Nature and Variety of Life Flashcards
Movement
The ability to change location or position (e.g. walking, plant tropisms)
Reproduction
The production of offspring (e.g. having children, dropping seeds)
Sensitivity
The ability to detect and respond to stimuli (e.g. goosebumps)
Homeostasis
The ability to maintain stable internal conditions (e.g. body temperature)
Growth
The development of an organism/increasing in mass or volume (e.g. growth)
Respiration
The release of energy in the cells from food
Excretion
Organisms ridding themselves of waste produced by chemical reactions in cells (e.g. urinating)
Nutrition
Where organisms acquire the materials needed to carry out all living processes (e.g. eating)
What are the life processes?
MRS H GREN Movement, Reproduction, Sensitivity, Homeostasis, Growth, Respiration, Excretion, Nutrition
Unicellular organism
A living thing composed of a single cell
Organism
An entire living thing that carries out all the basic functions of life
Multicellular organism
A living thing composed of multiple cells
Organ systems
A group of organs that work together to perform a function (e.g. digestive system)
Organ
Several tissues working together to perform a function
Tissue
A group of similar cells that perform the same function
Cell
The smallest unit of life, made up of organelles
Organelle
A tiny cell structure that carries out a specific function within the cell
Nucleus
Contains chromosomes carrying genetic material, controls which proteins are made
Cytoplasm
Where the chemical reactions take place in the cell
Cell surface membrane
Controls what enters and leaves the cell (is selectively permeable)
Chloroplast
Absorbs light energy to be used in photosynthesis in plants and algae
Vacuole
A membrane in the cell that contains cell sap, which stores dissolved sugars, mineral ions and other solutes
Cell wall
Gives plant cells structure, made of cellulose
Characteristics of plants
Multicellular, contain chloroplasts, autotrophic, have cellulose cell walls, store carbohydrates as starch (e.g. maize, beans)
Characteristics of animals
Multicellular, cannot photosynthesise, heterotrophic, no cell walls, have nervous coordination, store carbohydrates as glycogen (e.g. humans, mosquitos)
Characteristics of fungi
Unicellular or multicellular, cannot photosynthesise, heterotrophic/saprotrophic, cell walls made of chitin, store carbohydrates as glycogen, organised in hyphae which made a mycelium, can be pathogenic (e.g. mucor, yeast)
Protoctista
Unicellular, all have cell membranes cytoplasm and nucleus, some are heterotrophic while some are autotrophic with cellulose cell walls (e.g. plasmodium, chlorella, amoeba)
Bacteria
Unicellular, cell wall (made of polysaccharides and proteins) cell membrane and cytoplasm, has no nucleus but has a large circular chromosome surrounded by plasmids, some have a slime capsule, move using flagella, most are heterotrophic (but some are autotrophic) (e.g. lactobacillus bulgaricus)
Viruses
Small particles, made of genetic material surrounded by a protein coat, parasitic (can only reproduce inside living cells), pathogenic (e.g. HIV, influenza)
