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.
multicellular
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
Prokaryotes
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
central part of an atom, made up of protons and neutrons. Also roundish structure inside a cell that acts as the control centre for the cell. Plural = nuclei.
nucleus
tiny, thread-like structure inside the nucleus of a cell. Chromosomes contain the DNA that carries genetic information.
chromosomes
the chemical substance found in all living things that encodes the genetic information of an organism
deoxyribonucleic acid (DNA)
cell division process that results in new cells with the same number of chromosomes as the original cell
mitosis
identical copy
clones
the process where the cytoplasm of a cell divides to form two daughter cells
cytokinesis
disease that can be transferred from one organism to another
infectious diseases
disease that cannot be transferred from one organism to another
non-infectious diseases
substance derived from a micro-organism and used to kill bacteria in the body
antibiotics
chemical used to kill bacteria on surfaces and non-living object
disinfectants
mild disinfectant used on body tissue to kill microbes
antiseptics
describes an antiseptic that kills bacteria
bactericidal
describes an antiseptic that stops bacteria from growing or dividing but doesn’t kill them
bacteriostatic
outermost layer of the skin
epidermis
the medical name for the deeper part of the skin
dermis
special cells that detect energy and convert it to electrical energy that is sent to the brain
receptors
tiny, coiled tube in the skin through which water and salt are removed from the body, helping to control body temperature
sweat glands
small opening in the skin. Perspiration reaches the surface of the skin through pores.
pores
change state from a liquid to a gas. Evaporation occurs only from the surface of a liquid.
evaporates
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
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
cells on either side of a stoma that work together to control the opening and closing of the stoma
guard cells
