lec 3

Question 1

what are the primary functions of roots?

are there any limits on root size - ie what happens if roots are too big/small?

Answer 1

• support shoot
• absorb water + minerals
• prod some hormones (ex. cytokinins)

root size cant be too small or they’ll be unable to obtain nutrients/water. if they’re too big, it’s inefficient and a waste of resources

Question 2

what are the components of the distal root

Answer 2

1. area of maturation
   - root hairs
2. area of elongation
3. area of cell division
   - apical meristem
   - root cap

Question 3

what is the adventitious root system?

Answer 3

roots that form from nonroot tissue - ie from wounds on detached stems or leaves, or even just regular intact stems

Question 4

if we were to classify the reproductive organs into three groups, what would they be? from where did the reprod organs originate, anyways?

Answer 4

flowers (sepal + petals), stamen (contains sperm), and pistil (contains egg)

reprod organs are modified shoots, changed from axillary buds to reprod tissue

Question 5

we can categorize plants based on length of life. what are these categories?

Answer 5

annual: live less than a year

perennial: live longer than a year

biannual: subset of perennial that live two years
- first year decoted to growth
- during winter, the plant goes dormant but the roots persist
- following spring, they grow briefly, flower, prod seeds, and die

Question 6

arabidopsis thaliana is a model species for labwork. why?

Answer 6

short generation time of about 6 weeks - great for experiments :D

Question 7

we can categorize plants based on how many times they reprod. what are these categories?

Answer 7

monocarpic: reprod once (annuals + biennials)

polycarpic: reprod many times (perennial)

Question 8

we can categorize plants based on stem. what are these categories? which do annuals, perennials, and biennials fit under?

Answer 8

herbaceous plants: soft and fleshy
- mostly annuals, but some perennials too, such as tulips and some herbs

woody plants: woody

Question 9

describe woody plants. what is the wood, and what is the bark?

Answer 9

begin as herbaceous, but develop a woody cambium layer bw the xylem and phloem

secondary xylem cells grow inward (wood)

secondary phloem cells grow outward (bark)

Question 10

what are the two nonreprod parts of a flower? what are their roles

Answer 10

sepal: protect the developing flower

petals: attract pollinators through bright colours + scents

Question 11

what are the two reprod parts of a flower? what are their general roles and respective components?

Answer 11

stamen (sta-MEN): produces pollen
- anther (head): sends out pollen
- filament (shaft): tube to send pollen up + out

pistil (women should have guns): contains eggs
- stigma: pollen receptor
- style (stylus is long): tube that brings pollen down
- ovary: where ovules are contained

Question 12

from where do fruit develop?

Answer 12

fruit develop from the ovary once its pollinated

Question 13

perennials live longer than annuals. what would perennials have that annuals would not?

Answer 13

perennials need to have elements to deal w nature - ie more defensive mechanisms against the elements, pests, pathogens, etc

Question 14

what is the cambium, and where is it found?

Answer 14

cambium is a layer that grows between the inner xylem and outer phloem in woody plants.

Question 15

classify the following as annual, biennial, or perennial

• beans
• beets
• cabbage
• carrots
• oats
• wheat

Answer 15

annual: wheat, oat, beans

biennials: beets, cabbage, carrots