Q's from Worksheets - Exam 2

What evolutionary advantages do seeds offer?

can survive various conditions, can travel farther from parent plant, partially developed embryo is more advanced than the sporophyte.

What evolutionary advantages does pollen offer?

could travel farther, no need for water

if the sexual generation gives rise to the gametes, what part of an angiosperm is sexual?

gametophyte

if the sexual generation gives rise to the gametes, what part of a bryophyte moss is sexual?

gametophyte (archegonia and antheridia)

Advantages of a reduced gametophyte generation?

helped protect the reproductive phae from mutations of the DNA, which could have been caused by increased amounts of ultraviolet and cosmic radiation present on land (compared to ocean environment). Mutation in diploid genomes can be masked by the presence of a nonmutated gene on a homologous chromosome.

What evolutionary advantages do fruit offer?

protects seeds, aids in seed dispersal. Fruit can also prevent germination (don't want the seed taking nutrients from the fruit)

Seedless vascular plants - Gametophyte dominant or sporophyte dominant?

sporophyte dominant

Gymnosperms - Gametophyte dominant or sporophyte dominant?

sporophyte dominant.

Advantages of vascular tissue

support against force of gravity - faster metabolism, faster growth faster, more efficient transport of water and sugars throughout plant

How do the bryophytes differ from the seedless vascular plants? How are they similar?

Bryophytes only: have no vascular tissue, no stems, no roots, no true leaves, no heights. They are gametophyte dominant. Seedless vascular plants have vascular tissue, and are sporophyte dominant. Both have antheridia and archegonia and spores for reproduction. Sperm is flagellated.

In the life cycle of an angiosperm, what cellular process always precedes formation of the sporophyte generation?

Fertilization. After that, zygote divides by mitosis.

Bryophytes - gameteophyte dominant or sporophyte dominant?

Gametophyte

Two kinds of land plants in which gametophyte is dependent on sporophyte?

Gymnosperms and angiosperms

Only kind of land plant in which sporophyte and gametophyte independent?

Seedless vascular plants

Advantages of seeds?

Seeds contain embryo, food source for its early development, and protective coating that allows it to survive periods of drying out. Embryo is in a more advanced state of development, higher chance of survival. LArger food source allows for both longer periods of dormancy and supports early growth phases of the seedling following germination. Food store also allows it to continue development of roots, stems, and leaves upon germination until the plant breaks through the soil surface and is capable of photosynthesis

Until the evolution of seed plants, land plants were dependent on the availability of water for reproduction. Explain why this was true. Explain how seed plants overcame the need for water in reproduction

Sperm needed to be able to swim to the egg before the evolution of the seed. Seed plants developed pollen, which could be dispersed by pollinators or wind. So long as they had some kind of pollinator, the sperm could make it to the egg.

Angiosperms - Gametophyte dominant or sporophyte dominant?

Sporophyte dominant

What evolutionary advantages do flowers offer?

The ovary of the flower protect female gametophyte from insects and other predators while attracting pollinators.

Advantages of roots and leaves

With increased surface area, roots could have more access to water/nutrients and could also store nutrients. With this extra energy, some cells could specialize in functions other than photosynthesis. Broad leaves allowed for more photosynthesis which would lead to more energy for the plant.

The seed is not a gamete... it is

a baby sporophyte

In the life cycle of an angiosperm, What cellular division process always precedes formation of the gametophyte generation?

meiosis

Seedless vascular plants, gymnosperms, angiosperms - sporophyte dependent on gametophyte for energy?

no

Bryophytes - Sporophyte dependent on gametophyte for energy?

yes