b9

Question 1

habitat definition

Answer 1

the place where an organism lives

Question 2

population definition

Answer 2

all of the organisms in a given species, that live in the same habitat (at the same place)

Question 3

community definition

Answer 3

all the populations (of different species) that live together in a habitat

Question 4

ecosystem definition

Answer 4

interaction of a community of living organisms biotic with the abiotic parts of their environment

Question 5

biotic meaning

Answer 5

living

Question 6

abiotic meaning

Answer 6

non-living

Question 7

competition definition

Answer 7

interactions between organisms or species in which they both try to use the same limited resources

Question 8

interdependence definition

Answer 8

organisms in an ecosystem depending upon one another, with (complex) relationships between them all

Question 9

resources that animals compete for (4)

Answer 9

water
food
mates
territory

Question 10

resources that plants compete for (4)

Answer 10

water
mineral ions
space
light

Question 11

in a community there are rabbits, and snakes (which prey on the rabbits)

what happens to the population of rabbits when the population of snakes falls?

Answer 11

increases due to having less predators

Question 12

why can a factor be considered biotic

Answer 12

biotic because it is determined by living organisms

Question 13

why can a factor be considered abiotic

Answer 13

abiotic factor as it is not influenced by living organisms

Question 14

abundance definition

Answer 14

refers to how many organisms there are (in a given place)

Question 15

distribution definition

Answer 15

distribution refers to where the organisms are (in a given area)

Question 16

what is sampling

Answer 16

measure a subset of the organisms, and use that subset to make predictions about the whole population

Question 17

why is sampling used

Answer 17

in real life, measuring exactly how many organisms and where would be very time consuming and difficult

Question 18

what are the two main sampling methods

Answer 18

random quadrat sampling - to measure abundance
transects - to measure how distribution changes

Question 19

what is a quadrat

Answer 19

quare frames, divided into lots of smaller squares

Question 20

how would you use a quadrat

for example to measure the abundance of dandelions (in a 100x100m field using a 1x1m quadrat)

Answer 20

place tape measures along the length + width of the field (forming a large grid)

randomly generate x pairs of random coordinates

place quadrats at those coordinates and count how many dandelions are found in each quadrat.

calculate the mean number of dandelions per m^2.

estimate the total population size using our mean number of dandelions per m^2 and the total area of the field

Question 21

equation for total pop. size using quadrats

Answer 21

(area of field) x (avg. no. of organisms per m^2)

Question 22

how would you use transects to find the distribution of dandelions in a field stretching from lake to woodland

Answer 22

a transect line (tape measure) is laid out in a straight line between the lake and woodland

x quadrats are placed at regular intervals along the transect line

the abundance of dandelions is measured by counting the number of dandelions in each quadrat along the transect line, (from the lake to the woodland)

repeat this using new transect lines (parallel to the first).

Question 23

why measure data along multiple transect lines

Answer 23

so that the data gathered is more representative

Question 24

producer definition