Cells and kingdoms Flashcards
What is a pathogen?
A microorganism which causes infectious disease. They harm the host be releasing toxins or damaging cells. All viruses are pathogens, but bacteria, fungi and protoctist can also be pathogenic.
What do bacteria have instead of a nucleus?
A single circular chromosome.
What is a bacteria cell wall made off?
Peptidoglycan (a complex molecule of sugars and proteins)
Which kingdoms are multicellular and which are unicellular?
Multicellular: Plants, animals, many fungi.
Unicellular: Protoctist, bacteria, viruses
What do plant cells store carbohydrates as?
Starch or sucrose
Which cells store carbohydrates as glycogen?
Animals and fungi
What bacteria is a cause for pneumonia?
Pneumococcus
What is the size range for a bacteria cell?
1-5 micro metres
(compared to 20-50 micro metre animal cell.)
What does a virus consist of?
A strand of genetic material (a nucleic acid, either DNA or RNA) surrounded by a protein coat.
Is a virus alive?
No, does not respire or carry out any of the other normal processes which happen in living organisms.
How does a virus reproduce?
It has to enter a host cell:
1) They take over the ribosomes and enzymes to make new virus cells.
2) When many new viruses have been made, the cell dies and the viruses are released to infect new cells.
What is saprotrophic nutrition and what feeds with it?
Its when enzymes are secreted extracellularly to break down/digest food, then absorbing the digested molecules by diffusion.
Both fungi and some bacteria feed using this.
How do protoctist get energy?
Some photosynthesize, others feed on organic remains.
Give 3 examples of protoctist:
Amoeba: feed on other living organisms.
Chlorella: photosynthesize.
Plasmodium: causes malaria.
Give 3 examples of a virus:
Tobacco Mosaic Virus: causes brown patches on leaves by stopping chloroplast production.
Influenza: infects humans causing a cough and temperature ‘flu’
HIV virus: causes AIDS
