Chapter 30: Plant diversity (seed plants) (2) Flashcards
Which phylum is by far the largest of the gymnosperm phyla?
Coniferophyta.
Most conifers are ____ and can carry out photosynthesis year round
Most conifers are evergreens and can carry out photosynthesis year round
Angiosperms are seed plants with reproductive structures called _____
Angiosperms are seed plants with reproductive structures called
– flowers and
– fruits
What is a flower and list out its structures.
A flower is a specialized shoot with up to four types of modified leaves
– Sepals, which enclose the flower
– Petals, which are brightly coloured and attract pollinators
– Stamens, which produce pollen
– Carpels, which produce ovules
Differentiate between complete and incomplete flowers.
- Complete flowers – have all four organs
- Incomplete flowers – lack one or more organs
Explain the life cycle of angiosperms
- Sporophyte flowers are composed of both male and female structures
- Male gametophytes are contained within pollen grains produced by the microsporangia of anthers
- Female gametophyte, or embryo sac, develops within an ovule contained within an ovary at the base of a stigma
What are the 2 cells within a male gametophyte?
Each male gametophyte has two haploid cells:
– a generative cell – divides to form two sperms
– a tube cell – produces the pollen tube
The ovule is entered via a pore called the _____
The ovule is entered via a pore called the micropyle.
Explain double fertilization.
- One sperm fertilizes egg
- Other sperm combines with two nuclei in the central cell of the female gametophyte and initiates development of food-storing endosperm
- The triploid endosperm nourishes the developing embryo
What is within a seed embryo?
Within a seed, the embryo consists of a
– root and
– two seed leaves called cotyledons
What do gymnosperms and angiosperms have in common?
- Both utilize seeds as the primary means of reproduction
- Both use pollen to facilitate fertilization.
- Both have a life cycle that involves the alternation of generations
- Both have a reduced gametophyte stage
Differentiate between angiosperms and gymnosperms.
- Gymnosperms have naked seeds, angiosperms have enclosed seeds
- Angiosperms are flowering plants while gymnosperms are not.
- Angiosperms use double fertilization.
- Angiosperms produce fruit.
- In angiosperms, the endosperm is triploid. Gymnosperm endosperm is diploid.
How are angiosperms divided?
Angiosperms were divided into two main
groups
– Monocots (one cotyledon)
– Dicots (two dicots
The clade __________ (“true” dicots) includes most dicots
The clade eudicot (“true” dicots) includes most dicots
______________ include flowering plants belonging to the oldest lineages
– Amborella
– Star anise
– Water lilies
Basal angiosperms include flowering plants belonging to the oldest lineages.
– Amborella
– Star anise
– Water lilies