Variation Flashcards
What is variation?
Variation involves small changes between organisms which may allow that organism to compete better for survival. Variation can have environmental or genetic causes.
What is continuous variation?
This is where characteristics are spread over a range of values, so there is a full range of “in-betweens”.
What is discontinuous variation?
This is where there are no intermediates, but rather distinctly different groups.
What is adaptation?
This is the characteristics or an organism that enables it to survive in its environment.
What characteristics does a polar bear need to survive in the Arctic?
- A white appearance - to camouflage against the white snow and also from prey.
- Thick layers of fat and fur - for insulation against the cold.
- A small survive area to volume ratio - to minimise heat loss.
- A greasy coat - to shed when swimming.
What characteristics does the desert fox have to survive?
- Large ears that loose heat - to help cool it
- Light-coloured fur - reflects the heat and camouflages it.
What characteristics do Arctic plants have to survive in the Arctic?
- They grow close to the ground and have small leaves - helps conserve water and avoid damage by the wind.
How did the Pompeii worm adapt to the high temperatures and pressures of the hydrothermal vents?
- Uses a thick layer of bacteria to protect it from heat
- Hides inside a papery tube to protect it from predators.
What examples are there of continuous variation?
- Height
- Weight
- Foot-length
What examples are there of discontinuous variation?
- Gender
- Blood group
- Eye colour
What causes are there of variation?
- Inherited causes of variation
- Environmental causes of variation
What are the inherited causes of variation?
Variation in a characteristic that is a result of genetic inheritance from the parents is called inherited variation. Each egg cell and each sperm cell contains half of the genetic information needed for an individual. When these join at fertilisation a new cell is formed with all the genetic information needed for an individual.
What are the examples of inherited variation?
- Eye colour
- Hair colour
- Skin colour
- Lobed or lobeless ears.
What are the environmental causes of variation?
Variation caused by the surroundings is called environmental variation. Characteristics of animal and plant species can be affected by factors such as climate, diet, accidents, culture and lifestyle. A plant in the shade of a big tree will will grow taller as it tries to reach more light.
What are the examples of environmental variation?
- Language and religion
- Flower colour in hydrangeas - these plants produce blue flowers in acidic soil and pink flowers in alkaline soil.
