6 Markers Flashcards
Compare and contrast the structures of prokaryotic and eukaryotic cells (6 marks).
The genetic material in a eukaryotic cell is stored in the nucleus.
The genetic material in a prokaryotic cell is a single loop of DNA.
Both cells have a cell membrane.
Both cells have a cytoplasm.
Eukaryotic cells have mitochondria.
Prokaryotic cells have plasmids.
Describe the features of a stem cell and explain its importance (6 marks).
Stem cells are undifferentiated cells.
They can differentiate into various types of cells.
There are embryonic stem cells and adult stem cells.
They can divide indefinitely to produce more of the same stem cell.
Stem cells are important because they can be used to repair damaged cells because they can differentiate into those cells and then multiply.
Plants and animals have become adapted in many different ways to reduce the risk of being eaten by predators. Give examples of adaptations in animals and plants, stating whether these are structural, behavioural or functional.
A structural adaptation of plants is the formation of spines, found on plants such as cacti and roses.
A behavioural adaptation of plants is that they grow quickly towards the light to maximise photosynthesis.
A physiological adaptation of plants is the formation of poisons for defense.
A structural adaptation of animals is that prey often has eyes on the sides of their heads to easily spot predators.
A behavioural adaptation of animals is using tools. For example, crocodiles use twigs to lure birds, who would pick them up to build nests.
A physiological adaptation of animals is the production of venom. Many predators such as snakes and spiders produce venom both to defend themselves and kill their prey.
