Characteristics of Living Things 1 Identify the basic
Characteristics of Living Things 1. Identify the basic processes and characteristics common to all living organisms. 2. Recall that living things are composed of cells, tissues, organs and systems, and understand that growth results from cell division. THS Biology
Identify the basic processes and characteristics common to all living organisms: reproduction, nutrition, response, cells, respiration, adaptation, growth, movement, excretion, secretion, and regulation. Every single living organism carries out the same basic processes – different organisms just carry them out in different ways… THS Biology
The basic processes and characteristics common to all living organisms include: THS Biology
1 Reproduction 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. THS Biology
2 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). • Animals need to find an external source of food. THS Biology
Food Requirements • Autotrophs can make their own food. • Photoautotrophs use sunlight to make food (photosynthesis). • Chemoautotrophs use chemicals such as iron & sulfur as their energy. THS Biology
Food Requirements • Heterotrophs can NOT make their own food; they must consume other organisms: – Herbivores eat plants. – Carnivores eat meat. – Omnivores eat plants & animals. THS Biology
3 Respond to Environment Response means the ability of an organism to gather information and react to it • Some of the things that cause living organisms to respond are light, sound, touch, chemicals, gravity… – 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. THS Biology
Response to Stimuli Organisms respond to temperature, water, food supplies, etc. in order to survive & reproduce. THS Biology
4 Consist of 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 THS Biology muscle cells blood cells bone cells
Cells Have a Genetic Code • DNA (deoxyribose nucleic acid) carries the genetic code for all organisms. • All organisms contain DNA. • DNA codes for the proteins that make up cells & do all the work. THS Biology
Living things are composed of cells, tissues, organs and systems, and understand that growth results from cell division If living organisms are composed of cells, what do they need in order to grow bigger? … MORE CELLS !! THS Biology
Cell Division click to see a real cell dividing © A. Kihara (Hosei University) Cell division takes place in 3 stages: 1. A copy of the nucleus is made. 2. The cell membrane grows inwards to divide the cytoplasm. 3. The two new cells then separate…the new cells then grow to full size. THS Biology
Chemistry of Living Things atoms compounds/molecules inorganic compounds minerals carbohydrates starch THS Biology sugars proteins lipids made of amino acids fats & oils nucleic acids DNA RNA
5 Respiration means 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. THS Biology
6 Adaptation • Adaptation is the change in living organisms that allow them to live successfully in an environment. • Adaptations enable living organisms to cope with environmental stresses and pressures. • Adaptations can be structural, behavioral or physiological: – Structural adaptations are special body parts of an organism that help it to survive in its natural habitat (e. g. , skin color, shape, body covering). – Behavioral adaptations are special ways a particular organism behaves to survive in its natural habitat (e. g. , phototropism). – Physiological adaptations are systems present in an organism that allow it to perform certain biochemical reactions (e. g. , making venom, secreting slime, homeostasis). THS Biology
Evolution Transmission of characteristics, physical or mental from parents to offspring, that is from one generation to the successive generation. THS Biology
7 Growth & Development THS Biology
Growth & Development Growth means the organism develops into an adult • 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. THS Biology
Metabolism • The sum of all the chemical reactions in an organism. • Always requires energy. • Sunlight is the ultimate energy for life on Earth. THS Biology
Regulation • Homeostasis: the tendency toward a relatively stable equilibrium between interdependent elements. • The adaption of form or behavior of an organism to changed conditions: – Groups of organisms (not individual) change over time in order to survive within changing environment. – Fossil records show changes in groups of organisms. THS Biology
8 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. THS Biology
9 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. NH 3 THS Biology
10 Synthesis or Secretion • Collection of glands that secrete chemical messages we call hormones. • The process of elaborating a specific product as a result of the activity of a gland, this activity may range from separating a specific substance of the blood to the elaboration of a new chemical substance. THS Biology
Recall that living things are composed of cells, tissues, organs and systems, and understand that growth results from cell division 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 THS Biology
Recall that living things are composed of cells, tissues, organs and systems, and understand that growth results from cell division Organs • Tissues can be organized into groups to form organs, each organs with 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. THS Biology
Recall that living things are composed of cells, tissues, organs and systems, and understand that growth results from cell division 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… THS Biology
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? THS Biology
- Slides: 28