Classification and Evolution Flashcards
Module 4
What is classification and why is there a need for it?
It is the organisation of living things into groups based upon their similarities and differences.
Why do scientists generally classify organisms?
⭐ To identify species.
⭐ To predict characteristics.
⭐ To find evolutionary links.
How many taxonomic groups are there in the hierarchy of classification?
Seven (7) groups.
Give the 7 taxonomic groups in the hierarchy of classification.
Kingdom ➺ Phylum ➺ Class ➺ Order ➺ Family ➺ Genus ➺ Species.
What has recently been added to the classification system?
Domains.
What are the domains in the classification in the classification system?
There are 3 Domains:
❁ Eukaryota
❁ Archea
❁ Bacteria
What is the first section within the classification system?
Life.
State the definition of the term species.
A group of organisms that share particular characteristics that can interbreed to produce fertile offspring.
What are the criteria when naming organisms/nomenclature?
❁ Bi - two, Latin - universal.
❁ Genus then species is written.
❁ The name of the organism should be italised/underlined or capitalised - only for the Genus NOT the species.
Who devised the bionomial nomenclature?
It was devised by Carl Linneaus.
What were the disadvantages of the previous naming systems?
- They were descriptive and local, often based upon characteristics, and differed from one place to the next.
- Common names and appearance did not show the relationships.
Give an example of naming.
Homo sapiens. ➺ H. sapiens.
What is the mechanism that can be used to describe the idea of evolution.
Natural selection.
List the main contributions of Darwin and Wallace.
Both Darwin and Wallace had similar ideas and discovered the mechanism of natural selection for evolutionary change.
*However, Darwin carried out his work on the Galapagos Islands whilst Wallace carried out his work in Borneo/Indonesia. Wallace presented his ideas to Darwin who released this as a joint publication.
What are 4 important observations that were made by Darwin.
- No two organisms are identical.
- Offspring are genetically similar in appearance to their parents.
- Organisms produce a lot of offspring.
- Populations tend to stay stable in size.
What conclusions can be drawn from their theories?
Organism struggle to survive, and individuals with better adapted traits are more likely to survive and reproduce, passing on these characteristics. Over time/generations these characteristics will be more common and give rise to a newer species.
Give some reasons why people did not believe in Darwin’s theory.
What is variation?
It is the differences between organisms. OR. The name given to differences between individuals of the same species.
Do all organism show variation?
Yes, this even includes identical twins.
What is variation with a species known as?
Intraspecific variation.
What is variation between a species known as?
Interspecific variation.
List two causes of variation.
Genes/genetic and environmental factors.
Give some environmental factors that can affect plants.
Soil conditions, light intensity, nutrient and food availability, temperature, rainfall, pH.
What are some causes of genetic variation and explain these.
Alleles - can inherit different combinations.
Mutations - they can lead to changes in DNA, if they in a somatic (body) cell then it only affects the individuals but if it is present in gametes it can be inherited.
Meiosis - independent assortment and crossing over can lead to different combination.
Sexual reproduction - no two gametes are identical to each other and the offspring inherit half from each parent so they are not identical to either parent. Also, fertilisation is a random process.
List some examples of environmental variation.
Genes for a tall height but being malnourished so they do not reach their full height. Seasonal melanin production - e.g. flamingo turn pink when they eat shrimp.
What are two types of data.
Continuous and discontinuous data.
Describe continuous data.
It is generally a type of data which involves any numbers, such as height/mass. It can be represented using a line graph or histogram and the number of genes are influenced by environmental causes.
