Download ScienceYear7KnowledgeorganiserIntroductiontoBiology

King Charles I School Knowledge Organiser
SCIENCE Introduction to Biology autumn 1
Cells and life processes
All living things can: move, sense, reproduce, grow, respire,
excrete and need nutrients.
Animal cells usually have an irregular shape, and plant
cells usually have a regular shape.
Animal cells are made up of
 a cell membrane (selective barrier)
 a nucleus (containing DNA and controlling the cell)
 cytoplasm (jelly-like fluid where reactions take
place)
Plant cells also contain
 a cell wall (to support the cell - cellulose)
 a vacuole (containing cell sap and helping to keep
the cell firm)
 chloroplasts (where photosynthesis occurs)
Using Microscopes
Cells are very small and can only be seen using a microscope.
A light microscope uses a series of lenses to produce a
magnified image of an object:
total magnification = eyepiece lens magnification ×
objective lens magnification
To make a slide
Take a sample (e.g. of onion
cells), carefully place onto a
glass slide. Add some stain
(e.g. iodine) and place a
cover slip on top of your
slide. Place onto the
microscope stage a view
cells
Unicellular Organisms & Diffusion
Organisation
Humans are multicellular organisms. Some
organisms are only made up of a single cell e.g.
bacteria, yeast, amoeba. They have adaptations
that make them very well suited for life in their
environment.
They use diffusion to get nutrients into and out
of the cell. Diffusion is the movement of
particles form a high concentration to a low
concentration.
Cells can form tissues (e.g. muscle tissue), tissues
can form organs (e.g. heart), organs form organ
systems, and organ systems form organisms.
Organ systems include: circulatory system,
respiratory system, digestive system, nervous
system, reproductive system, leaf canopy
E.g. Digestive system is needed to supply nutrients
to the cells and breakdown food into these
nutrients. Organs include the oesophagus, stomach,
liver, small intestine, large intestine.
Specialised cells
Humans are multicellular. That means we are made of lots of cells, not just one cell.
Multicellular organisms need specialised organ systems to carry out a function.
They work together like a team to support the different processes in an organism.
E.g. Sperm cell (adapted to contain the male DNA and swim to the egg cell);
Ciliated cell (waft mucus); Red blood cell (haemoglobin for oxygen transport, large
surface area); Nerve cell (long, carries electrical impulses); Root hair cell (large
surface area, thin cell wall, no chloroplasts).
Classification
Animals are classified into
vertebrates (back bone) and
invertebrates (external skeleton).
The 5 vertebrate groups are
mammals (fur, milk, birth live young),
birds (feathers), reptiles (scale,
venom), amphibians (moist skin), fish
(gills). Some can be hard to classify
(e.g. penguin).
Keys help us identify organisms.
Habitats and Adaptations
Habitat - The place where an organism lives (e.g. pond,
woodland, savannah, rainforest). Changes can happen daily or
each season. Organisms need to be adapted to survive their
habitat (e.g. camouflaged, claws to catch prey).
Adaptations to hot – large surface area (e.g. large ears),
burrow in the day to keep cool
Adaptation to cold – thick fur, large paws
These adaptations can be behavioural (e.g. burrowing) and
physical (e.g. long neck). Adaptations increase the chance an
organism can survive and reproduce.