The nature and variety of living organisms

Question 1

MRS GRENC

Answer 1

Movement
Respiration
Sensibility - respond to surroundings
Growth
Reproduction
Excretion
Nutrition
Control their internal environment - homeostasis

Question 2

6 characteristics of prokaryotes

Answer 2

Oldest cell type
Small and simple
Lack nucleus
Lack organelles
Single-celled
Single circular chromosome

Question 3

6 characteristics of eukaryotes

Answer 3

evolved from prokaryotes
larger and more complex
contain nucleus
contains organelles
single-celled or multi-cellular
multiple linear chromosomes

Question 4

4 characteristics of both prokaryotes and eukaryotes

Answer 4

have DNA
have ribosomes
have cytoplasm
have plasma membrane

Question 5

Description of plants:

Answer 5

Eukaryotic
Plants are multicellular
They have chloroplasts which means they can photosynthesise
Their cells have cell walls, which are made of cellulose
Plants store carbohydrates as sucrose or starch
- Flowering plants like: cereals (e.g. maize) and herbaceous legumes (e.g. peas and beans)

Question 6

Description of animals

Answer 6

Eukaryotic
Animals are multicellular
They don’t have chloroplasts - don’t photosynthesise
Their cells don’t have cell walls
Most have some kind of nervous coordination - this means they can respond rapidly to changes in their environment
They can usually move around from one place to another
They often store carbohydrates in the form of glycogen
- Mammals (e.g. humans) and insects (e.g. houseflies and mosquitoes)

Question 7

Description of fungi

Answer 7

Some are single-celled
Others have a body called mycelium, which is made up of hyphae (thread-like structures) The hyphae contain a lot of nuclei.
They can’t photosynthesise
Their cells have cell walls made of chitin
Most feed by saprotrophic nutrition - they secrete extracellular enzymes into the area outside their body to dissolve their food, so they can then absorb the nutrients,
They can store carbohydrates as glycogen
- Yeast - this is a single - celled fungus
- Mucor - this is multicellular and has a mycelium and hyphae

Question 8

Description of protoctists

Answer 8

These are single-celled and microscopic
Some have chloroplasts and are similar to plant cells
Others are more like animal cells
- Chlorella (plant-cell like)
- Amoeba (animal-cell like) - lives in pond water

Question 9

Description of bacteria - 5

Answer 9

These are also single-celled and microscopic
They don’t have a nucleus
They have a circular chromosome of DNA
Some can photosynthesis
Most bacteria feed off other organisms - both living and dead
-Lactobacillus bulgaricus - can be used to make milk go sour and turn into yogurt. Its rod-shaped
Pneumococcus - spherical in shape

Question 10

Viruses

Answer 10

These are particles, rather than cells, and are smaller than bacteria
They can only reproduce inside living cells. A virus is an example of a parasite - it depends on other organisms to grow and reproduce
They infect all types of living organisms
They come in loads of different shapes and sizes
They don’t have a cellular structure - they have a protein coat around some genetic material (either DNA or RNA)
Influenza virus
Tobacco mosaic virus - this makes the leaves of tobacco plants discolored by stopping them from producing chloroplasts
HIV