Chapter 03 - Characteristics of Organisms Flashcards
(23 cards)
What are the common characteristics of a living organism?
Cellular organization
Nutrition
Respiration
Irritability and Co-ordination
Excretion
Movement
Reproduction
Growth and development
Describe the development of the embryo of human
Egg + Sperm => Embryo ===> Cell division ====> Multicellular organism
What is called nutrition?
The process by which the energy and the materials are obtained for the maintenance of life.
Energy is needed for the cell growth and to repair
the worn out structures. This energy is obtained by nutrients.
What are the two types of autotropism?
Photoautotropism, Chemoautotropism
Photoautotropism - using light energy
Chemoautotropism - using chemical reaction ex. bacteria
What is called respiration?
The process by which the stored food is transformed into energy inside the cells
What is called a stimulus and a response?
- A change which is strong enough to bring about a response is known as a stimulus.
- The reactions according to the changes in the environment are known as responses.
What is called Irritability and Co-ordination?
- The ability to respond to stimuli receives from internal or an external environment is known as irritability.
- The communication between different organs during responding to a stimulus is known as co-ordination
What is called Excretion?
Removal of the waste products from the body that are produced during metabolism.
Waste products are removed as Sweat ( Water, Salt ),** Exhaled gas** (* CO2, H2O* ) or Urine ( urea, water, salt)
Which organ of the body does nitrogenous excretion?
Kidney
What are the structures used by unicellular organisms for locomotion?
Cilia, Flagella, Pseudopodia
What are the structures used by muticellular organisms for locomotion?
Fins, Wings, Legs
What is reproduction?
Production of a new generation by a unicellular or a multicellular organism for the continuation of their species
They are sexual and asexual reproduction. During sexual reproduction, gametes of two individuals sperm and an egg of the same species unite to form a zygote. The first cell of the process of producing a new organism is the zygote.
During asexual reproduction, a single organism can produce an identical new offspring without the contribution of another organism.
What is the meaning of Growth and development?
- The growth of a unicellular organism is considered as the increase of the size and the volume of the cell.
- The cell growth means the irreversible increase of dry mass of the cell.
Accordingly, growth and development can be expressed in three steps.
1. Irreversible increase in size of the cell
2. Increase in number of cells by cell division
3. Cell differentiation
What is the device used to show the growth of a plant?
Auxanometer
How small are viruses compared to bacteria?
Viruses are about 1/1000th the size of bacteria and can only be seen with an electron microscope.
Are viruses considered cells?
NO
What are viruses composed of?
Viruses are made of nucleic acid (DNA or RNA) enclosed in a protein capsid.
What types of nucleic acids can viruses have?
Viruses may have either DNA or RNA as their genetic material.
Do viruses have organelles for metabolic reactions?
No
When does a virus become active
A virus becomes active only inside a host cell.
Do viruses show living or non-living characteristics?
Viruses show both living and non-living features depending on their status.
Name two plant diseases caused by viruses.
Banana bunchy top disease and curly leaf of chilies.
Name some animal viral diseases.
Influenza, common cold, Dengue, and AIDS.
