Gymnosperms Overview

Practice flashcards for understanding key concepts of gymnosperms, including their traits, reproductive cycle, and differences among groups.

What is the nucellus?

Inner part of a plant ovule that contains the female gametophyte.

• Megasporangium → female sporangium

• Makes megaspores

What is the integument?

Protective (outermost) layer that surrounds the ovule in plants.

• dev. into seed coat

What is the micropyle?

Small opening in the integument of an ovule through which the pollen tube enters.

What are the shared traits of gymnosperms?

• P.S.

• Sporophyte, free living, dominant

• Heterosporous life cycle

• Male gamete dispersal via pollen

• Dispersal via seeds

• Sec. growth via vascular cambium

What represents the gametophyte generation in conifers?

The gametophyte generation is the pollen grains (male) and the ovule (female) found within the cones.

What represents the sporophyte generation in conifers?

The sporophyte generation is the conifer tree itself, which produces the cones with seeds.

What are the benefits of dispersing sperm via pollen compared to sperm in bryophytes and seedless vascular plants?

• Sperm no longer need H2O to swim to egg → good for dry conditions

• High potential for genetic diversity across pop. → benefit in diff. conditions

What are the benefits of dispersing offspring via seeds?

• Coat protects dev. embryo

• Nutritive tissue (megagametophyte) provides food for dev. seedling

• Easy dispersal (morphology + nutritional value)

• May lie dormant

  • seed banks = high gen. diversity

What is the purpose of the nutritive tissue in a gymnosperm seed?

Supplies essential nutrients to the developing embryo, supporting its growth until it can sustain itself.

From where does the nutritive tissue develop in seeds?

Also known as megagametophyte and female gametophyte, it devs. from haploid cells of female gametophyte

What are the three generations present in a gymnosperm seed?

The three generations are:

1. Embryo - the new plant that will grow.
2. Nutritive tissue - provides food for the embryo, derived from the female gametophyte.
3. Seed coat - the protective outer layer that comes from the parent plant's ovule.

Where do the nutritive tissue and seed coat develop in seeds?

Develops from the female gametophyte, while the seed coat originates from outer layer of ovule.

What environments do conifers thrive in?

Thrive in cold + dry regions

What are some adaptations of conifers?

• Tracheids

• Thin leaves

• Thick cuticle

• Sunken stomata

This limit water loss

• Evergreen for yr round P.S.

• High P.S. at low temps

What are evergreen trees?

Evergreen trees retain their leaves throughout the year and do not lose all their leaves at once.

What are deciduous trees?

Deciduous trees lose their leaves seasonally, typically in the fall, and regrow them in the spring.

What is pollination?

Pollen grain (microgametophyte) travels via wind to female cone (megagametophyte)

What is fertilization?

• Occurs after pollination → pollen tube grows

• Sperm cell from pollen merges with an ovule.

• Results in the formation of a seed.

What are the two main types of seed plants?

• Gymnosperms: Produce seeds in cones.
• Angiosperms: Produce seeds in flowers and fruits.

How do gymnosperms reproduce?

• They reproduce using cones for male (pollen) and female (seeds) parts.

How do angiosperms reproduce?

• They reproduce using flowers and often produce fruits that contain seeds.