section 1 - the nature and variety of organisms Flashcards
characteristics of living organisms
- NUTRITION
- RESPIRATION
- EXCRETION
- RESPONSE (to their surroundings)
- MOVEMENT
- HOMEOSTASIS (control of their internal conditions
- REPRODUCTION
- GROWTH
levels of organisation
organelles –> cells –> tissues –> organs –> organ systems —> organism
embryonic cells are not…
specialised
embryonic cells become specialised by …
cell differentiation - the process in which a cell changes to become specialised for its job
embryonic cells are also known as
stem cells - undifferentiated cells
adults have stem cells where?
in bone marrow
in bone marrow they can only become
blood cells eg treating leukemia
stem cell research is a moral issue, why?
some people disagree because embryos are used - potential for human life
some people agree because of the quality of existing life
What are the two types of cells called?
Eukaryotes and prokaryotes
What are eukaryotic cells?
- they are found in plants, animals, fungi and protoctists
- are 10-100 micrometers in size
What are prokaryotic cells?
- bacteria are prokaryotes
- 0.1-0.5 micrometers in size
What is a eukaryote?
An organism made up of eukaryotic cells
What features do a prokaryotic cell contain?
- plasmids (small rings of DNA that can replicate and move between cells to share genetic information)
What features do prokaryotic cells NOT contain?
- no mitochondria
- no chloroplasts
- no nucleus
Animals cells contain…?
- a nucleus
- a cell membrane
- a cytoplasm
- mitochondria
- ribosomes
What organelles do a plant cell contain?
- nucleus, cell membrane, cytoplasm, mitochondria, ribosomes
-chloroplasts, cell wall and vacuole
Are plants unicellular or multicellular?
Multicellular
How do plants store carbohydrates?
As sucrose or starch
What are a plant’s cell wall made up of?
Cellulose
Plants use what to photosynthesise?
Chloroplasts
Name TWO examples of a flowering plant
- cereals (eg maize)
- herbaceous legumes (eg peas and beans)
Are animals unicellular?
No obvs not idiot
U might be if u answered it wrong tho
(They’re multicellular)
What do animals not have that plants do?
- no chloroplasts, no cell walls (and no vacuole)
Give two examples of animal ‘groups’
- mammals (like humans)
- insects (like houseflies)
How do animals store carbohydrates?
As glycogen
What do animals have that means they can respond rapidly to changes within their environment?
Nervous coordination
Are fungi unicellular?
- trick question - some are, but others have a body called a MYCELIUM
What is the mycelium made up of?
Hyphae, which are THREAD-LIKE structures
What does hyphae contain?
Lots of nuclei
Can fungi photosynthesis
NO.
What are a fungi’s cell wall made up of?
Chitin
Fungi feed by what method?
Saprotrophic nutrition
Describe saprotrophic nutrition
Secrete extracellular enzymes into the area to dissolve the food and then they can absorb the nutrients
Fungi store carbohydrates as…?
Glycogen (like animals)
Is yeast a plant, fungi or a protoctist?
A fungi
Give 2 examples of a fungi
- yeast (single celled)
- mucor- multicellular and has a mycelium (and hyphae)
Are protocists eukaryotic or prokaryotic?
Eukaryotic (unlike bacteria)
Are protocists multicellular?
NO - unicellular
Do protocists contain chloroplasts?
Some do and are similar to PLANT cells. Others are more similar to animal cells
Two examples of a protoctist are..?
- chlorella (plant cell like)
- amoeba (animal cell like)
Do protoctists have a nucleus?
Yes
Give two examples of bacteria
- lactobacillus bulgaricus
- pneumococcus
What is the shape of a lactobacillus bulgaricus?
It is rod shaped
What is the use of a lactobacillus bulgaricus bacteria?
Can make milk go sour and become yogurt
What is the shape of a pneumococcus?
Spherical (round) in shape
Are bacteria single celled/unicellular?
Yes and microscopic
Can bacteria photosynthesis?
Some can
Do bacteria have a nucleus?
No
What does bacteria have instead of a nucleus?
Bacteria has a circular chromosome of DNA, as well as plasmids
What feeds off of other organisms (living and dead)?
Bacteria
Give two examples of human viruses
- influenza virus
- HIV
Give one example of a plant virus
- The tobacco mosaic virus
- discolours plants by preventing the production of chloroplasts
Viruses are NOT cells, what are they instead?
PARTICLES
Viruses only reproduce within where?
Living cells because a virus is a type of parasite
Give the definition of a parasite
An organism that depends on another organism to grow and reproduce
Viruses infect what types of living organisms
- ALL types
Are viruses one size?
No- have multiple shapes and sizes
Viruses have a p—————— c——— around genetic material instead of a ce—————— st———————
Fill in the gaps
- protein coat
- cellular structure
What is the virus’ genetic material
DNA or RNA
Pathogens are..?
Microorganism that are disease causing- for example, fungi, protoctistss, bacteria AND viruses
Are viruses living organisms?
Why/why not?
No (because they cannot reproduce on their own and are not made up of cells)
Give three examples of pathogens
- plasmodium, a PROTOCTIST, which causes malaria
- pneumococcus, BACTERIUM, which causes pneumonia
- influenza virus and HIV- VIRUSES
Give two types of insects
Houseflies, mosquitoes