Lecture 23- Seed Plants

Question 1

what are the two types of seed plants?

Answer 1

gymnosperm
angiosperm

Question 2

what are the 3 common traits of seed plants?

Answer 2

ovuole
heterosporous
reduced gametophytes

Question 3

what does an ovule consist of in gymnosperms?

Answer 3

megasporangium
megaspore
one integument

Question 4

what does an ovule consist of in angiosperms?

Answer 4

megasporangium
megaspore
two integuments

Question 5

what does heterosporous mean?

Answer 5

there are two types of spores that the megasporangia produce

Question 6

what are the two types of spores and how do they differ?

Answer 6

female gametophytes
male gametophytes

Question 7

what are advantages to having reduced gametophytes? (3)

Answer 7

protection from environmental stresses
ovule protects from UV
can obtain nutrients from parent plant

Question 8

what are four evolutionary advantages to seeds in comparison to spores?

Answer 8

they retain in dormancy until environment is favorable
have a supply of stored food
may be transported long distances by wind or animals
have multicellular embryos (spores are single celled)

Question 9

what does seed dormancy increase the chances of?

Answer 9

germination will occur in favor of the seedling (the right time and place)

Question 10

what environmental cues does the breaking of seed dormancy require?

Answer 10

temperature
lighting
moisture

Question 11

germination depends on imbibition, what is that?

Answer 11

the uptake of water due to low water potential of a dry seed

Question 12

microspores develop into pollen grains, what do they contain?

Answer 12

male gametophytes

Question 13

what happens when a pollen grain germinates?

Answer 13

pollen tube discharges sperm into female gametophyte