Manipulation of species Flashcards
what is selective breeding?
the process by which humans use animal breeding/ plant breeding to selectively develop particular traits
what are some examples of traits that might be favourable for selective breeding?
the Limousin cow has high muscle growth efficiency so is good for beef
the large white- hardy and produces good quality bacon
merino sheep produce the best quality wool
how will some farmer reduce the effect of inbreeding?
cross-breeding
what does inbreeding do?
narrows the gene pool making individuals more vulnerable to disease and undesirable traits becoming present
what is cross breeding?
involves taking two different breeds and crossing them together b
how can selective and cross breeding be done?
through artificial insemination
where is an example of cross breeding?
Jamaica milk industry
what did Jamaica cross breed?
the zebu cattle and the Ayrshire cattle
why were the ayrshire and zebu crossed?
zebu are good at tolerating heat and are hardy
the ayrshire are high milk producers but are not good in heat
what is asexual reproduction?
when there is only one parent
what are the characteritics of asexual reproduction?
the parent and ‘daughter’ are effectively identical as the offspring is a direct descendant of the single parent
what plants naturally produce asexually?
strawberries
banana plants
how can farmers artificially cause asexual reproduction?
taking cuttings of the best producing varieties
how does artificial asexual reproduction improve efficiency of farming?
desirable characteristics almost certain ad the survival rate is good
whata re the negatives of artificial asexual reproduction?
causes narrowing of the gene pool and can cause widespread disease within a crop if they don’t have disease tolerance
what is asexual reproduction in animals called?
cloning
is cloning done commercially?
no still in research phase
what will cloning allow for?
valuable animals to be replaced
allows us to replicate the characteristics of the ‘perfect’ farm animal without using the ‘perfect mother,
what is transgenics?
genetic engineering
what is genetic engineering?
involves extracting DNA from another organism’s genome and combining it with the DNA of that individual
when is genetic engineering used?
used by scientists to enhance or modify the characteristics of an individual organism
what are some examples of genetic engineering?
roundup ready soya
golden rice
BT maize
what is roundup ready soya?
soya that isnt affected by the roundup herbicide
meaning it can be used to kill weeds in a field without risking killing the crop
what is golden rice?
rice with additional nutritional value
added vitamin A due to deficiencies
what is BT maize?
genetically engineered to kill larvae that try to eat the crop
Endospore bacteria toxin
what are the advantages of GM?
More nutritious food.
Tastier food.
Disease- and drought-resistant plants that require fewer environmental resources (such as water and fertilizer)
Less use of pesticides.
Increased supply of food with reduced cost and longer shelf life.
Faster growing plants and animals.
what are the disadvantages of GM?
They might contribute to a rise in allergic reactions.
Genetic food can prompt allergic reactions from different foods.
GMOs may contribute to antibiotic resistance.
Some research has linked GMOs to cancer.
Very few companies are in charge of all the GMO seed market
what does increasing crop population density do?
can increase total yield although yield per individual may be reduced due to inter-species competition
can increase the rick of the rapid spread of disease
what is a monoculture?
a monoculture involves cultivating a single species, often over a lrge area
what is benefit of monoculture?
can make cultivation easier by allowing the use of larger machinery
what are the negatives of monocultures?
pests and diseases can spread rapidly if they colonise the field
what is the benfit of hedgerow removal?
create larger fields
what is the problme with removing hedgerows and other habitats?
can increase pest damage as natural predator habitats are lost
what was added to roundup ready soya?
a strain of bacterium Agrobacterium is resisant to the herbicide glyphophate
what was added to make BT crops (maize)?
bacterium Bacillus thuringiensis which naturally produces a toxin that kills insects
why was vitamin A added to rice?
as vitamin A deficiencies causes about 500,000 new cases of blindness each year especially in India and sub-saharan africa
what are the benefits of increasing optimum livestock/ crop density?
increase total yield
what are the negatives of increasing optimum livestock/ crop density?
yield per individual may be reduced due to inter-species competition
increased risk of rapid spread of disease
what are the benefits of asexual reproduction in plants?
offspring are genetically identical to parent plant so characteristics are predictable
survival rate is high
what is the method for asexual reproduction in animals? (cloning method)
cells removed from donor and grown in culture
egg removed from a female
nucleus egg removed and replaced by nucleus from donor cells
egg implanted in surrogate female, develops normal pregnancy
what is sexual reproduction?
the combination of genes from 2 parents characteristics cannot be predicted
what is artificial insemination? (AI)
semen collected from male with desirable characteristics used to impregnate females
what is the positive of AI?
many more young produced then natural mating
frozen semen more easily transported
frozen samples can be stored to produce offspring after male is dead
What is the process for embryo transfer?
hormone FSH stimulate ovulation (many eggs released)
eggs washed from uterus and collected
eggs fertilised with sperm from male with desirable characteristics
each fertilised embryo implanted in surrogate female
What is the positive of embryo transfer?
donor female can produce multiple embryos more frequently then offspring from normal pregnancies
what does increasing population density do?
can increae toal yield although yield per individual may be reduced due to inter species competition
can increase the rick of the rapid spread of disease
