Theme 4 : Chapter 11 - Stars and the Galaxy in Universe

STARS AND THE GALAXY IN UNIVERSE 

Structure Of The Sun :

 ▷ sun has 3 layers :
Ⅰ. Corona
Ⅱ. Chromosphere
Ⅲ. Photosphere 

» corona and chromosphere can only be         seen during the solar eclipse 

 » however, the layer that we can see clearly everyday from the earth is the photosphere











 THE SUN ECLIPSE

follow the video to understand more :

THE AURORA PHENOMENON

VARIOUS TYPES OF STARS

1. Neutron Star
2. White Dwaft
3. The Sun
4. Giant Star
5. Super Giant Star

TEMPERATURE AND COLOUR OF STARS

 

 LIFE CYCLE OF A STARS :

Constellation
≫ a group of stars arranged in specific pattern
≫ in the past, constellation were used to :
                                                                   a) a compass to show direction
                                                                   b) calender

examples of constellation :

 

Ecosystem : Interection Between Living Organism

INTERACTION BETWEEN LIVING ORGANISM

1) PREY-PREDATOR
2) COMPETITION
3) SYMBIOSIS

PREY-PREDATOR
- a relationship where an animal captures and eat another animals
                      examples: owl → rat
                                     tiger → goat/deer
                                     frog  → insect

 COMPETITION
- relationship where organisms compete with each other for food, light, water, shelter, mate or minerals

examples: compete for food

                 compete for light

- there are two type of competition :
                                                     i) Intra specific competition
                                                     ⅱ) Inter specific competition

SYMBIOSIS
-Three type of symbiosis : 
                                         ⅰ. commensalism
                                         ⅱ. mutualism
                                         ⅲ. parasitism 

Commensalism : - Relationship between two organisms. 
                                - The commensal benefit from the host
example :

                                                           tree and bird's nest fern.

Mutualism : - interaction that benefits both organisms
example : 

flower and bee

 Parasitism : - interaction that benefits the parasites
                        - host is harmed by the parasites

                                                                 mosquito and human

BIOLOGICAL CONTROL
» a method of using living things to kill the pests 
» use prey-predator relationship

Ladybird and the Aphids
-ladybird eat the aphids that can save the plant
-aphids (insect) can destroy the plant

Advantages of using biological control :
⋟ does not pollute the environment
⋟ does not kill other pests because natural enemies are used
⋟ cheap and safe to used