contain a green pigment called chlorophyll which converts carbon dioxide and water into oxygen and glucose with sunlight through photosynthesis. Photosynthesis is a process that allows the organism to create its own food. 
• Large sap vacuoles are found only in plant cells, animal cells may have a small temporary one, but this is not necessary to know. In plant cells, the vacuole is a large 'bag' filled with cell sap and helps to keep the cell turgid. 

Animal and plant cells also share similarities:

• Both have nucleuses or nuclei, which contain chromosomal DNA or 'genetic instructions' which tell the cell what to do: they give the cell its function.
• Both have a selectively-permeable cell membrane that controls what substances can pass through the cell.
• Both contain cytoplasm, the medium in which chemical reactions take place. It is controlled by enzymes. 

Section 2 b) Specification

2.2 describe cell structures, including the nucleus, cytoplasm, cell membrane, cell wall, chloroplast and vacuole
AND
2.3 describe the functions of the nucleus, cytoplasm, cell membrane, cell wall, chloroplast and vacuole 

The nucleus is, simply put, the "brain" of the cell. It contains DNA with instructions of what the cell should do and controls the cell.
Cytoplasm is the medium in which all of the chemical reactions within the cell take place.
The cell membrane is a thin, semi-permeable layer that holds the whole cell together.
The cell wall is not found in animal cells, but in plant cells it is made of cellulose and functions as support for the cell.
Chloroplasts contain chlorophyll, which is necessary for photosynthesis. They allow glucose to be created with just sunlight.
The vacuole contains water and stores of glucose and minerals, and supports the structure of the cells too.

2.4 compare the structures of plant and animal cells.

Animal and plant cells both have cytoplasm, nuclei, and cell membranes, however they are differently shaped and plant cells have additional structures, such as chloroplasts, cellulose cell walls and sap vacuoles. 

Section 2 a) Summary

Living organisms are made up of different levels of organisation, each categorised as follows:

Organelle: found within a cell, it helps the cell to carry out different functions, for example mitochondria respires and therefore provide the cell with energy, and a nucleus contains DNA within chromosomes that direct the cell's actions.

Cell: contains organelles, can be an organism on its own (uni-cellular) or part of a larger organism (multi-cellular). Makes up tissues. Can carry out a specific function, e.g. neurones, or nerve cells, transmit electrical impulses around the body, and in plants the palisade cell contains lots of chloroplasts for photosynthesis.

Tissue: made up of similar cells working together to carry out a specific function. Tissues make up organs and carry out vital roles, e.g. muscle tissue allows animals to move as it contracts and relaxes, connective tissues hold organs together and support them in place

Organ: Made up of a group of different tissues, found within organ systems. Carries out one or more specific function, e.g. the skin protects the body and regulates heat, the eyes pick up light that allows us to see

Organ system: a group of organs that work in a system to carry out life processes, e.g. circulatory system pumps blood around the body so oxygen can reach everywhere for respiration, nervous system transmits electrical impulses so the body can react to stimuli

Section 2 a) Key Words

Cell: "Building Block" of life, smallest structural and functional unit of an organism

Organ: A group of tissues working together to carry out 1 or more specific functions

Organelle: A structure within a cell that carries out a function

Organism: An entire living thing, it carries out the seven life processes

Organ System: A group of organs working to carry out specific life functions

Tissue: A group of cells working together to carry out a specific function

Section 2: Structures and Functions in Living Organisms Specification

a) Levels of organisation 

2.1 describe the levels of organisation within organisms: organelles, cells, tissues, organs and systems.


b) Cell structure

2.2 describe cell structures, including the nucleus, cytoplasm, cell membrane, cell wall, chloroplast and vacuole

2.3 describe the functions of the nucleus, cytoplasm, cell membrane, cell wall, chloroplast and vacuole 2.4 compare the structures of plant and animal cells.


c) Biological molecules

2.5 identify the chemical elements present in carbohydrates, proteins and lipids (fats and oils)

2.6 describe the structure of carbohydrates, proteins and lipids as large molecules made up from smaller basic units: starch and glycogen from simple sugar; protein from amino acids; lipid from fatty acids and glycerol

2.7 describe the tests for glucose and starch

2.8 understand the role of enzymes as biological catalysts in metabolic reactions

2.9 understand how the functioning of enzymes can be affected by changes in temperature, including changes due to change in active site

2.10 understand how the functioning of enzymes can be affected by changes in active site caused by changes in pH

2.11 describe experiments to investigate how enzyme activity can be affected by changes in temperature.


d) Movement of substances into and out of cells 

2.12 understand definitions of diffusion, osmosis and active transport

2.13 understand that movement of substances into and out of cells can be by diffusion, osmosis and active transport

2.14 understand the importance in plants of turgid cells as a means of support

2.15 understand the factors that affect the rate of movement of substances into and out of cells, to include the effects of surface area to volume ratio, temperature and concentration gradient

2.16 describe experiments to investigate diffusion and osmosis using living and non-living systems.


e) Nutrition

Flowering plants:
2.17 describe the process of photosynthesis and understand its importance in the conversion of light energy to chemical energy

2.18 write the word equation and the balanced chemical symbol equation for photosynthesis

2.19 understand how varying carbon dioxide concentration, light intensity and temperature affect the rate of photosynthesis

2.20 describe the structure of the leaf and explain how it is adapted for photosynthesis

2.21 understand that plants require mineral ions for growth and that magnesium ions are needed for chlorophyll and nitrate ions are needed for amino acids

2.22 describe experiments to investigate photosynthesis, showing the evolution of oxygen from a water plant, the production of starch and the requirements of light, carbon dioxide and chlorophyll

Humans:
2.23 understand that a balanced diet should include appropriate proportions of carbohydrate, protein, lipid, vitamins, minerals, water and dietary fibre

2.24 identify sources and describe functions of carbohydrate, protein, lipid (fats and oils), vitamins A, C and D, and the mineral ions calcium and iron, water and dietary fibre as components of the diet

2.25 understand that energy requirements vary with activity levels, age and pregnancy

2.26 describe the structures of the human alimentary canal and describe the functions of the mouth, oesophagus, stomach, small intestine, large intestine and pancreas

2.27 understand the processes of ingestion, digestion, absorption, assimilation and egestion

2.28 explain how and why food is moved through the gut by peristalsis

2.29 understand the role of digestive enzymes, to include the digestion of starch to glucose by amylase and maltase, the digestion of proteins to amino acids by proteases and the digestion of lipids to fatty acids and glycerol by lipases

2.30 understand that bile is produced by the liver and stored in the gall bladder, and understand the role of bile in neutralising stomach acid and emulsifying lipids

2.31 describe the structure of a villus and explain how this helps absorption of the products of digestion in the small intestine

2.32 describe an experiment to investigate the energy content in a food sample.


f) Respiration

2.33 understand that the process of respiration releases energy in living organisms

2.34 describe the differences between aerobic and anaerobic respiration

2.35 write the word equation and the balanced chemical symbol equation for aerobic respiration in living organisms

2.36 write the word equation for anaerobic respiration in plants and in animals

2.37 describe experiments to investigate the evolution of carbon dioxide and heat from respiring seeds or other suitable living organisms.


g) Gas exchange

2.38 understand the role of diffusion in gas exchange

Flowering plants:
2.39 understand gas exchange (of carbon dioxide and oxygen) in relation to respiration and photosynthesis

2.40 understand that respiration continues during the day and night, but that the net exchange of carbon dioxide and oxygen depends on the intensity of light

2.41 explain how the structure of the leaf is adapted for gas exchange

2.42 describe the role of stomata in gas exchange

2.43 describe experiments to investigate the effect of light on net gas exchange from a leaf, using hydrogen-carbonate indicator

Humans:
2.44 describe the structure of the thorax, including the ribs, intercostal muscles, diaphragm, trachea, bronchi, bronchioles, alveoli and pleural membranes

2.45 understand the role of the intercostal muscles and the diaphragm in ventilation

2.46 explain how alveoli are adapted for gas exchange by diffusion between air in the lungs and blood in capillaries

2.47 understand the biological consequences of smoking in relation to the lungs and the circulatory system, including coronary heart disease

2.48 describe experiments to investigate the effect of exercise on breathing in humans


h) Transport 

2.49 understand why simple, unicellular organisms can rely on diffusion for movement of substances in and out of the cell

2.50 understand the need for a transport system in multicellular organisms

Flowering plants:
2.51 describe the role of phloem in transporting sucrose and amino acids between the leaves and other parts of the plant

2.52 describe the role of xylem in transporting water and mineral salts from the roots to other parts of the plant

2.53 explain how water is absorbed by root hair cells

2.54 understand that transpiration is the evaporation of water from the surface of a plant

2.55 explain how the rate of transpiration is affected by changes in humidity, wind speed, temperature and light intensity

2.56 describe experiments to investigate the role of environmental factors in determining the rate of transpiration from a leafy shoot

Humans:
2.57 describe the composition of the blood: red blood cells, white blood cells, platelets and plasma

2.58 understand the role of plasma in the transport of carbon dioxide, digested food, urea, hormones and heat energy

2.59 explain how adaptations of red blood cells, including shape, structure and the presence of haemoglobin, make them suitable for the transport of oxygen

2.60 describe how the immune system responds to disease using white blood cells, illustrated by phagocytes ingesting pathogens and lymphocytes releasing antibodies specific to the pathogen

2.61 understand that vaccination results in the manufacture of memory cells, which enable future antibody production to the pathogen to occur sooner, faster and in greater quantity

2.62 understand that platelets are involved in blood clotting, which prevents blood loss and the entry of micro-organisms

2.63 describe the structure of the heart and how it functions

2.64 explain how the heart rate changes during exercise and under the influence of adrenaline

2.65 describe the structure of arteries, veins and capillaries and understand their roles

2.66 understand the general structure of the circulation system to include the blood vessels to and from the heart, the lungs, the liver and the kidneys.


i) Excretion

Flowering plants:
2.67 understand the origin of carbon dioxide and oxygen as waste products of metabolism and their loss from the stomata of a leaf

Humans:
2.68 recall that the lungs, kidneys and skin are organs of excretion

2.69 understand how the kidney carries out its roles of excretion and osmoregulation

2.70 describe the structure of the urinary system, including the kidneys, ureters, bladder and urethra

2.71 describe the structure of a nephron, to include Bowman’s capsule and glomerulus, convoluted tubules, loop of Henlé and collecting duct

2.72 describe ultrafiltration in the Bowman’s capsule and the composition of the glomerular filtrate

2.73 understand that water is reabsorbed into the blood from the collecting duct

2.74 understand that selective reabsorption of glucose occurs at the proximal convoluted tubule

2.75 describe the role of ADH in regulating the water content of the blood

2.76 understand that urine contains water, urea and salts.


j) Coordination and response

2.77 understand that organisms are able to respond to changes in their environment

2.78 understand that homeostasis is the maintenance of a constant internal environment and that body water content and body temperature are both examples of homeostasis

2.79 understand that a coordinated response requires a stimulus, a receptor and an effector

Flowering plants:
2.80 understand that plants respond to stimuli

2.81 describe the geotropic responses of roots and stems

2.82 describe positive phototropism of stems

Humans:
2.83 describe how responses can be controlled by nervous or by hormonal communication and understand the differences between the two systems

2.84 understand that the central nervous system consists of the brain and spinal cord and is linked to sense organs by nerves

2.85 understand that stimulation of receptors in the sense organs sends electrical impulses along nerves into and out of the central nervous system, resulting in rapid responses

2.86 describe the structure and functioning of a simple reflex arc illustrated by the withdrawal of a finger from a hot object

2.87 describe the structure and function of the eye as a receptor

2.88 understand the function of the eye in focusing near and distant objects, and in responding to changes in light intensity

2.89 describe the role of the skin in temperature regulation, with reference to sweating, vasoconstriction and vasodilation

2.90 understand the sources, roles and effects of the following hormones: ADH, adrenaline, insulin, testosterone, progesterone and oestrogen.

Section 2 a) Specification

2.1 describe the levels of organisation within organisms: organelles, cells, tissues, organs and systems.

Organelles are the specialised structures within a cell that carry out a specific function, e.g. the nucleus, vacuole, etc. They are the smallest level of organisation within an organism.

Cells are made up of organelles and are the smallest unit of life, the "building blocks", if you will, e.g. nerve cells, muscle cells, etc.

Tissues are made up of the lots of the same type of cell working together to carry out a specific function, e.g. palisade mesophyll, nervous tissue, etc.

Organs are groups of tissues working together to carry out a specific function in an organism, e.g. the brain, a leaf, etc.

Organ systems are a group of organs that work together to perform one or more functions, e.g. the nervous system, circulatory system, etc.

Organisms are entire living things that carry out the functions of MRS GREN, e.g. human, cactus

Section 1 b) Summary

Living organisms are organised into categories based on shared characteristics. The seven taxonomic groups of classification are:

• Kingdom (e.g. Animalia)
• Phylum (e.g. Chordata)
• Class (e.g. Mammalia)
• Order (e.g. Carnivora)
• Family (e.g. Canidae)
• Genus (e.g. Canis)
• Species (e.g. Lupus)

Species are internationally known by their binomial classification, which is a two-part latin name composed of species and genus used to identify groups of organisms that share similar characteristics and are able to breed to produce fertile offspring. In the above example, the species would be known as Canis Lupus (Grey Wolf). 

All living organisms fall under the five kingdoms of classification: Animals, plants, bacteria, fungi and protoctists. Each of these groups is defined by their own set of characteristics:

Animals
Multi-cellular, No cell walls, No chloroplasts = No photosynthesis, therefore they must consume other organisms to gain energy. Cells move freely.

Can move their entire body due to nervous system.
Glycogen - how animals store carbohydrates
Vertebrates are animals with spines/backbones
Invertebrates are animals without spines/backbones

Vertebrates can be split into the following categories:

• Mammals (warm-blooded, secrete milk, give birth to live young, have lungs, most have hair)
• Birds (warm-blooded, feathers, wings, beaks, hard shelled eggs, have lungs)
• Fish (cold-blooded, jelly-coated eggs laid in water, scales, fins and gills)
• Reptiles (cold-blooded, leathery-shelled eggs, scales, have lungs)
• Amphibians (cold-blooded, jelly-coated eggs laid in water, moist skin, gills when young, lungs when mature)

E.g. Cat, Dolphin, Owl, Chicken, Cod, Haddock, Adder, Blue-tongue Lizard, Salamander, Frog

Plants
Multi-cellular, Cellulose cell walls, Chloroplasts for photosynthesis, absorb water through their roots and up the xylem vessel by osmosis.

Move leaves etc. to face the sun
Starch or Sucrose - how plants store carbohydrates
Carnivorous plants: some plants adapt to nutrient-poor soil by attracting, trapping and digesting insects or small animals to gain nutrients from them.

E.g. Sunflower, Cacti, Oak, Yew, Palm

Bacteria
Uni-cellular, No Nucleus (Plasmid and DNA loop instead), Polysaccharide or Protein cell wall, some have Chloroplasts, all have Mesosomes

Some have flagellum for free movement
Glycogen or Lipid food stores

E.g. Lactobacillus Bulgaricus, Pneumococcus, Escherichia Coli (E.Coli), Salmonella

Fungi
Multi- or uni-cellular, Chitin cell walls, organised in fungal hyphal structures with threads/fibres called hyphae, which organise into mycelium.

Fungi feed through saprotrophic nutrition, also known as extracellular digestion. The cells secrete digestive enzymes to break down organic matter, which is then absorbed by the fungus.
Glycogen- how carbohydrates are stored in fungi

E.g. Yeast (uni-cellular), Mucor (multi-cellular)

Protoctists
Uni-cellular, characteristics vary: some resemble animal cells, some resemble plant cells, some are pathogenic

E.g. Amoeba, Plasmodium, Chlorella

Viruses are not classified as living organisms, they are a special case; they don't perform all seven life functions, and they can only reproduce inside a living cell. They are parasitic and pathogenic.

E.g. Human Immunodeficiency Virus (H.I.V), Influenza, Tobacco Mosaic Virus



Pathogens
A pathogen is a disease-causing particle or organism. It infects a living organism and inhibits their normal function. Pathogens can be viruses, bacteria, protoctists or fungi.

Section 1 b) Specification

1.2 describe the common features shared by organisms within the following main
groups: plants, animals, fungi, bacteria, protoctists and viruses, and for each
group describe examples and their features

The five kingdoms of classification are plants, animals, fungi, bacteria and protoctists. Viruses are not classified as living organisms, but they are a special case (they can carry out all of the functions of living organisms within a living cell)

Animals (Animalia) are multi-cellular organisms that need to feed off other living organisms as they do not contain chloroplasts for photosynthesis. Animal cells have no cell walls and are able to move freely. Animals are able to move their entire body due to their nervous system. They store carbohydrates as glycogen in their muscles.
Examples include: Humans, Fish, Bumble Bees, Chicken, Tortoises, etc.

Plants (Plantae) are multi-cellular organisms that contain chloroplasts to produce food through photosynthesis. They have cellulose cell walls, that provide the plant with structure and support, and they store carbohydrates as starch or sucrose. Carnivorous plants such as the venus flytrap are able to catch and digest small animals in order to obtain nutrients in poor soil.
Examples include: Rice, Sunflowers, Bananas, Beans, Roses, Wheat, etc.

Protoctists (Protoctista), also known as the 'dustbin kingdom', are a kingdom of greatly varied uni-cellular organisms. Some have characteristics of animal cells, some photosynthesize like plant cells, and some are pathogenic.
Examples include: Chlorella, Amoeba, Plasmodium, Euglena, Paramecium, etc.

Fungi (Fungus) can be multi- or uni-cellular. They cannot photosynthesize, so they must feed off other organisms. They do this through saprotrophic nutrition, the secretion of digestive enzymes into the surrounding environment to break down nutrients the fungus will then absorb the broken-down organic matter (this is also known as extracellular digestion, it happens outside the cell). Their bodies are organised in a fungal hyphal structure: they look like threads called 'hyphae', which are organised in mycelium. They have chitin cell walls and store carbohydrates as glycogen.
Examples include: Yeast (uni-cellular), Mucor, Basidiomycota, etc.

Bacteria (Prokaryotes) are uni-cellular organisms without a nucleus, instead containing a loop of DNA and a plasmid, which can move between cells. They have polysaccharide or protein cell walls, glycogen or lipid food stores and mesosomes for respiration. Some have flagellum to allow them to move, or chlorophyll to carry out photosynthesis (however most feed off other living organisms)
Examples include: Pneumococcus, Lactobacillus bulgaricus (used to make yoghurt), E.Coli, etc.

Viruses are much smaller than bacteria, and all are parasitic. They can only reproduce inside living cells, and don't carry out all of the seven life processes. Viruses are made up of genetic material and a protein coat. All viruses are pathogenic, disease-causing.
Examples include: Influenza, Human Immunodeficiency Virus (HIV), Tobacco Mosaic Virus, etc.

1.3 recall the term ‘pathogen’ and know that pathogens may be fungi, bacteria,
protoctists or viruses.

A pathogen is a disease-causing micro-organism. Pathogens include bacteria, viruses, fungi and protoctists.
Examples of pathogens:

• E.Coli (Bacterium)
• Influenza (Virus)
• Candida (Fungus)
• Pneumococcus (Bacterium)
• HIV (Virus)
• Cryptococcus (Fungus that causes meningitis)

Section 1 b) Key Words

Amphibians: Cold-blooded vertebrates that are semiterrestrial and oviparous. Their young are typically aqueous with gills.

Animals: A multicellular organism that feeds off other living organisms. Their cells have no cell walls, and they have a nervous system so they can move their whole bodies freely.

Bacteria: Unicellular organisms without nuclei, they have a loop of DNA and a plasmid instead. They have a cell wall and some contain chlorophyll for photosynthesis.

Birds: A class of warm-blooded oviparous veterbrates with feathers, a beak, and wings.

Binomial Classification: A internationally accepted two-part classification of species made up of genus and species.

Class: A taxonomic group between phylum and order

Classification: A way of grouping organisms based on their similarities. There are 7 levels of classification.

Family: A taxonomic group between genus and order

Fish: A cold-blooded oviparous class of animals that are vertebrates and have gills to breathe in water.

Fungi: Multi- or uni-cellular organisms, typically organised in fungal hyphal structures. They have chitin cell walls and secrete enzymes for extracellular saprotrophic nutrition

Genus: A taxonomic group between species and family

Invertebrates: Animals without a backbone

Kingdom: The highest taxonomic group - there are 5 kingdoms e.g. Animalia, plantae, protoctista

Mammals: A class of warm-blooded animals that are vertebrates and give birth to live young.

Multicellular: An organism made up of more than one cell

Order: A taxonomic group between class and family

Organisms: An individual living thing that carries out the seven life processes

Phylum: A taxonomic group between kingdom and class

Plants: Multicellular organism with chloroplasts for photosynthesis (produces its own food). They have cellulose cell walls and store carbohydrates as starch or sucrose.

Prokaryotes: Another name for the bacteria kingdom

Protoctists: Uni-cellular organisms that vary greatly in all other characteristics, they can be pathogenic (e.g. plasmodium which causes malaria) and can share characteristics with other kingdoms

Reptiles: A cold-blooded oviparous vertebrate that breathes through lungs and is covered in dry scales or plates

Species: A group of closely related organisms that are able to interbreed and produce live young. The fundamental category of taxonomic classification.

Unicellular: A single-celled organism

Vertebrates: Animals with a backbone

Viruses: Parasites that can only reproduce inside living cells. They are not classified as living organisms, they are a strand of genetic material surrounded by a protein coat.