Manipulation of the food species

Question 1

Advantages of high population of both crops and animals

Answer 1

• increased yield
• pest control
• better soil health
• efficient land use

Question 2

Disadvantages of high population of both crops and animals

Answer 2

• increased competition
• disease spread
• soil degradation

Question 3

Advantages of low population of both crops and animals

Answer 3

• reduced competition
• lower disease risk
• improved soil health
• enhanced biodiversity

Question 4

Disadvantages of low population of both crops and animals

Answer 4

• lower yield
• vulnerability to pests
• limited genetic diversity

Question 5

Optimum population density changes for each farm/area and is dependent on:

Answer 5

• crop type
• soil quality
• water availability
• climate

Question 6

Definition of a monoculture

Answer 6

1 species covering a fairly large area
low genetic diversity

Question 7

Advantages of monoculture

Answer 7

• efficient harvesting
• minimal technology
• higher yield
• higher income

Question 8

Disadvantages of monoculture

Answer 8

• low genetic diversity
• increased disease
• low biodiversity - less stable

Question 9

Selective breeding description

Answer 9

Agents are selected with desired traits
Offspring then express these desired characteristics
Frequency increases over generations

Question 10

How have chickens been selectively bred for food consumption

Answer 10

Faster egg production - kept in battery cages, breed the hens which lay the most eggs
Faster meat production - kept intensively in large sheds, chose chickens with higher meat mass

Question 11

How have cows been selectively bred

Answer 11

For meat - ancestor had mutation ‘double muscling’
Disadvantages - causes difficulties when the cows give birth

Question 12

Example of selectively bred plant

Answer 12

Wild Mustard Plant - leaves used for kale and flower buds used for cauliflower

Question 13

Define crossbreeding

Answer 13

2 different varieties of the same species - genetically different

Question 14

What are the general characteristics of a crossbred hybrid breed

Answer 14

Traits of both parents - e.g. labradoodle
High genetic diversity
Bigger and stronger

Question 15

Example of a crossbred plant

Answer 15

Different varieties of a tomato
Characteristics: disease-resistant and high yield

Question 16

Example of a crossbred animal

Answer 16

Zebu (does well in hot climates) + Ayrshire (high milk yield)
Offspring - high milk yield, heat tolerant

Question 17

What is artificial insemination

Answer 17

Process of injecting a male semen into a females cervix when she is in oestrus

Question 18

Benefits of artificial insemination

Answer 18

Useful for breeds at risk
Ensures survival of rare gene pools
Diseases are less likely to spread - as women don’t have to be transported to the stud

Question 19

Describe the process of embryo transfer

Answer 19

Females + hormone FSH
Produce many eggs
Eggs collected and fertilised with desired sperm
Fertilised embryos implanted into surrogates

Question 20

Define asexual reproduction

Answer 20

Only using one parent for producing offspring identical to the parent

Question 21

Advantages if asexual reproduction

Answer 21

Occurs quickly
No need for mates
Lower risk of disease

Question 22

Disadvantages of asexual reproduction

Answer 22

No introduction of new genetics
Vulnerable to environmental change
Overpopulation

Question 23

2 methods of artificial vegetative propagation

Answer 23

Cutting
Micropropagation

Question 24

What is cutting

Answer 24

Take a cutting and add a rooting hormone
Then plant the cutting
And it will grow roots

Question 25

What is micropropagation

Answer 25

Choose a plant with good traits Sterilise the plant material - add to a nutrient rich gel (agar) Starts to grow shoots and roots The shoots separate and encourage more to grow Plant is moved to a field for further growth

Question 26

What is the process of cloning

Answer 26

Gather group of cells - placed into a nucleus They are fused using an electric shock Fused cells begin to divide normally Embryo is placed in the uterus of a foster mother

Question 27

Advantages of cloning

Answer 27

Preservation of endangered species Research and development Disease resistant

Question 28

Disadvantages of cloning

Answer 28

Ethical concerns Health issues Reduced genetic diversity High costs

Question 29

Define genetic engineering

Answer 29

Deliberate modification of the characteristics of an organism by manipulating its genetic material

Question 30

Define transgenics

Answer 30

An organism whose genome has been altered by the introduction of one or more foreign DNA sequences from another species

Question 31

2 examples of GM foods

Answer 31

Rice - disease resistant, insect resistant - high yield Cotton - insect resistant, herbicide tolerant - disease resistant

Question 32

Advantages of GM

Answer 32

Increase resistance to specific insects Increase pathogen resistance Introduce traits from other species

Question 33

Disadvantages of GM

Answer 33

Increase costs to farmers Reduce local indigenous crop diversity Escaping genes from GM crops into non GM crops

Question 34

What are auxins and what are they used for

Answer 34

Plant hormones - regulated growth Root development Fruit development

Question 35

What are gibberellins and what are they used for

Answer 35

Promote plant growth Seed germination Flowering promotion

Question 36

What is ethylene and what it is used for

Answer 36

Regulates plant growth Fruit ripening Flowering

Question 37

What are anabolic steroids and what are they used for

Answer 37

Mimic effect if testosterone - promote muscle growth Medical uses Physical appearance

Question 38

What is BST and what is it used for

Answer 38

Synthetic version of a naturally occurring growth hormone Milk production Economic benefits