Session Two (16.2.2): Conservation

Question 1

Define Conservation

Answer 1

Conservation is the process of looking after the environment; it attempts to maintain or increase biodiversity in an area.

Question 2

Explain what it means for a species to be ‘endangered’

Answer 2

A species whose numbers have fallen so low that is it at risk of becoming extinct.

Question 3

State 6 reasons why species can become endangered or extinct

Answer 3

• habitat destruction; climate change; pollution
• hunting; overharvesting
• introducing new species to an ecosystem

Question 4

Explain how introducing new species to an ecosystem can cause native species to become endangered

Answer 4

The new species may be a predator of some of the native species, or it may compete with them for scarce resources, such as food or nesting sites.

Question 5

Name 3 different tactics that can be used to conserve endangered species

Answer 5

• monitoring and protecting the species in its natural habitat
• using captive breeding programmes
• educating local people about the importance of conservation, and what they can do to help

Question 6

Seed banks

Answer 6

The facility in which seeds of different plant species, or crop varieties, are stored for long periods of time, in order to conserve as many different species and varieties as possible.

Question 7

Captive breeding

Answer 7

keeping animals in captivity (e.g. in a zoo) and allowing them to breed, in order to increase the numbers in the population.

Question 8

Define Artificial insemination (AI)

Answer 8

AI involves taking semen from the male and inserting it into the vagina of the female. In hopes of the sperm in the semen finding their way to an egg and fertilise it. The zygote will then develop into an embryo and implant into the uterus in the normal way.

Question 9

What are the conditions required before AI is carried out?

Answer 9

• The female must be at the correct stage of her reproductive cycle
• there must be a good chance that there is an egg in her oviducts

Question 10

Define in vitro fertilisation (IVF)

Answer 10

IVF involves collecting eggs from the female, placing them in a sterile liquid in a sterile container (such as a Petri dish) and then adding semen from the male. Fertilisation happens in the dish and several zygotes are formed. Some of these then divide to form tiny embryos. One or more of the embryos is then placed in the female’s uterus, with the hope that it will implant in the normal way, grow into a fetus and eventually be born successfully.

Question 11

What is required for IVF to be carried out?

Answer 11

• it is necessary to wait until a female ovulates naturally before eggs can be harvested
• the female needs to be in the correct stage of her reproductive cycle before embryos produced in vitro can be implanted

Question 12

Explain why genetic diversity is important to a population

Answer 12

If there is variation between individuals, then the population as a whole has a better chance of surviving if they are threatened by a pathogen, or if their habitat changes in some way. At least some of the individuals may have variations that allow them to survive and reproduce, even if others are killed.

Question 13

Explain why it is important to maintain genetic diversity when a captive breeding programme is undertaken.

Answer 13

Genetic diversity increases the chances that a population of organisms will be able to adapt to changes in their environment, such as climate change. It also reduces the chances of two harmful recessive alleles being brought together in the offspring of a breeding pair.

Question 14

Describe how genetic diversity is maintained among the seeds that are stored in a seed bank.

Answer 14

When seeds are collected from the wild, the collectors try to take them from different places, so that the plants that produced the seeds are not likely to be closely related. In the bank, some seeds are germinated every now and then, to produce fresh seeds for storage. When this is done, care can be taken to cross plants with different genotypes, to maintain genetic diversity among the seeds that are stored.

Question 15

State 5 reasons for conservation programmes

Answer 15

• to prevent species going extinct
• damaging ecosystems, cause harm to those who depend on locally collected resources to survive
• losing species can lead to disruption in food webs
• to prevent losing potential new medicines from plant species
• to prevent losing potentially useful alleles