1 Read the passage below. Use the information in the passage and your own
knowledge to answer the questions that follow.
Bees are insects that are important for the pollination of flowers of many
plants. Bees are attracted to flowers to collect a sweet substance called
nectar. After collecting nectar they return to their nest. Some of the nectar
is used to make honey. Humans keep bees in small homes called hives and
5 collect some of the honey. The bees live in a group called a colony inside the
hive and they do not mate as individual pairs like most insects.
Each bee colony consists of a single fertile queen bee and her many infertile
female offspring called worker bees. The colony also contains her male
offspring called drones.
10 Under normal circumstances the fertile queen bee will fly out of the hive to
mate with a number of drones from different hives. The queen takes the risk
of mating in this way so that her offspring have extra genetic variation that
may help to combat disease. The sperm are stored in the queen’s body and
released a few at a time as the eggs are laid. Some of the eggs may be
15 fertilised by the sperm and some may not be fertilised. Fertilised eggs
develop into worker bees with diploid body cells. Unfertilised eggs develop
into drones.
The body cells of the fertile queen bee contain 32 chromosomes. The sperm
cells produced by a single drone contain 16 chromosomes which are
20 genetically identical to those of the other drones. If a queen bee mates with
only one drone all the worker bees in the hive receive identical alleles from
the drone and all the genetic variation comes from the queen. If the queen
mates with two or more drones from different hives there will be greater
variation in the worker bees.
25 It has been difficult to improve the characteristics of bees by selective
breeding because bees do not mate as individual pairs. However, in the
colony there are a small number of virgin queen bees that have not yet
mated. These virgin queen bees can be used in selective breeding to form
new colonies.
What is meant by the term pollination (line 1)?
(1)
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