Variation And Evolution Flashcards
What is variation?
Within a species there is variation. Variations are differences in characteristics.
Describe what a characteristic is.
A feature of a species.
Explain the differences between environmental and inherited variation.
Environmental- variation caused by conditions that living organisms live and grow in.
Inherited- All living organisms characteristics are determined by the genes inherited from their parents.
Give 3 resources animals and plants compete for.
-mates: to continue their species
-nutrience
-food: to help them survive
-habitat
-territory
-water
What is the difference between continuous and discontinuous variation?
Continuous variations are species variations which you can measure and is a number in a range such as mass,height or handspan.
Discontinuous variations are species variations which are placed in to categories such as tongue rolling and non tongue rolling.
What is DNA?
DNA is the chemical that all genetic material in a cell is made up from.
What is a chromosome?
A chromosome is a structure found inside the nucleus of the cell- containing DNA and protein, organised into genes. (each cell has 23 pairs of chromosomes)
Explain how plants are adapted for their environment.
The giant amazon water lily- traps beetles with perfume, showers with pollen and looses colour and closes so beetle doesn’t come back
It has broad wings to get as much shnlight as it can
What is a gene?
A long strand of DNA arranged in a sequence one after the other in the nucleus of a cell
Describe factors that may effect extinction
- climate change
- cloning
Describe the extinction of a dodo.
deforestation, hunting, and destruction of their nests by animals brought to the island by the Dutch.
How are characteristics inherited?
When the egg is fertilised by sperm it makes a baby who inherits the genetic material from their parents.
The ovum and the sperm have the DNA instructions for making a human.
Describe the purpose of gene banks
Gene banks are where a collection of tissue cultures, seeds, plants or animals are preserved to create genetic diversity
Explain the process of selective breeding
To transfer a gene responsible for a desired characteristic from one organism into another organism so that it also has the desired characteristic. This is done by choosing parents with particular characteristics to breed together and produce offspring with more desirable characteristics..
Disadvantage: It may lead to a lack of variety in plant and animal species
What are the comparisons between selective breeding and cloning?
Selective Breeding
- Uses natural genetic variation.
- Breeds individuals with desired traits over generations.
- Doesn’t directly manipulate genes.
Cloning
- Produces exact genetic copies.
- Doesn’t rely on natural variation.
- Involves directly replicating genetic material.
In essence, selective breeding works with what nature provides, while cloning duplicates existing genetic material.
One example where selective breeding has been used
Selective breeding is commonly used in farming to improve meat yields in cows by pairing those with desirable traits, like large size, and after doing this for several years the farmer will have cows with high meat yield.
What is cloning plant
Cloning is where a plant cells are put into growth medium with hormones and grow into new clones of their parents.
Explain how animals can be adapted to cold environments
smaller ears for less heat loss
padded feet to help walk on snow
great sense of smell
larger surface area
smaller eyes to prevent going blind
white colour to reflect sun
fur
Explain how animals can be adapted to hot environments
not a lot of fat
thinner fur
fur camouflages with surroundings
smaller
longer legs to keep their bellies cool
larger ears
larger eyes
What is animal cloning
Farmers use cloned offsprings from their best bull and cow using embryo transplants. Sperm cells are taken from prize bull. Egg cells are taken from prize cow.
How are twins made
one fertilised egg (ovum) splits and develops into two babies with exactly the same genetic information
