Gymnosperms

Question 1

What is a disadvantage of homospory?

Answer 1

The new sporophyte is dependent on a tiny gametophyte after zygote development

Question 2

How do you combat homospory?

Answer 2

The megagametophyte is retained inside the maternal sporophyte - as an ovule

Question 3

Explain seeds of conifers

Answer 3

• Seeds are in cones and not enclosed in a fruit
• Seeds develop on woody scales - bears 2 ovules each

Question 4

Explain pollen cones

Answer 4

• Contain microsporangia > produces microspores > become microgametophytes = pollen
• Dispersed by wind
• Pollen production is during spring

Question 5

Explain the life cycle of a conifer

Question 6

Explain other gymnosperm seeds

Answer 6

Serotinous cones: cones that require heat to release seeds

Aril: individual seeds surrounded by a fleshy seed coat (ex: yew, gingko and juniper berries)