5.6 Coping with climate change

Question 1

Changes attributed to climate change

Answer 1

1. Changing distribution of species

2. Altered development and life cycles

Question 2

Dominant species, Dominant organism

Answer 2

A
species which has an important effect on the
other organisms in a community. In many
British woods, for example, the dominant tree is
oak. Its size determines such factors as how
much light falls on the ground and the water
content of the soil. These factors determine the
other organisms able to grow in an oak wood.

Question 3

Parasite, Parasitic

Answer 3

An organism that lives in or
on a host organism. The parasite gains an
advantage from this relationship while the host
suffers a disadvantage. Parasites of humans
include malarial parasites and tapeworms,
bacteria such as those which cause food
poisoning, and viruses such the genital wart
virus. Witchweed is a parasitic weed that infects
crops such as maize in Africa.

Question 4

Temperature coefficient Q10

Answer 4

Q10= rate of reaction at temperature T +10 degrees/ rate of reaction at temperature T

most have a q10 between 2 and 3

Question 5

Optimum temperature

Answer 5

The temperature at
which the rate of an enzyme controlled reaction
is optimal; above or below the optimum
temperature the rate of reaction is lower. Below
the optimum temperature the enzyme and
substrate molecules have less kinetic energy,
they move more slowly and are less likely to
collide so the rate of reaction is lower. Above
the optimum temperature as a result of increased
vibration the enzyme starts to denature due to
the breaking of bonds within the enzyme
molecule.

Question 6

Denature

Answer 6

When a protein is denatured, the
chemical bonds that maintain its tertiary
structure are broken. As a result, the molecule
loses its shape and is unable to function. High
temperatures and changes in pH often lead to the
denaturing of proteins. This explains the effect
of high temperatures on the rate of enzymecatalysed
reactions.

Question 7

Phenology

Answer 7

The study of seasonal events in the

lives of organisms.

Question 8

Photoperiod

Answer 8

The light period during a day. In
temperate regions the amount of daylight varies
throughout the year. In the winter, it is light for a
relatively short part of the day. In the summer, it
is light for much longer. Photoperiod affects
many living organisms. It controls when birds
migrate, when plants flower, and when some
marine worms lay their eggs.