Asexual/Sexual Reproduction and Improved Food Crops Flashcards
What did the domestication of wild plants lead to?
- great phenotypic change (and altered genotypes) resulting in vastly improved food crops
- new varieties developing
What are wild plants?
- plants that grow in nature without the aid of humans
What are some examples of asexual reproduction in plants to improve food crops?
- division
- grafting
- using storage organs (bulbs, corms, tubers and rhizomes)
- cuttings
What is grafting?
- a technique whereby tissues from one plant are inserted into those of another so that the two sets join together
What are the specifics of grafting?
- one plant is selected for its roots: the rootstock
- the other plant is chosen for its superior fruits and is called the scion
What is an example of sexual reproduction in plants to improve food crops?
- cross-pollination of individuals of a species to produce new crop varieties with improved traits
How can plant breeders help solve the current food crisis?
- by using asexual/vegetative propagation and genetic engineering techniques
How could asexual reproduction benefit future crop production in terms of speed?
- propagation is faster than from seed because there is no gamete formation, pollination, etc
- the grafting technique means fruit trees will grow more quickly to maturity and thus to fruit production
How could asexual reproduction benefit future crop production in terms of quality?
- all the propagated plants are of a consistent superior quality
How could asexual reproduction benefit future crop production in terms of quantity?
- large quantities of plants can be produced cheaply, easily and quickly
- eg by cuttings, perennating organs
What is a way that asexual reproduction can benefit future production?
- by micro-propagation (tissue culture) numerous new identical plants (clones) are produced
Why is micro-propagation favoured over traditional crop breeding methods in terms of seasonal change?
- propagation can take place all year independent of seasonal changes
What is tissue culture or micropropagation?
- a process whereby a small amount of plant tissue is cultured in a growing medium to produce a callus and then plantlets
Why is micro-propagation favoured over traditional crop breeding methods in terms of speed?
- commercially important crop plants can be mass propagated in a very short period of time
Why is micro-propagation favoured over traditional crop breeding methods in terms of disease?
- disease-free plants can be produced by selecting disease-free cells and culturing them in sterile conditions
