cells Flashcards
Nucleus
The Nucleus is the control center of the cell. It contains DNA in the form of chromosomes and controls what the cell does and when.
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.
Prokaryotes
Organism classified as belonging to the Prokaryotae kingdom
Eukaryote
Member of the group of organisms that has a membrane around the nucleus in each of their cells
Cell Membrane
Structure that encloses the contents of a cell and allows the movement of some materials in and out
Cytosol
The fluid found inside cells
Ribosomes
Small structures within a cell in which proteins such as enzymes are made
Cytoplasm
The jelly-like material inside a cell. It contains many organelles such as the nucleus and vacuoles.
Plantae
The kingdom of organisms that have cells with a membrane around the nucleus, cell wall, large vacuole and chloroplasts, commonly called plants
Mitochondria
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.
Chloroplasts
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.
Vacuole
A space or vesicle within the cytoplasm of a cell, enclosed by a membrane and typically containing fluid.
Multicellular
Having many cells. Most plants and animals are multicellular.
Unicellular
Describes an organism having only one cell
Photosynthesis
The food-making process in plants that takes place in chloroplasts within cells. The process uses carbon dioxide, water and energy from the sun.
Chlorophyll
The green-coloured chemical in plants that absorbs the light energy used in photosynthesis to make food from carbon dioxide and water
Organelle
Small shapes that can do certain jobs inside a cell
Phloem
Type of tissue that transports sugars made in the leaves to other parts of a plant
Translocation
Transport of materials, such as water and glucose, in plants
Xylem Vessels
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.
Lignin
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.
Stomata
Small openings mainly on the lower surface of leaves. These pores are opened and closed by guard cells. Singular = stoma.
Transpiration Stream
Movement of water through a plant as a result of loss of water from the leaves
Vascular Bundles
Groups of xylem and phloem vessels within plant stems
Transpiration
Loss of water from plant leaves through their stomata
Guard Cells
Cells on either side of a stoma that work together to control the opening and closing of the stoma
Wilt
Droop. Plant stems and leaves wilt when there is insufficient water in their cells.
Vacuoles
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.
Flaccid
Describes cells that are not firm due to loss of water
Turgid
Describes something that is firm
