Biology 1 Flashcards
What is an environment
An organism’s surroundings are its environment.
What can environmental factors do?
In all environments there are environmental factors that can change the organism, and non-living factors such as temperature or the amount of light.
What are the features of an organism
The features of an organism are its characteristics.
What are physical environmental factors?
Physical environmental factors are non-living factors.
What is variation?
The differences between the characteristics of organisms are known as variation.
What is environmental variation?
Environmental variation is variation caused by an organism’s environment.
What are some examples of environmental variation?
In humans, examples of environmental variation include scars and hairstyles.
Scars are made by
physical environmental factors, such as fire or sharp objects.
Hairstyles are caused by
Hairstyles follow fashion, which is an environmental factor caused by other people in your environment.
What is continuous variation?
Variation that can have any value between two points is continuous variation.
What is discontinuous variation?
Variation that can only have a value from a limited set of possible values is discontinuous variation.
What is classification
Classification is sorting organisms into groups.
What is a species?
A species is indeed the smallest group an organism can be classified into. A species is a group of organisms that share similar characteristics and can interbreed to produce fertile offspring. This means that individuals within a species can mate and create viable offspring that can also reproduce.
What do offspring get when they are born?
Offspring get a mixture of characteristics from their parents.
What is another way of saying “getting characteristics from their parents”?
We say they inherit these characteristics.
What is inherited variation?
inherited variation be characteristics which are inherited by their parents where it is transferred as a mixture between the two to its offspring.
Examples of inherited variation
Human eye colour, dimpled chins and blood groups.
Where are the instructions for inherited characteristics?
The instructions for inherited characteristics are stored in the genetic information found inside the nuclei of cells.
What happens in sexual reproduction?
In sexual reproduction, two gametes (one male and one female) fuse during fertilization to produce a zygote. Since the zygote contains genetic information from two parents, the offspring will have some characteristics of each parent.
What does every gamete contain?
Every gamete contains slightly different genetic information; no two gametes are identical.
Give an example of differences of gametes
For example, in people with dimpled chins, some of their gametes carry the instructions for a dimpled chin and some of their gametes may not. Since all gametes are different, brothers and sisters do not look exactly the same.
An example of discontinous inherited variation?
One example of discontinous inherited variation is blood group.
2 more examples of discontinous variation?
Having a dimpled chin and being able to roll your tongue.
Tell me 2 examples of contiuous inherited variation?
Human height and skin colour.
Explain how height variation can also be environmental
However, like many characteristics, these can also be affected by environmental factors. For example, tall parents are likely to produce tall children but children can only grow tall if they eat a healthy diet.
What do characteristics usually show when plotted on a histogram?
Characteristics that show continuous variation usually give a ‘bell shape’ when plotted on a bar chart. We can make this more obvious if we join the tops of the bars with a smooth curve.
What is the bell shape known as?
this shape is known as a normal distribution (and is the shape we often see in characteristics that show continuous variation)
What is statistics?
Statistics is collecting, analyzing and presenting data.
When do we use statistics:
Collect data (e.g using samples to estimate values)
Draw conclusions (e.g finding correlations using scatter graphs or calculating averages)
Present findings (e.g drawing graphs)
Make predictions
What is probability?
Probability is how likely something is going to happen
What did Watson and Crick do?
At lunchtime on 287 February 1653, two men burst into the eagle pub in Cambridge and one of them announced: ‘we have discovered the secret of life.’ Their names were James Watson and Francis Crick. They had just made a cardboard model of a substance called DNA.