Chapter 37- Vegetative Plant Development

Question 1

what happens to the 2 sperm released into the angiosperm embryo sac

Answer 1

one sperm fertilizes polar nuclei and initiates 3N endosperm development
-other sperm fertilizes the egg to produce a 2n zygote

Question 2

What does the zygote form into after development

Answer 2

2 things:
small cell divides repeatedly forming a ball of cells=embryo
large cell divides repeatedly forming an elongated structure=suspensor

Question 3

When does the primary meristem form

Answer 3

differentiate while the plant embryo is still at globular stage

Question 4

when does the outer protoderm from

Answer 4

develops into dermal tissue that protects the plant

Question 5

what does the ground meristem become

Answer 5

develops into ground tissue that stores food and water

Question 6

what does the inner procabium become

Answer 6

develops into vascular tissue that transports water and nutrients

Question 7

what are three critical stages angiosperms go through during embryogenesis

Answer 7

1. development of food supply
2. development of a seed coat
3. development of fruit surrounding seed

Question 8

What are 4 important benefits of a seed

Answer 8

1. they maintain dormancy under unfavorable conditions
2. they protect the young plant when it is most vulnerable
3. they provide food for the embryo until it can produce its own food
4. they facilitate dispersal of the embryo

Question 9

what grows first from the seed

Answer 9

root system, then shoot system

Question 10

when does germination take place in a seed?

Answer 10

when water and oxygen reach the embryo through cracks in the seed

Question 11

what are fruits

Answer 11

mature ovaries (carpels)

Question 12

how are fruits dispersed (5 ways)

Answer 12

• ingestion and transportation by vertebrates
• hitching a ride with hooked spines on animals
• burial in catches by herbivores
• blowing in the wind
• floating and drifting on water

Question 13

what is germination defined as

Answer 13

the emergence of the radicle (first root) from the seed coat

Question 14

what does the embryo produce if conditions are right for germination

Answer 14

gibberellic acid

-breaks down the endosperms starch into sugars that are passed to embryo

Question 15

what does the embryo produce if conditions are not right for embryo production

Answer 15

abscisic acid

-inhabits starch breakdown and establishes dormancy

Question 16

what happens to shoots in dicots

Answer 16

the hypocotyl (stem) emerges first and then the flowery section rises up to germinate

Question 17

what happens to monocots during germination

Answer 17

shoot and roots grow at the same time and the embryo stays in the ground