B1.1 Flashcards
What is classification?
Organising living organisms into groups
What are the 5 kingdoms living things are grouped into?
plants animals fungi protoctista prokaryote
Name some characteristics of plants
contain chlorophyll
autotrophs- make their own food by photosynthesis
rigid cell wall - supports cell
multicellular
Name some characteristics of animals
heterotrophs - eat other organisms
multicellular
no cell wall
no chloroplasts
Name some characteristics of fungi
Saprophytes - feed off dead organisms and matter
multicellular
cell wall
no chlorophyll
Name some characteristics of protoctista
unicellular - single celled
nucleus
e.g algae
Name some characteristics of prokaryote
unicellular
no nucleus
e.g bacteria
What are the differences between vertebrates and invertebrates?
vertebrates have a backbone and internal skeleton
Invertebrates don’t - some have external skeleton
What are the 5 groups vertebrates are divided into?
fish amphibians reptiles birds mammals
How are vertebrates divided into classes?
How they absorb oxygen:
lungs (e.g birds), gills (e.g fish), skin (e.g reptiles)
How they reproduce:
fertilisation occurs internally (e.g mammals) or externally (e.g fish)
oviparous- lay eggs (e.g reptiles), viviparous- give birth to live young and feed them milk (e.g mammals)
How they regulate body temperature:
homeotherms - warm blooded, use homeostasis (e.g mammals) poikilotherms - cold blooded , use environment (e.g reptiles)
What is the binomial system?
gives each species 2 part latin name
1st genus, 2nd species
e.g humans are homo sapiens
How does the binomial system help scientists?
enables them to: identify species study species conserve species target conservation efforts
What is a ring species?
A group of related populations living in neighbouring areas
Populations next to each other can interbreed and produce fertile offspring, populations further apart can’t
What are the 2 types of variation?
continuous and discontinous
What are the differences between the two types of variation?
continuous- individuals in a population vary within a range. no distinct categories (e.g human height, number of leaves on a tree)
discontinuous - two or more distinct categories, individuals only fall into one or the other (e.g human blood group, bacteria either antibiotic resistant or not)
What causes genetic variation?
characteristics determined by genes inherited from parents
most animals get genes from mother and father
mutations can also cause differences in characteristics of individuals
e.g eye colour, blood group, inherited disorders
What causes environmental variation?
environment organisms live and grow in can cause differences between members of same species
covers wide range of differences
e.g diet, exercise, temperature, light level, amount of water
What variation is caused by genes and the environment?
most characteristics determined by combination of both
e.g weight, height, skin colour
e.g maximum height a plant can grow determined by genes but environment determines how tall it actually grows
What is natural selection?
survival of the fittest
Theory by Charles Darwin to explain evolution
What is evolution?
the slow and continuous change of organisms from one generation to the next
How does natural selection work?
most organisms produce more young than will survive to adulthood, population don’t dramatically increase as organisms have to compete for limited resources e.g food, water, mates
those with useful characteristics better adapted so more likely to survive and reproduce- useful characteristics passed on
those with less useful characteristics less likely to survive and reproduce, less able to compete
eventually, higher proportion of organisms with useful characteristics for survival compared to poorly adapted
eventually, less useful characteristics may be lost
What evidence is there to support evolution?
theory suggests all organisms evolved from shared common ancestors
closely related species evolved into separate species more recently , should have more similar DNA
what scientists discovered with humans and chimps
Warfarin used to kill rats
certain gene gives them resistance to it, able to survive and reproduce- gene passed on
now rat populations that are warfarin-resistant
How do organisms adapt to living in the deep sea?
virtually no light- plants can’t photosynehsise so less food
fish can emit light from parts of body (e.g Angler fish. rod-shaped spine in face, gives out light and attracts prey)
often have huge mouths (e.g rat tail moves along seabed scooping up food particles)
huge eyes adapted to dark
long feelers to locate prey
How do organisms adapt to polar regions?
Polar Bears- Arctic
compact shape- small surface area, reduce heat loss
thick layer of blubber- insulation, acts as energy source when no food
thick coat- traps layer of air near skin for warmth
greasy fur- sheds water, prevents heat loss through evaporation
large feet- stops them sinking in the snow
Penguins- Antarctic
layer of insulating fat
oily feathers- shed water, reduce heat loss
huddle together - conserve heat
streamlined body - reduce water resistance, swim fast to catch fish
