B1 Lesson 3 Classification & Biodiversity Why do we need to preserve

biodiversity?
8B1 – Year 8 Biology 1 B1 Lesson 6 & 7 Ecology & Sampling
What are the 5 kingdoms? Describe the link between
size of group and Organisms depend on each How do you measure abundance?
Animals (e.g. tiger), fungi (e.g. yeast), plants, (e.g. other. This is called
daffodil), protoctists (e.g. amoeba) and characteristics. B1 Lesson 10, 11, 12 Variation You could measure abundance, e.g. population size, by taking a
The smaller the group, the interdependence. If one sample. You take a sample because it is not always possible to count
prokaryotes (e.g. bacteria). organism goes extinct (dies What is environmental variation?
more similar the every single organism from the population. A sample is an estimate.
characteristics of the out) then it will affect other Differences between organisms caused by their environment. Examples of this type of variation in humans are scars and hairstyles.
You can use a quadrat to sample a small area within a larger habitat.
What do we mean by a ‘scientific name’? organisms are. organisms, and they may The calculation you would do is:
A scientific name is made from a genus name and a species name. These are the names become extinct too. There are What is inherited variation? What is continuous and discontinuous variation?
of the last two groups. A scientific name is in Latin. They are in Latin so that everyone also many undiscovered Differences between organisms caused by DNA and genes. Continuous variation means that it can be any number from a Population size =
uses the same name for the same organism. This way, people don’t get confused! substances in organisms that Inherited variation happens because in sexual reproduction a wide range. Height is an example of continuous variation. Number of organisms in sample x total size of area
could be useful e.g. for sperm cell and an egg cell join together in fertilisation. This means Discontinuous variation means it can only be grouped into area of sample
What are some examples of scientific names? What is biodiversity? medicines. Higher biodiversity the offspring produced contains 50% DNA from the mother and specific categories. Flavours of crisp is an example of this type
Panthera tigris – tiger. Biodiversity is the range of different also means an area can 50% DNA from the father. of variation.
Panthera leo – lion. species of organisms in an area. recover quicker from a What does the accuracy of your sample depend on?
disaster.
1. The sample size – a large sample size means the estimate will be
well. B1 Lesson 1 Plant and Animal Cells B1 Lesson 8 & 9 DNA more accurate
B1 Lesson 2 Specialised Cells Who were the 4 scientists involved in
What is an organelle? discovering the structure of DNA? 2. How easy it is to record data – if it is easy to find organisms then
What is a specialised cell?
well. the estimate will be more accurate
An organelle is a structure inside a cell with a specific function. An example of an organelle is a ribosome which creates James Watson, Francis Crick, Maurice
A specialised cell has a specific function (job). Specialised cells have specific features
proteins in both plant and animal cells Wilkins and Rosalind Franklin
(adaptations) that make them suited to their job. Examples of specialised cells: muscle 3. Distribution – the estimate will be more accurate if the organisms
cell, ciliated epithelial cell, root hair cell, leaf palisade cell, red blood cell. are spread out evenly and randomly (and not all clumped together
Draw and label an animal cell Draw and label a plant cell Where is DNA found in a cell?
As chromosomes, in the nucleus in one place)
How are ciliated epithelial cells specialised?
These cells are found in the trachea and have tiny hairs called cilia which sweep mucus How many chromosomes in a cell?
and the trapped bacteria in it out of the lungs. This type of cell is also found in fallopian 46 in all body cells (23 pairs). There are
tubes (oviducts) where they waft from side to side to move the egg cell along the 23 chromosomes in sperm and egg
oviduct. cells .46 is the diploid number, 23 is the
haploid number.
How is the small intestine adapted?
The cells that line the small intestine absorb small food molecules produced by What are the main steps in extracting
digestion. These cells are adapted by having membranes with many tiny folds (called DNA?
microvilli). This increases the surface area of the cell for faster absorption of digested 1. Mash the substance containing DNA
food. e.g. peas, strawberries
2. Add salty water and detergent
3. Mash gently to mix
What is a gamete? 4. Filter the mixture
A gamete is a cell used for sexual reproduction. In animals, the males gametes are 5. Add cold ethanol slowly
sperm cells and the female gametes are egg cells. In plants, female gametes are ovules 6. Collect DNA
and male gametes are pollen grains. B1 Lesson 13 Natural Selection
What does the salty water do?
Clumps the DNA together What is natural selection?
How is a human egg cell specialised? When certain characteristics become more common in a population
An egg cell is surrounded by a jelly coat. After fertilisation by a sperm cell the cell What does the detergent do? because they give the organisms a survival advantage and so are passed
membrane and jelly coat become hard to stop other sperm cells entering. The Breaks down cell membranes and the on to the next generation. When this happens over time, this is called
cytoplasm is packed with nutrients to supply the fertilised egg with energy and raw
B1 Lesson 4 & 5 Adaptations of Plants and Animals membrane around the nucleus evolution.
materials. What adaptations do animals have, and how are these useful? Surface area:
Characteristic Function B1 Lesson 14 Transfers in Food Describe the process of natural selection.
Animals which are small, e.g. mice, have a 1. There is a population of organisms, e.g. moths, with different
Fish have gills This lets them absorb oxygen under water
large surface area. This means they will lose Chains characteristics (variation)
heat more quickly. Animals which are large, What do the arrows in a food chain mean? 2. There is a change in the environment e.g. air becomes more polluted
e.g. elephants, have a small surface area. This They show the direction of energy transfer. 3. Some of the organisms are better suited to this new environment
Fish have fins This lets them move through the water
means they lose heat less quickly. Some because they have more useful characteristics e.g. black moths are
Animals have This keeps them warm if the environment is cold, by animals have small ears or large ears for the What is a pyramid of number? more camouflaged against dark buildings
same reason e.g. a desert hare has large ears A way of visually showing the numbers of 4. These organisms with useful characteristics survive and reproduce
fur reducing the heat energy lost from their body
so that their large surface area means it can organism at each stage of a food chain. See e.g. black moths are not eaten by birds
Camouflage The organism can blend into its surroundings, making diagrams B and C below. 5. Over time, this characteristic becomes more common in the
lose heat from its body quickly, and keep cool
them less visible to predators and prey in the hot environment. population e.g. black moths become more common than peppered
How might energy be lost in a food chain? moths
How are sperm cells specialised for reproduction? Energy is lost as heat through respiration, in
What adaptations do plants have, and how are these useful? urine and faeces. Which two scientists developed the theory of evolution?
1. Plants have roots which are spread out and branched. Their roots have root hair cells. This gives plants a large surface area Charles Darwin and Alfred Russel Wallace
to absorb water quickly.

2. Xylem vessels are tubes found in the stem, roots and leaves of plants. These tubes are made from hollow, dead xylem cells. B1 Lesson 15 Toxic Poisons in Food Chains
These tubes are useful as they carry water and mineral ions. What is a pesticide?
A pesticide is a poison which kills pests (organisms which cause
3. Leaf palisade cells contain lots of chloroplasts. They are found at the top of a leaf. The chloroplasts absorb lots of light for problems).
photosynthesis.
Why are pesticides dangerous?
4. Underneath leaves are little holes called stomata. They are opened and closed by guard cells. Stomata open during the day Pesticides are dangerous because they can kill organisms they are not
to let carbon dioxide diffuse in and water vapour & oxygen out. They shut at night because no photosynthesis happens when intended for. The poisons are not broken down (they are persistent)
it is dark, so no carbon dioxide is needed. so they are passed along food chains.

5. Leaves are thin. This means carbon dioxide and water do not have to diffuse very far.
 Epithelial cell: A cell found on the surfaces of parts of the body.
Key Vocabulary Definitions
Eukaryotic: A cell with a nucleus is eukaryotic. Organisms that have cells like this are also said to be eukaryotic.
Abundance: how many of something there are
Fertilisation: Fusing of a male gamete with a female gamete.
Acrosome: A small vesicle in the tip of the head of a sperm cell which contains enzymes.
Flagellum: A tail-like structure that rotates, allowing a cell to move. Plural is flagella.
Adaptation: The features that something has to enable it to do a certain job or survive in a particular place.
Food chain: Shows which organisms eat other organisms in a habitat. Shows the direction energy moves through
Adapted: If something has adaptations for a certain function (job), it is said to be adapted to that function. the food chain.
Aerobic respiration: A type of respiration in which oxygen is used to release energy from glucose. Happens in the Food web: Many food chains linked together.
mitochondria. Gamete: A cell used for sexual reproduction.
Biodiversity: The range of different species of organisms in an area. Habitat: The place where an organism lives e.g. woodland
Catalyst: A substance that speeds up the rate of a reaction, without itself being used up. Haploid: Describes a cell that has one set of chromosomes.
Cell (surface) membrane: The membrane that controls what goes into and out of a cell. Inherited variation: Differences between organisms caused by DNA, which are passed on to offspring by their
Cell sap: Liquid found in the permanent vacuole in a plant cell. parents.
Cell wall: A tough layer of material around some cells, which is used for support. It is made of cellulose in plant cells. Interdependence: When organisms depend on each other for survival e.g. for food, shelter.
Bacteria have a flexible cell wall. Mitochondrion: A sub-cellular structure (organelle) in the cytoplasm of eukaryotic cells, where aerobic
Chlorophyll: The green pigment found inside chloroplasts. It absorbs light energy. respiration occurs to release energy. Plural is mitochondria.
Chloroplasts: A green disc containing chlorophyll, found in plant cells. Chloroplasts are where the plant makes Natural selection: A process where organisms that are better adapted to an environment will survive and
glucose, in photosynthesis. reproduce
Chromosome: A structure found in the nuclei of cells. Each chromosome contains one enormously long DNA Nucleus: Controls the cell. Contains DNA.
molecule. Organism: A living thing
Ciliated epithelial cell: A cell that lines certain tubes in the body, such as the trachea, and has cilia on its surface. Oviduct: A tube that carries egg cells from the ovaries to the uterus in females. Fertilisation happens here. It is
Cilia: Small hair-like structures on the surface of some cells. also called the fallopian tube.
Classification: A way of organising organisms into groups based on their similarities. Pesticide: A chemical which kills pests.
Continuous: Data values that can be any number within a wide range e.g. height Population: The number of organisms of a species found in a particular area.
Continuous variation: When variation in a characteristic can be measured as any value within a wide range e.g. arm Predator: An animal that catches and eats other animals.
length Producer: An organism capable of producing its own food e.g. green plants
Cytoplasm: The watery jelly inside a cell where the cell’s chemical reactions take place. Prey: An animal that is caught and eaten by another animal.
Digestion: A process that breaks large, insoluble molecules into smaller, more soluble substances. Quadrat: A square frame used to sample a particular area.
Diploid: Describes a cell that has two sets of chromosomes. Ribosome: Tiny sub-cellular structure that makes proteins.
Discontinuous: Data values that can only be a few options from a limited number of categories e.g. days of the week Sampling: The process of collecting some data from some of a population in order to draw conclusions about the
Discontinuous variation: When variation in a characteristic can only be categorised into specific groups e.g. fur whole population.
colour Semi-permeable: Describes something that will allow certain particles to pass through it but not others.
DNA: A substance that contains genetic information. Short for deoxyribonucleic acid. Specialised cell: A cell that is adapted for a certain specific function (job).
Egg cell: The female gamete (sex cell). Sperm cell: The male gamete (sex cell).
Embryo: The tiny new life that grows by cell division from a fertilised egg cell (zygote). Surface area: The total area of all the body surface which is exposed to the environment.
Endangered: When a species of organism is at risk of dying out. Vacuole: A storage space in cells which contains cell sap. Plant cells have a large, permanent vacuole that helps to
Environmental variation: Differences between organisms caused by environmental factors keep them rigid and maintain their shape.
Enzyme: A protein that can speed up some reactions in living things (e.g. breaking down molecules). It is a catalyst. Variation: Differences between organisms