Biology Topic 1 - Cells and Organisms

Movement

ability to move a part or all of the organism

Respiration

chemical reaction to release energy

Sensitivity

the ability to react to an external stimulus

Homeostasis

the ability to regulate the organism’s internal conditions

Growth

the ability to grow and increase in size or mass

Reproduction

the ability to reproduce to make offspring

Excretion

the ability to release waste products

Nutrition

the ability to feed

Nucleus

where DNA is stored as chromosomes - controls activities of cells

Cell wall

freely permeable layer with rigid structure that supports and strengthens cell

Cell membrane

selectively permeable layer of lipid molecules that controls which substances can enter and leave the cell

Cytoplasm

fluid that is the location of many chemical reactions and anaerobic respiration

Mitochondria

where aerobic respiration occurs and most of the cell’s ATP is produced

Chloroplasts

where photosynthesis occurs and sugar is produced

Vacuole

contains cell sap - used for water storage and maintainance of turgor within the cell

Ribosomes

where amino acids are connected together to produce proteins

Plasmids

DNA molecules that contain genes that help cell to function

Organelle

structures within cells e.g. nucleus, chloroplast

Cell

unit that makes up a living organism

Tissue

collection of cells with similar structure and function e.g. muscle

Organ

collection of tissues that work together to perform a particular function e.g. brain, kidney

Organ System

several organs working together e.g. digestive, reproductive

Organism

a living thing that has all the functions of MRS H GREN

Eukaryote

complex cell that possesses a membrane-bound nucleus and organelles

Prokaryote

simple, single-celled organism that lacks a nucleus and membrane-bound organelles

Pathogen

microorganism that has the potential to cause disease

Plant

multicellular organism that contains chloroplasts and is able to carry out photosynthesis

Animal

multicellular organism that usually has nervous coordination and is able to move

Fungi

organisms that are unable to carry out photosynthesis and the body is usually organised into a mycelium. some are unicellular; others are not

Bacteria

microscopic single-celled organisms who can sometimes carry out photosynthesis but mostly feed off other organisms

Protoctists

microscopic single-celled organisms that can have the properties of animal or plant cells

Virus

smaller particles that are parasitic and can reproduce only inside living cells

Stem cells

unspecialised cells thata can divide many times by mitosis

Differentiation

the process by which stem cells become specialised - different genese are activated to make different cells

Embryonic stem cell

can differentiate into any specialised cell

Adult stem cell

can only different into certain cell types

Stem cell therapy

use of stem cells to repair damaged tissue to prevent disease