21 Questions
What is the main characteristic of the gametophyte stage in plants?
It is haploid and produces haploid gametes by mitosis
What is the key feature of the sporophyte stage in plants?
It is diploid and produces haploid spores by meiosis
In alternation of generations, what gives rise to the sporophyte stage?
Fusion of haploid gametes
Where are spores produced in plants?
Sporangia
What makes spore walls resistant to harsh environments?
Sporopollenin
Which plant group also undergoes alternation of generations like plants?
Algae
What is the main function of the xylem in vascular plants?
To conduct water and minerals
Which of the following is a characteristic of the phloem in vascular plants?
It distributes sugars, amino acids, and other organic products
What is the primary function of roots in vascular plants?
To anchor the plant and absorb water and nutrients
What is the difference between microphylls and megaphylls?
Microphylls are leaves with a single vein, while megaphylls have a highly branched vascular system
What is the evolutionary advantage of increased height in vascular plants?
The reason is not explicitly stated in the text
What is the likely evolutionary origin of roots in vascular plants?
They evolved from subterranean stems
Which part of the moss plant produces flagellated sperm?
Antheridia
What is the main function of the sporangium in plants?
Produce spores
In bryophytes, which stage is primarily dominant in their life cycle?
Gametophyte stage
What is the function of apical meristems in plants?
Allow for primary growth
Which plant structure anchors the gametophytes to the substrate?
Rhizoids
What is the primary function of archegonia in plants?
Produce eggs
Which part of the plant is involved in meiosis to produce spores?
Sporophyte
What is the role of the seta in a moss plant?
Anchor the plant
Which plant structure is responsible for gas exchange in hornworts and mosses?
Stomata
Study Notes
Alternation of Generations
- Plants alternate between two multicellular stages: gametophyte (haploid) and sporophyte (diploid)
- Gametophyte produces haploid gametes by mitosis, which fuse to form a diploid zygote
- Sporophyte produces haploid spores by meiosis, which grow into new gametophytes
Derived Traits of Plants
- Multicellular embryos with placental transfer cells
- Walled spores produced in sporangia, resistant to harsh environments
- Apical meristems, responsible for growth and development
Transport in Xylem and Phloem
- Xylem conducts water and minerals, includes dead cells called tracheids
- Phloem consists of living cells, distributes sugars, amino acids, and other organic products
- Increased height in vascular plants provides an evolutionary advantage
Evolution of Roots and Leaves
- Roots anchor vascular plants, absorb water and nutrients from soil
- Leaves increase surface area, capture more solar energy for photosynthesis
- Two types of leaves: microphylls (single vein) and megaphylls (highly branched vascular system)
Origin and Diversification of Plants
- Fossilized spores and sporophyte tissue found in Cooksonia
- Land plants grouped into non-tracheophytes (nonvascular) and tracheophytes (vascular)
- Evolutionary relationships among plant groups, including Charophyta, Chlorophyta, and Embryophyta
Non-Tracheophytes (Bryophytes)
- Represented by three phyla: Bryophyta (mosses), Hepatophyta (liverworts), and Anthocerophyta (hornworts)
- Lack vascular tissue, have gametophyte stage dominant
- Examples of bryophytes, including raindrop-shaped gametophytes and sporophytes with peristome
Bryophytes – Gametophyte Stage
- Gametophytes produce antheridia and archegonia, which produce sperm and eggs
- Sperm swim through a film of water to fertilize eggs
- Zygote grows into a sporophyte, which produces spores
Bryophytes – Sporophyte Stage
- Sporophytes grow out of archegonia, consist of a foot, seta, and sporangium
- Discharge spores through a peristome, have stomata for gas exchange
Test your knowledge of plant alternation of generations which involves multicellular stages, gametophyte, sporophyte, and the production of gametes and spores through mitosis and meiosis.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
