Lecture 5 : Potato and other starch staples

What is starch

a polysaccharide, a linear polymer (chain) of glucose molecules

• broken down by enzymes in saliva

Amylase

ENZYME that breaks down starch

Stolons/runners

aboveground horizontal stems that produce buds/roots at nodes

EX: Strawberry

Rhizome

thick horizontal underground stems that spread the plant, new shoots come out of the nodes

EX: ginger, iris

Tuber

enlarged storage tips of a rhizome

EX: potato, yam

Bulb

short vertical underground stems with thick leaves

EX: onion, tulip, daffodil

Corm

short vertical underground stem, surrounded by thin leaf-like scales

EX: taro

Storage tap root

thickened main root

EX: carrot, turnip

Tuberous root

thickened portion of lateral root, became enlarged with food reserve

EX:

sweet potato, cassava, jicama

Darwin: Natural Selection - Variation

Members of a population have individual differences that are inheritable

Darwin: Natural Selection - Overproduction

Natural populations reproduce geometrically

Darwin: Natural Selection - Competition

Individuals compete for limited resources

Darwin: Natural Selection - Survival to reproduce

Only those individuals that are better suited to the environment survive and reproduce