ecosystems

Question 1

what is a population

Answer 1

a group of organisms of the same species living in the same area at the same time

Question 2

what is a community

Answer 2

all organisms of all the different species living in the same habitat

Question 3

what is a habitat

Answer 3

a particular area in which a population lives

Question 4

name the different types of ecosystems in malta

Answer 4

garigue
maquis
woodland
sand dunes
freshwater
rocky shores

Question 5

name a few characteristics of garigue ecosystems

Answer 5

-snap pockets of shallow soil
-high sun and heat exposure
-high wind exposure
-low water availability
-Maltese honey bee and blue rock thrush (animals)
-mediterranean thyme,heath and maltese pyramidal orchid (plants)

Question 6

name a few maquis characteristics

Answer 6

-deep soil
-more water availability, still limited
-relatively sheltered from wind
-hot and dry climate
- lentisk, bay laurel and fig tree (plants)
-maltese wall lizard, maltese rock centipede (animals)

Question 7

name the characteristics of woodland

Answer 7

-deep soils
-more water availability. still limited
-hot climate
-tall trees
-aleppo pine, Evergreen oak, Olive and carob trees (plants)
-european hedgehog, common black bird (animals)

Question 8

name some characteristics of sand dunes

Answer 8

-hot and dry climate
-dry sand
-rocks and wind
-high levels of salinity
- sand lizard, sand wasp (animals)
- sand couch, drop seed grass (plants)

Question 9

name a few characteristics of fresh water

Answer 9

-water temperature
-water PH
-oxygen concentration
-light
-great reed, Maltese waterwork (plants)
-painted frog, maltese freshwater crab (animals)

Question 10

name a few characteristics of rocky shores

Answer 10

-high winds
-many rock pools
-rough wave action and sea spray
-high levels of salinity
-maltese sea camomile, golden samphire (plants)
-flattened barnacle, black periwinkle (animals)

Question 11

what is an ecological niche

Answer 11

the way in which an organism interacts with other members of its community and the physical features of its surroundings

Question 12

name 3 types of local species

Answer 12

indigenous species
endemic species
alien species

Question 13

what is an indigenous species

Answer 13

a species that naturally occurs in that ecosystem
eg: carob tree found in malta and mediterranean

Question 14

what is an endemic species

Answer 14

a species which only occurs in one particular area of the world, said to be endemic to that region and doesn’t naturally occur anywhere else, making them vulnerable to extinction

Question 15

what are alien species

Answer 15

species that have been introduced to an ecosystem that they did not form part of before. These may cause disruptions in the ecosystems and may result in displacement of other species

Question 16

what is the carrying capacity

Answer 16

the maximum number of individuals if a species that can be supported by the rescources available in a given environment

Question 17

how can abiotic factors affect a community of organisms

Answer 17

-light intensity (more light more photosynthesis)
-temperature (affects photosynthesis )
- moisture levels (plants and animals need water to survive)
-wind intensity and direction (wind affects transpiration which affects photosynthesis)

Question 18

what are two important stimuli for plants

Answer 18

light and gravity

Question 19

what are auxins

Answer 19

hormones that cause plants to react in certain ways, produced at the tips of shoots and roots

Question 20

what is phototropism

Answer 20

a growth response to light

Question 21

what is geotropism

Answer 21

a growth response to gravity

Question 22

phototropism causes :

Answer 22

SHOOT move TOWARDS light
ROOT moves AWAY from light

Question 23

geotropism causes :

Answer 23

SHOOTS move AWAY from gravity
ROOTS move TOWARDS gravity

Question 24

what are the main biotic factors affecting communities

Answer 24

availability of food
new predators
competition
new pathogens/parasites

Question 25

what’s a parasite

Answer 25

an organism that derives its food from another organism called the host, whilst the host is still alive- harming it in the process

Question 26

what are the two types of parasites

Answer 26

endoparasites- inside host (tapeworms)
ectoparasites- host surface (mosquito)

Question 27

what is a mutualistic relationship and give an example

Answer 27

a relationship between two organisms that benefits both
eg: insect pollination (bees+flowers)

Question 28

what do plants usually compete for

Answer 28

-water
-minerals
-space
-light for photosynthesis

Question 29

what do animals usually compete for

Answer 29

-food to eat
-water to drink
-mates
-territory

Question 30

explain a predictor pray relationship

Answer 30

the number of predators increases when there is more prey
the number of pray reduces when there are more predators
the number of predators reduces when there is less prey

Question 31

what are scavengers and decomposers

Answer 31

-scavengers feed on dead parts of organisms and digest it, they help keep the environment clean and reduce chances of disease spread
-decomposers feed on waste material of organisms and on their dead bodies. They break complex materials into simple inorganic substances and make vital nutrients available to ecosystems