cells Flashcards
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 objects
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
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
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 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
an instrument for viewing small objects
microscope
cells
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.
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
cells on either side of a stoma that work together to control the opening and closing of the stoma
guard cells
groups of xylem and phloem vessels within plant stems
vascular bundles
the 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
describes a type of tumour that damages cells and can spread to other parts of the body
malignant
