Cell structure, Variety, Levels of Organisation Flashcards
Define the term respiration
The release of energy (production of ATP) from food
Define the term growth
A permanent increase in size; an increase in the total number of cells in an organism
Define the term homeostasis
The maintenance of a constant internal environment
Define the term reproduction
Producing offspring
Define the term sensitivity
An organism’s response to changes in its surroundings
Define the term excretion
The removal of waste products of metabolism from an organism (e.g. carbon dioxide, water(sweat), urea)
Give three examples of organelles
Mitochondria, chloroplasts, ribosomes, cytoplasm, cell membrane, cell wall, vacuole, nucleus etc.
State the function of the cytoplasm
Where chemical reactions take place; jelly-like substance in which organelles are suspended
State the function of the cell membrane
Controls the movement of substances into/out of the cell
State the function of the mitochondria
Site of aerobic respiration (release of energy; production of ATP)
State the function of chloroplasts
Contain chlorophyll, a green pigment, which absorbs light for photosynthesis (making glucose)
State the function of the cell wall
Maintains the rigidity/structure of a cell
State the function of ribosomes
Site of protein synthesis
State the function of the nucleus
Controls the cell; contains the instructions (DNA) needed to make new proteins
State the function of the vacuole
Contains cell sap and maintains/supports the shape of the cell
Give three examples of specialised cells
Red blood cells, white blood cells, root hair cells, liver cells etc.
Define the terms prokaryotic and eukaryotic, giving an example of each
Eukaryotes contain membrane-bound organelles (e.g. mitochondria, nucleus, chloroplasts) whereas prokaryotes do not. Eukaryotic kingdoms include animals, plants, fungi and protoctists; prokaryotes are bacteria
State three common characteristics between animals
Animals have nervous coordination (only kingdom that does), cannot carry out photosynthesis, do not have cell walls, can move from one place to another, store carbohydrates as glycogen
Give three differences between an animal cell and a bacterial cell
Animal cells have NO cell wall, they have a nucleus (bacteria have a single, twisted chromosome), mitochondria and larger ribosomes; bacteria have plasmids (extra loops of DNA)
Give three differences between an virus and a bacterial cell
Viruses have no cell membrane, no cell wall, no cytoplasm, no flagella, no plasmids and they cannot respire, feed, move etc.; viruses rely on a host cell to replicate themselves; viruses are smaller than bacteria
Define the term pathogen
An infective organism that causes disease
Give three structural differences between a plant cell and an animal cell
Plant cells have chloroplasts, a cellulose cell wall and a permanent vacuole. They also store carbohydrate as starch/sucrose as opposed to glycogen (animals)
Describe how fungi feed
By saprotrophic nutrition; they secrete extracellular enzymes from their thread-like hyphae and digest dead/decaying matter before reabsorbing the digested products
Give one example of a unicellular fungus and a multicellular fungus
Unicellular: yeast; multicellular: Mucor
True/False: Bacteria are always unicellular. Give two examples of bacteria
Lactobacillus (non-pathogenic; used to make yoghurt); Pneumococcus (pathogenic; causes pneumonia)
Give examples of two diseases caused by a virus
AIDS (caused by HIV); Flu (influenza); Ebola; Zika
Give the name of a virus that causes discoloration in plants meaning their leaves lose their green colour
Tobacco Mosaic Virus
State how animals, plants, fungi and bacteria all store carbohydrates
Animals, fungi and bacteria all store carbohydrates as GLYCOGEN; plants store carbohydrates as starch or sucrose
State how the composition of the cell wall is different in animals, plants, fungi and bacteria
Animals do NOT have a cell wall; plants (CELLULOSE); fungi (CHITIN); bacteria (MUREIN)
Give three examples of protoctists, including one which is a pathogen
Amoeba (animal cell-like); Chlorella (plant cell-like); Plasmodium (pathogenic; causes malaria)
Give the name of a bacterium used to make yoghurt
Lactobacillus
Describe the differences in DNA structure/organisation between animals, plants, bacteria, fungi and viruses
Animals, plants, fungi and protoctists all have a NUCLEUS (they are all eukaryotes so contain membrane-bound organelles); bacteria have a single twisted DNA chromosome; viruses have either DNA or RNA
True/False: Protoctists are always unicellular
TRUE
State the correct order of levels of organisation in an organism
Organelle, Cell, Tissue, Organ, Organ System
Define the term tissue
Many different cells working together to perform a function
Define the term organ
Many different tissues working together to perform a function
Give three examples of organ systems
Circulatory, excretory/urinary, digestive, nervous, endocrine, reproductive, respiratory etc
State a source of stem cells from which specialised cells originate
Bone marrow
