Plants- Asexuals Reproduction In Plants

Question 1

Asexual reproduction

Answer 1

single parent produces offspring that are genetically identical through mitosis

Question 2

How do they reproduce asexually

Answer 2

Modified stems – rhizomes, corms, stolons, “eyes” on tubers (e.g. potato)

Fragmentation – growth from a piece of a root or shoot

Question 3

Benefits

Answer 3

If plant is successful in its environment due to a genetic trait, all its offspring will be equally successful

Don’t require specialized reproductive structures, therefore requires less energy and reproduction occurs faster

Don’t require a “mate” (or pollinator), no wasted resources to attract

“Plantlets” produced from asexual reproduction are stronger than young seedlings produced in sexual reproduction (higher survival rate)

Question 4

Costs

Answer 4

Lack of variation – If environment changes significantly, the population may no longer be best suited to the new conditions, leading to the death of the population

Less chance of dispersal, so more competition

Question 5

Human uses of A.S reproduction

Answer 5

Small scale cloning – e.g. use cuttings to produce many copies of ideal plants

Large-scale cloning – use tissue culture propagation to produce large numbers of clones (treat meristematic cells with hormones to stimulate them to grow into a plantlet)

GRAFTING – a young branch (SCION) from a desirable tree is attached to the stem of another tree (STOCK), where the vascular tissue of the two eventually fuse
-Scion chosen for leaves, flowers or fruits, stock chosen for its roots

Question 6

Benefits of grafting

Answer 6

Benefits – multiple fruits in one, earlier fruiting, dwarfing, improved hardiness, pest/disease resistance
Common in orchards and vineyards – limited to no genetic diversity