1C1 Living things OB41 identify the basic processes and characteristics common to all living organisms: nutrition, respiration, excretion, growth, reproduction, movement and response OB42 recall that living things are composed of cells, tissues, organs and systems, and understand that growth results from cell division
Every single living organism carries out the same basic processes – different organisms just carry them out in different ways….
Characteristics of Life nutrition respiration excretion growth reproduction movement Sensitivity and
Nutrition means obtaining food All living organisms need food as a source of energy Plants can make their own food using energy from the sun (photosynthesis) – they are PRIMARY PRODUCERS Animals need to find an external source of food
Respiration means glucose cell oxygen releasing energy from food Glucose in the food is broken down inside cells, and energy is released Most organisms use oxygen for this process – so it is called aerobic respiration glucose oxygen cell energy water carbon dioxide
Excretion means the removal of toxic chemical substances toxic substances are poisonous and may harm cells if not removed examples of toxic substances are carbon dioxide and urea NH3
Growth means the organism develops into an adult all growth is by CELL DIVISION For micro-organisms, this means their cell grows to full size before reproducing For multi-celled organisms, this means that cells divide, organs grow in size, and systems develop maturity
Reproduction means producing more organisms of the species Scientists have a name for the “children” of all living organisms – they say OFFSPRING Reproduction means producing more organisms of the species Some organisms reproduce from one parent only – this is called ASEXUAL reproduction Other organisms reproduce by combining one cell from a male with one cell from a female – this is called SEXUAL reproduction
Movement means the ability of an organism to change position Some organisms can move the entire body eg single-celled organisms Some organisms can move part of the body eg plants Some organisms can move both their entire body, and each section of the body eg insects, amphibians, reptiles, mammals Most organisms move towards things they need and away from things that harm them
Sensitivity means the ability of an organism to gather information and respond to it (Response) Some of the things that cause living organisms to respond are light, sound, touch, chemicals, gravity…eg: Roots grow downwards in response to gravity, shoots grow towards light Both plants and animals use their sense of touch when climbing Predators use sound and smell to hunt for prey
Mrs Gren nutrition respiration excretion growth reproduction movement sensitivity and
Animal Cell
Plant Cell
Cells Animal Plant Nucleus Cell Membrane Vacuole Cell Wall Chloroplasts -contain Chlorophyll for photosynthesis
Parts of a Cell Nucleus-Controls the actions of the cell and carries instructions as DNA Cytoplasm-Jelly like substance that fills cell Membrane-Controls entrance and exit Vacuole-Storage
H/W Draw a cell with labels on a piece of paper the best ones go on the wall
Differences between Plant and Animal cells Plants have cell walls-to hold them up Plants have CHLOROPLASTS-to make energy by photosynthesis Plants have large vacuoles and animal cells have small vacuoles
Cells Some living things are composed of just a single cell eg bacteria Some living things are composed of a small number of simple and similar cells eg fungi Some living things are composed of very many cells, with many different structures and functions eg humans nerve cell muscle cells blood cells bone cells
Tissues Cells that have the same structure and function form tissues… Cells in tissues are usually joined together Animal tissues include muscle, bone and nerves for movement Plant tissues include xylem and phloem for transport phloem xylem
Organs Tissues can be organised into groups to form organs, each organ has a particular function Plant organs include the ROOT for absorbing water, LEAF for photosynthesis Animal organs include the HEART for pumping blood, LUNGS for gas exchange
Systems organs, tissues and cells can be organised into systems that carry out major functions in the organism eg: Reproductive system, Nervous system, Digestive System, Circulatory system…
If living organisms are composed of cells, what do they need in order to grow bigger? … …MORE CELLS !!
Cell division takes place in 3 stages… A copy of the nucleus is made © A. Kihara (Hosei University) click to see a real cell dividing Cell division takes place in 3 stages… A copy of the nucleus is made The cell membrane grows inwards to divide the cytoplasm The two new cells then separate …the new cells then grow to full size
What do you think? Most animals move about while most plants tend to “stay put” – why? Can you suggest one advantage and one disadvantage of being single-celled? Animals have highly developed nervous systems compared to plants – why? A lot of plants have to use the help or wind or insects for reproduction – why?
Living things The basic processes and characteristics common to all living organisms: nutrition, respiration, excretion, growth, reproduction, movement and response (MRS GREN) Recall that living things are composed of cells, tissues, organs and systems, and understand that growth results from cell division
H/W P 17,18 Q 2,3,5,9