2. Evolution Pt1 Flashcards
What’s biological classification?
- it’s the process of sorting living things into groups according to their similarities
- it helps study them and see how closely they’re related in terms of evolution
Who devised taxa and what is it?
- it’s uses a hierarchical system designed by Carl Linnaeus in the 18th century
- by observing characteristics and grouping organism he devised 7 levels that all living things can be placed in
- modern biochemistry has challenged the Linnaean system
What are the 7 taxa?
- Kingdom
- Phylum
- Class
- Order
- Family
- Genus
- Species (individuals can breed to form fertile offspring)
What 2 taxa are mostly commonly used? Eg. Homo sapiens
Genus (capital first letter) Then species (all lower case)
What is Homo sapiens an example of?
A binomial name (2 names) (genus & species)
It should be in italics or underlined
Why is it important that the Latin binomial is used?
- they know what organism they’re referring to as they have different local names around the world
- using the Latin names also prevents any country from being offended their name wasn’t chosen
What is the modern classification system?
- the three-domain system was introduced in the 1970s by Carl Woese
- using modern analysis of DNA, ribosomes, RNA anaylsis and other biological molecules has produced a higher level of classification
- improved microscopes
What’s different between how we classified organism before and how we do it now?
- used to be based on observation (taxa)
- now it’s of the internal structurales of the organism (the three-domain system)
What are the three domains?
- Eukaryotae-cells with a nucleus (plant, animal, fungi, protoctist)
- Bacteria- Eubacteria, Cyanobacteria (true bacteria)
- Archae- Archaebacteria (primitive bacteria usually living in extreme environments)
These are then sub dived into the 7 taxa
what has the analysis of DNA helped with?
-more accurately grouping species together by their evolutionary relationships
What can you tell from evolutionary trees?
-the branches show at which point they started to evolve separately
-following the branches shows you the evolutionary distance between the species
-where they shared a common ancestor
(the common will be extinct but the descendants won’t)
Why is the phrase ‘man evolved from monkey’ wrong?
-we both evolved from a common ancestor which is now extinct
What are the 3 main types of adaptation?
- Structural- anatomy specialised in shape, size, colour
- Functional- biochemical process
- Behavioural (just animals)- actions carried out such as migration, using tools etc.
What are extremophiles? Give an example.
-Organisms that can survive and reproduce in the most difficult (extreme) conditions
-mostly microorganisms
-eg. High temperature, pressure or salt concentration
(Bacteria living in deep sea vents are extremophiles
Give an example of an extremophile that can survive high temperatures
- thermophiles
- they can survive high temperatures as their enzymes don’t denature
Explain how some extremophiles can survive very salty condition?
-some bacteria can survive very salty conditions by preventing water loss from their cytoplasm by osmosis
What are the 4 main functions of animal adaptations?
- Finding food
- Evading predators and Defences
- Survive the conditions
- Finding a mate
Explain some adaptations that help animals finding food?
- camouflage, to help sneak up on prey eg. Tigers, polar bears. Some change their camouflage with the seasons
- Sharpe teeth & claws for gripping and killing prey
- Good hearing & eyesight eyes at the front to judge distance to prey
- Appropriate teeth (sharper or flat) to chew food eg. Cows have flat teeth and all they eat is grass lions have sharks death to rip into its prey
Explain some adaptations that help animals evade from predators?
- camouflage to hide eg. White rabbits in snow
- strong muscles to run away quickly
- Defences such as shells, spikes or horns/antlers
- eyes on the side of there head to look out for predators
Explain some adaptations that help animals survive the cold?
- a thick layer of blubber (fat) under the sink for insulation
- fur/feathers for insulation
- small extremities eg. Ears, to reduce surface area
- animals living in cold conditions are often larger than others, this decreases their surface area to volume ratio which reduces heat loss
Explain some adaptations that help animals survive hot and dry climates?
- these animals are often (large SA: Volume ratio) to increase heat loss
- they have little body fat under the skin and thin fur to aid heat loss
- (elephants) they have thin ear to help the lose heat
- their kidneys are adapted to produce very concentrated urine, minimising water loss
- they will restrict their activity to the night when it’s cooler or burrow in the ground for shelter
Explain some adaptations that help animals find mates?
-colourful feathers, dancing, calls, scents, fighting off rivals can be used to attract a mate
Most plant adaptation are related to what?
Their ability to carry out photosynthesis
What are 4 aims of plant adaptations?
- Sunlight
- Collect water
- Reducing water loss
- Storing water
Explain some adaptations that help plants get more sunlight?
- grow tall to reach the light above surrounding plants eg. Vines
- board, flat leaves to capture as much light as possible
Explain some adaptations that help plants collect water?
- in dry climates plants have a very extensive root system
- roots that go deep collect water a long way down
- spread out, shallow roots collect water over a wide area after rainfall
Explain some adaptations that help plants reduce heat loss?
water is lost by transpiration through the stomatas plants minimise this by:
- reducing surface area which curls leaves possibly forming spikes. The curling traps a layer of moist air in the leaf to reducing evaporation. Spikes stop animals from it.
- thick, waxy cuticle prevents water from evaporating from the surface of the leaf (but if it’s too waxy it’ll become shiny and reflect light
- Broad leaves and hairs can collect dew and funnel it towards the roots
