B1 Topic 1 - Variation Flashcards
(25 cards)
What are the characteristics of plants?
They are Autotrophs (they make their own food)
They have chlorophyll
They are multicellular
Have cell walls
What are the characteristics of an Animal?
They are heterotrophs ( they have to move about to find things to eat)
They are multicellular
Don’t have cell walls
Don’t have chlorophyll
What are the characteristics of Fungi?
They are saprophytes (they feed off dead organisms)
Are multicellular
Have a cell wall
Don’t have chlorophyll
What are the characteristics of protoctists?
They are unicellular
They have a nucleus
What are the characteristics of prokaryotes?
They are unicellular
They don’t have a nucleus
What organism cannot be put into any kingdom?
Viruses because thy are non living
List the subdivisions of the kingdoms in order
Kingdom Phylum Class Order Family Genus Species
Animals in the phylum Chordata all have a what?
A supporting rod. The backbone
List the groups that’s vertebrates are divided into
Fish Amphibians Reptiles Birds Mammals
Name one vertebrate that doesn’t fit into one class
Duck billed platypus
What is the difference between oviparous and viviparous
Oviparous lays eggs whereas viviparous give birth to live young
What is genetic variation?
The mixing of genes from two parents
It can also occur due to mutations - changes in the organisms genes.
What is environmental variation?
Any difference that’s caused by the environment an organism lives in
Example:
1) a plant grow on a sunny windowsill would grow healthy and green.
2) but the same plant grown in darkness would grow tall and spindly and its leaves would turn yellow
Explain continuous variation
It is when the individuals in a population vary within a range
There are no separate groups E.g. Humans can be any height within a range
Explain discontinuous variation
It is when there are two or me separate groups
Each individual can only fall into one of these groups E.g. Humans can have a blood group A,B,AB or O
Explain how organisms in volcanic vents are adapted to high temperatures
Volcanic vents (hydrothermal vents) in the seabed send out hot water and minerals into the ocean
Bacteria live on chemicals from the vent
The the conditions are extremely hot and under high temperature so the organisms have adapted to cope with this
How does natural selection work?
- most organisms give birth to more young that will survive to become adults
- individuals have to compete with each other for resources
- individuals that have characteristics which better match the environment have a better chance of survival and being able to breed.
- these useful characteristics are more likely to be passed on to the next generation
- over time there will be more and more individuals with the better characteristics
What is the evidence to support evolution
DNA RESEARCH
1) evolution means all organisms are related
2) scientists found that there is evidence to support this E.g. Humans and chimps have very similar DNA, so are closely related
RESISTANT ORGANISMS
1) the poison warfarin was used to kill rats
2) but a certain gene gives rats resistance to warfarin
3) rats with the resistance have a better change of survival and breeding successfully
4) so now some rat populations are warfarin resistant
5) this is a real life example of natural selection
Most cells in your body have a …… Which contains …..
Nucleus
Chromosomes
The human cell nucleus contains how many pairs of chromosomes?
23 - there are two number 19 chromosomes, two number 12s, two number 3s etc
Chromosomes carry …. Which control …..
They carry genes and different genes control different characteristics e.g. Eye colour
There can be different versions of the same gene, called a ….
Allele
What is cystic fibrosis and what is it caused by?
It’s a genetic disorder caused by s recessive allele
It results in the body producing thick sticky mucus in the air passages, gut and pancreas
The symptoms include breathing problems, lung infections and fertility problems
People with only one copy of the allele (e.g. Ff) won’t have the disorder, they’re carriers
For a child to have a chance of inheriting the disorder, both parents must be carriers or sufferers (ff)
What is sickle cell anaemia
It is a genetic disorder where red blood cells are a funny shape
These blood cells can get stuck in capillaries (tiny blood vessels) so body cells don’t get enough oxygen.
Symptoms include painful joins and muscles, fever and tiredness
