reproduction 2

Question 1

Disadvantages of Homospory

Answer 1

• A developing embryo has to depend on a tiny gametophyte where
  
  • In heterospory, megagametophyte can be retained inside ovule

Question 2

The first seed plants

Answer 2

• Were gymnosperms
  
  • Resembled ferns
  • Medullosa

Question 3

Oldest seeds were

Answer 3

350 mya

Question 4

• In most conifers seeds are

Answer 4

in cones

Question 5

Pollen cones

Answer 5

• have Many microsporangia which produce microspores
  
  • Microspores develop into microgametophyte
  • Microgametophyte = Pollen

Question 6

Pollen

Answer 6

• Dispersed by wind(no water)
  - Vast quantities in spring

Question 7

pollen development process

Answer 7

1) Generative cell, Tube cell, Wings

2) Generative cell divides, producing spermatogenous cell and steril cell, tube cell elongates

3) Spermatogenous cell divdes, producing 2 sperm

Question 8

Seed cones

Answer 8

2) Seed cones
- Seeds develop on woody scales
- Each scale bears 2 ovules
After receiving pollen in summer, seeds are released

Question 9

Ovule

Answer 9

• Contains megasporangium
  - Nucellus = megasporangium
  - Integument = 2n
  - Micropyle is urethra of the thing
  - Female gametophyte is nutritious

Question 10

Fertilization
wtf happens w pollen and shit

Answer 10

• Pollen tube grows toward archegonium
  
  • A sperm unites with egg forming zygote within archegonium

Question 11

Serotinous cones

Answer 11

• Require heat to release seeds

Question 12

• Lodgepole pine and jack pine

Answer 12

Serotinous

Question 13

Yew

Answer 13

• Seed surrounded by red fleshy aril part of seed coat

Question 14

Ginkgo biloba seeds

Answer 14

• Seeds are enclosed in fleshy seed coat
  
  • Nauseating odor

Question 15

juniper

Answer 15

• Fleshy seed cones- not actually berries