Biology yr 7 Flashcards
Living organisms have certain life processes in common. There are seven things that they need to do to count as being alive.
What does phrase MRS GREN stand for?
Movement - all living things move, even plants
Respiration - getting energy from food
Sensitivity - detecting changes in the surroundings
Growth - all living things grow
Reproduction - making more living things of the same type
Excretion - getting rid of waste
Nutrition - taking in and using food
Cells
Cells are the basic building blocks of all animals and plants. They are so small, you need to use a light microscope to see them.
Name the parts of a microscope and the how to use them.
- the object is placed on a rectangular glass slide
- the slide is placed on a stage with a light source below
- light shines through the object and into the objective lens
- the light passes through the eyepiece lens and from there into your eye
Animal cells and plant cells
Animal cells usually have an irregular shape, and plant cells usually have a regular shape. Cells are made up of different parts.
What are the parts that make up the cell and can you draw both cells?
Animal cells and plant cells both contain:
Cell membrane
Cytoplasm
Nucleus
Mitochondria
Plant cells also contain these parts, which are not found in animal cells:
Cell wall
Vacuole
Chloroplasts
What does a CELL MEMBRANE do?
Controls the movement of substances into and out of the cell.
Found in plants and animals.
What is Cytoplasm?
Jelly-like substance, where chemical reactions happen.
Found in plants and animals.
What does the Nucleus do?
Carries genetic information and controls what happens inside the cell.
Found in plants and animals.
Stop looking around and concentrate! :o)
What is Mitochondria?
Where most respiration reactions happen.
Animals and Plants
What is the Vacuole?
Contains a liquid called cell sap, which keeps the cell firm.
Plants only.
What is the Cell wall?
Made of a tough substance called cellulose, which supports the cell.
Plants only!
Cells and their functions
Humans are multicellular - we are made of lots of cells, not just one cell.
The cells in many multicellular animals and plants are specialised, so that they can share out the processes of life.
They work together like a team to support the different processes in an organism.
Name and drawer the Specialised Cells.
Epithelial Cell Leucocyte Liver Cell Fat Cell Cartilage Cell Striated Muscle Fibre Nerve Cell 1 Nerve Cell 2 Bone Cell Smooth Muscle Cell
List the Function and Special Features of the following special ANIMAL cells:
BLOOD CELL
Function: to carry OXYGEN
Features:
Large surface area, for oxygen to pass through.
Contains HAEMOGLOBIN which joins with oxygen.
Contains NO NUCLEUS.
NERVE CELLS
Function:
To carry nerve impulses to different parts of the body.
Features:
Long.
Connections at each end.
Carries electrical signals.
FEMALE REPRODUCTIVE CELL (Egg Cells)
Function:
To JOIN with male cell, and then to PROVIDE FOOD for the NEW CELL that’s been formed.
Features:
Large
Contains lot’s of CYTOPLASM
MALE REPRODUCTIVE CELL (Sperm Cell)
Function:
To reach female cell, and JOIN with it.
Features:
Long TAIL for swimming
HEAD for getting into the female cell
List the Function and Special Features of the following special PLANT cells:
ROOT HAIR CELL
Function:
To absorb WATER and MINERALS
Features:
Large Surface Area
LEAF CELL
Function:
To absorb sunlight for PHOTOSYNTHESIS
Features:
Large surface area
Lot’s of CHLOROPLASTS
UNICELLULAR ORGANISMS
A unicellular organism is a living thing that is just one cell.
Name the different types of unicellular organism.
BACTERIA
PROTOZOA
UNICELLULAR FUNGI
These organisms are NOT simple, in fact they can be very complex. They have adaptations that make them very well suited for life in their environment.
BACTERIA
Write a description of the cell characteristics and list it’s parts.
Bacteria are tiny. A typical bacterial cell is just a few micrometres across (a few thousandths of a millimetre).
The structure of a bacterial cell is different to an animal or plant cell. For example, they do not have a nucleus but they may have a flagellum. This is a tail-like part of the cell that can spin, moving the cell along.
Cell Parts: Chromosomal DNA Plasmid DNA Cell Membrane Cell Wall Flagellum (not always present)
PROTOZOA
Protozoa are unicellular organisms that live in water or in damp places.
The AMOEBA is an example of one. Although it is just one cell, it has adaptations that let it behave a bit like an animal.
What are these adaptations?
Produces PSEDOPODIA (“false feet”) that let it move about.
Its pseudopodia can surround food and take it inside the cell. (Like hands?? :oD)
CONTRACTILE VACUOLES appear inside the cell, then merge with the surface to remove waste. (Poops).
YEAST
Yeast are unicellular fungi.
They are used by brewers and wine-makers because they convert sugar into alcohol, and by bakers because they can produce carbon dioxide to make bread to rise.
Describe the YEAST CELL
Yeast have a cell wall, like plant cells, but NO CHLOROPLASTS.
This means they have to absorb sugars for their nutrition, rather than being able to make their own food by photosynthesis
Yeast can reproduce by producing a bud.
The bud grows until it is large enough to split from the parent cell as a new yeast cell.
CELLS, TISSUES, ORGANS and SYSTEMS
Multicellular organisms are organised into increasingly complex parts.
List in order, from least complex to most complex:
Cells Tissues Organs Organ systems Organism
TISSUES
Animal cells and plant cells can form tissues, such as muscle tissue in animals.
A living tissue is made from a GROUP OF CELLS WITH A SIMILAR STRUCTURE AND FUNCTION, which all work together to do a particular job.
List examples of tissues:
Muscle
The lining of the INTESTINE
The lining of the LUNGS
XYLEM (tubes that carry water in a plant)
ORGANS
An organ is made from a group of different tissues, which all work together to do a particular job.
List examples of organs:
Heart Lung Stomach Brain Leaf Root
ORGAN SYSTEMS
An organ system is made from a group of different organs, which all work together to do a particular job.
List examples of organ systems:
CIRCULATORY system RESPIRATORY system DIGESTIVE system NERVOUS system REPRODUCTIVE System
Cells are organised into tissues, organs, systems and organisms!
