cells Flashcards
an instrument for viewing small objects
microscope
the smallest unit of life. Cells are the building blocks of living things. There are many different sized and shaped cells in animals and plants, as well as single-celled organisms.
cells
instrument for viewing very small objects. A light microscope can magnify things up to 1500 times.
light microscopes
instrument for viewing very small objects. An electron microscope is much more powerful than a light microscope and can magnify things up to a million times.
electron microscopes
describes a microscope through which the specimen is seen using one eye only
monocular
a microscope with two eyepieces, so you use both eyes to look at the object
binocular
describes a microscope through which the specimen is viewed using both eyes
stereo
the number of times the image of an object has been enlarged using a lens or lens system. For example, a magnification of two means the object has been enlarged to twice its actual size.
magnification
describes an organism having only one cell
unicellular
having many cells. Most plants and animals are multicellular.
multi cellular
a length of one millionth of a metre
micrometre
a unit of measurement equal to one billionth of a metre
nanometre
a rapidly developing field that includes studying and investigating cells and other objects of the smallest dimensions
nanotechnology
organism classified as belonging to the Prokaryotae kingdom
Prokaryotae
member of the group of organisms that has a membrane around the nucleus in each of their cells
eukaryote
structure that encloses the contents of a cell and allows the movement of some materials in and out
cell- membrane
the fluid found inside cells
cytosol
small structures within a cell in which proteins such as enzymes are made
ribosomes
the jelly-like material inside a cell. It contains many organelles such as the nucleus and vacuoles.
cytoplasm
the chemical reactions occurring within an organism that enable the organism to use energy and grow and repair cells
metabolism
reproduction by the division of an organism (usually a single cell) into two new organisms
binary fission
the kingdom of organisms that have cells with a membrane around the nucleus, but no cell wall, large vacuole or chloroplasts
Animalia
the kingdom of organisms that have cells with a membrane around the nucleus, cell wall, large vacuole and chloroplasts, commonly called plants
Plantae
the kingdom of organisms, such as mushrooms and moulds, that help to decompose dead or decaying matter
fungi
the kingdom of organisms, including algae and protozoans, that do not fit into other groups
Protoctista
the kingdom of organisms that consist of single cells with a nucleus not surrounded by a membrane or a cell wall, commonly called bacteria
Prokaryotae
small rod-shaped organelles that supply energy to other parts of the cell. They are usually too small to be seen with light microscopes. Singular = mitochondrion
mitochondria
oval-shaped organelle found only in plant cells. Chloroplasts contain the pigment chlorophyll. They are the ‘factories’ in which carbon dioxide and water are changed by sunlight and water into food by the process of photosynthesis.
chloroplasts
the chemical reaction involving oxygen that moves the energy in glucose into the compound ATP. The body is able to use the energy contained in ATP
cellular respiration
the food-making process in plants that takes place in chloroplasts within cells. The process uses carbon dioxide, water and energy from the sun.
photosynthesis
the green-coloured chemical in plants that absorbs the light energy used in photosynthesis to make food from carbon dioxide and water
chlorophyll
type of tissue that transports sugars made in the leaves to other parts of a plant
phloem
transport of materials, such as water and glucose, in plants
translocation
pipelines for the flow of water up plants. They are made up of the remains of dead xylem cells fitted end to end with the joining walls broken down. Lignin in the cell walls gives them strength.
xylem vessels
a hard substance in the walls of dead xylem cells that make up the tubes carrying water up plant stems. Lignin forms up to 30 per cent of the wood of trees
lignin
small openings mainly on the lower surface of leaves. These pores are opened and closed by guard cells. Singular = stoma.
stomata
movement of water through a plant as a result of loss of water from the leaves
transpiration stream
groups of xylem and phloem vessels within plant stems
vascular bundles
loss of water from plant leaves through their stomata
transpiration
Plant stems and leaves wilt when there is insufficient water in their cells.
wilt
sacs within a cell used to store food and wastes. Plant cells usually have one large vacuole. Animal cells have several small vacuoles or none at all.
vacuoles
describes cells that are not firm due to loss of water
flaccid
describes something that is firm
turgid
a disease resulting in the uncontrolled growth of body cells, forming tumours
cancer
an abnormal growth
tumour
describes a tumour that does not spread to other parts of the body
benign
describes a type of tumour that damages cells and can spread to other parts of the body
malignant
