Marine Biotechnology

Question 1

What is Biotechnology

Answer 1

applications of Biological processes for industrial or other purposes

Question 2

How has biotechnology been used?

Answer 2

• Bacteria that digest oil
• Selective breeding of organisms
• Genes can be transferred from one organism to another

Question 3

What do genes code for?

Answer 3

proteins

Question 4

How can oil form spills be removed?

Answer 4

By bioremediation

Question 5

What is bioremediation?

Answer 5

the decomposition of pollutants by microbes

Question 6

How does bioremediation work?

Answer 6

Several species of naturally occurring bacteria can use the hydrocarbons found in crude oil as an energy source for respiration.

They break down and remove oil present in water.

Different species of bacteria tend to ‘specialise’ in metabolising or breaking down just a few of the different components of oil and release carbon dioxide and water as waste products.

In order to remove an oil spill completely, several different bacteria are necessary.

Question 7

What are the factors that affect the speed at which the bacteria are able to break down and remove an oil spill

Answer 7

• Oxygen concentation
• Mineral ion concentration
• Water temperature
• Chemical and physical properties of oil
• pH and salinity

Question 8

How does oxygen concentraion affect the speed at which bacteria are able to break down?

Answer 8

the bacteria are aerobic and break down oil faster when oxygen concentrations are high

Question 9

Explain the breakdown of oil spills in relation to oxygen concentration

Answer 9

The breakdown is fastest in surface waters, where oxygen concentrations are higher, and slowest in deep water

Question 10

How does water movement affect oil removal

Answer 10

Water movements speed up oil removal by preventing the oil settling to lower depths where the oxygen concentrations are lower

Question 11

How does mineral ion concentration affect the speed at which bacteria are able to break down?

Answer 11

bacteria require mineral ions, including nitrates and phosphates, so if concentrations are low, bacterial growth rates are low and oil breakdown is slow

Question 12

How does water temperature affect the speed at which bacteria are able to break down?

Answer 12

oil is usually broken down faster in warmer water

Question 13

Explain how water temperature affects oil break down.

Answer 13

-The enzymes that catalyse the metabolism of the oil work faster in higher temperatures but will denature if the temperature becomes too high

Question 14

What happens when water temperature is low

Answer 14

Cold water can, however, cause surface oil to evaporate more slowly so that there is more oil for the bacteria to break down.

Oil also becomes more viscous when cold and clumps together, reducing the surface area exposed to the bacteria.

Question 15

How does Chemical and physical properties of oil affect the speed at which bacteria are able to break down?

Answer 15

crude oil from different parts of the world can vary in hydrocarbon composition. Some hydrocarbons are decomposed more quickly than others.

Question 16

How does pH and salinity affect the speed at which bacteria are able to break down?

Answer 16

extreme pH and salinity tend to slow bacterial activity

Question 17

What happens during oil spills?

Answer 17

bacterial growth is often encouraged

Question 18

State the methods used to encourage bacterial growth

Answer 18

• Suspensions of live bacteria
• Dispersants
• Fertilizers

Question 19

What is done with Suspensions of live bacteria to combat oil spills?

Answer 19

They are sprayed onto affected beaches and directly into affected water

Question 20

How are dispersants used to combat oil spills?

Answer 20

Dispersants are used, often by spraying from airplanes which help to break up the oil spill and are often used to protect beaches and coastlines from the oil.

By physically breaking up the oil slick and dispersing it in the water, they increase the contact of bacteria with the oil, speeding up chemical breakdown.

Question 21

How are fertilizers used to combat oil spills?

Answer 21

Fertilisers are sprayed onto the beaches and in the water to encourage microbe growth and speeds up the breakdown of the oil

Question 22

What is selective breeding?

Answer 22

parents with advantageous characteristics are chosen by humans, to produce offspring with advantageous features

Question 23

What is a gene?

Answer 23

a length of DNA that codes for a specific polypeptide (protein)

Question 24

What are the attributes of a gene?

Answer 24

• they are units of heredity (inherited)
• they can exist in alternative forms (called alleles)
• alleles can be dominant or recessive

Question 25

What is a genotype?

Answer 25

the genetic constitution of an organism, for the character under consideration

Question 26

What is a phenotype?

Answer 26

the physical appearance or particular character of an organism

Question 27

What does a phenotype depend on?

Answer 27

the interaction of genes and environment

Question 28

What can selective breeding be used for in marine aquaculture?

Answer 28

- Increased growth rate - Disease and stress resistance - Product quality - Age of sexual maturation

Question 29

Why is the need to increase growth rate important in aquaculture?

Answer 29

fish and shellfish that grow more rapidly or more efficiently (better food conversion) will reach market size more rapidly and waste less food, making more money

Question 30

Why is disease and stress resistance important in aquaculture?

Answer 30

because of high stocking densities in aquaculture there is increases the risk of disease transmission, stress and accumulation of toxins. Organisms that have some resistance to these stressors grow more rapidly and have a lower death rate.

Question 31

Why is product quality important in aquaculture?

Answer 31

the quality of fish or shellfish meat (colour, flavour and nutritional composition) is commercially very important. Products that are appealing to consumers generate higher profits.

Question 32

Why is the age of sexual maturation important in aquaculture?

Answer 32

delayed sexual maturation is often desirable because it ensures that organisms put more energy into growth rather than gamete production, increasing profits

Question 33

How would aim to breed fish to have a longer average length?

Answer 33

- selectively cull those fish that have a lower length than required (removing those fish from the population) - remaining fish that have alleles for longer body length are allowed to breed and produce offspring - Offspring below a certain length are culled again. - This is repeated over several generations until fish with the desired body length are obtained.

Question 34

What is cross breeding?

Answer 34

mating together different varieties of organism

Question 35

What are the risks of selective breeding?

Answer 35

- Inbreeding depression | - Escape into the wild

Question 36

What is Inbreeding depression?

Answer 36

the reduced biological fitness in a given population as a result of inbreeding, or breeding of related individuals

Question 37

What risk does inbreeding depression have?

Answer 37

- All organisms carry ‘hidden’ recessive alleles that have no effect because in the heterozygous condition they are masked by a dominant allele. - When populations become inbred, the chance of two parents carrying similar recessive alleles becomes higher. - selective breeding carries a risk of passing on harmful recessive conditions that appear in the offspring

Question 38

How is escape to the wild a risk of selective breeding?

Answer 38

escaped farmed salmon interbreed with the wild salmon and may have negative impacts on the wild populations

Question 39

What happens to to hybrid salmon?

Answer 39

- grow faster - are more competitive when feeding - are more aggressive than the wild-type salmon - however less likely to avoid predators