Ch 29 + 30 plant diversity

what is the multicellular haploid generation in land plants?

gametophyte

In bryophytes what is the dominant generation?

gametophyte, They are the only type of land plant which has a dominant gametophyte

What did land plants probably evolve from 470 million years ago?

green algae

What type of life cycle do land plants have?

haplodiplontic cycle

While seedless vascular plants dominated the 300 million years ago, what replaced the seedless plants as the dominant land plant"

seed plants replaced the seedless plants as the dominant land plants and today, flowering seed plants (the angiosperms) are the most diverse and successful group of plants on earth

What are stomata?

small openings on a leaf through which oxygen and carbon dioxide can move

What is a (diploid) sporophyte?

spore producing plant (produces haploid spores)

What are the first cells of the gameotophyte generation?

spores

What are the tissue that carry water through the plant?

xylem

What type of life cycle do humans and other animals have?

A diplontic life cycle

All land plants have a common sexual reproductive cycle, what is it called?

Alternation of generation

What happens as a result of angiosperms efficient and more effective way of pollination?

As a result, the appearance of angiosperms greatly increased the pace of evolution and today, flowering plants account for over 90% of all plant species

As land plants have evolved what has been the occurring trend?

As they evolve, the trend had been toward more embryo protection and a smaller haploid stage in the life cycle.

Why can't bryophytes grow tall?

Because they lack a system to efficiently transport water.

How do land plants produce gametes?

By mitosis in a multicellular, haploid individual.

Are cones male or female?

Cones can be both male (bearing pollen) or female (bearing seeds).

what is the largest and best known of the four different phyla of gymnosperms?

Coniferophyta (conifers), which includes pines and other cone-bearing trees and shrubs.

what are the four different phyla of gymnosperms?

Coniferophyta, Cycadophyta, Gingkophyta and Gnetophyta

What is the function of stomata?

Control the entrance and exit of gases found in leaves

What occurs during the reproduction of bryophytes?

Diploid spores undergo meiosis within the sporangium to produce haploid spores. These spores are eventually released from the sporangium. If the spores land in a suitable damp location, they may germinate and grow by mitosis to form the next gametophyte generation. Eventually male gametangia (antheridia) and female gametangia (archegonia) form on the tips of the leafy gametophytes. A single egg is produced in the base of the archegonium and numerous sperm are produced within the antheridia. When the sperm are released they swim with the aid of flagella through a film of dew or rainwater to the archegonium and there, fertilization occurs as one haploid sperm unites with the haploid egg, forming a diploid zygote. The zygote divides by mitosis and develops into the stalk-like sporophyte generation

What does each rhizoid consist of?

Each rhizoid consists of several cells that absorb water, but in much lower volumes than would be absorbed by the roots of vascular plants.

All phototrophs are plants. True or False?

False, not all photoautotrophs are plants, some microorganisms are capable of photoautotrophy

How does the female gametophyte provide nutrients for the sporophyte embryo?

Through a unique triploid endosperm tissue

what is a gametophyte?

gamete producing plant

What are the most diverse and successful group of plants on earth?

Flowering seed plants (the angiosperms)

While the plant kingdom includes the green algae, what does it not include?

Fungi

How was Fungi essential to the colonization of plants?

Fungi enhanced plants nutrient uptake from the soil

Due to the cuticles impermeable nature it limits the gas exchange essential for respiration and photosynthesis, how does gas diffusion into and out of a plant occur then?

Gas diffusion into and out of a plant occurs through tiny mouth-shaped openings called Stomata(singular, stoma) on plant leaves and stems, which allow water to diffuse out at the same time.

In gymnosperms, two types of spores are produced (heterosporous) and they have...

Greatly reduced, microscopic male and female gametophytes

Why are gymnosperms better suited to drier land areas than ferns are

Gymnosperms have adaptations which benefit them in dry and cold environments such as: needle-shaped leaves with sunken pores and a thick, waxy cuticle covering them to reduce water loss and prevent damage by frost.

What does it mean to have a haplodiplontic life cycle?

Having multicellular haploid and diploid stages.

What are the two types of spores that are produced in gymnosperms?

Heterosporous

Briefly describe the life history of a Bryophyte.

In Bryophytes gametophyte is the dominant generation. There are divided into three clades liverworts, hornworts, and mosses. During reproduction in Bryophytes, Diploid spores undergo meiosis within the sporangium to produce haploid spores. These spores are eventually released from the sporangium. If the spores land in a suitable damp location, they may germinate and grow by mitosis to form the next gametophyte generation. Eventually male gametangia (antheridia) and female gametangia (archegonia) form on the tips of the leafy gametophytes. A single egg is produced in the base of the archegonium and numerous sperm are produced within the antheridia. When the sperm are released, they swim with the aid of flagella through a film of dew or rainwater to the archegonium and there, fertilization occurs as one haploid sperm unites with the haploid egg, forming a diploid zygote. The zygote divides by mitosis and develops into the stalk-like sporophyte generation

what is the male gametophyte contained in?

In a pollen grain

In all other plants besides bryophytes the dominate generation is...

In all other land plants, the diploid sporophyte is the dominant (more conspicuous) generation,

How is pollination in angiosperms different from gymnosperms?

In most angiosperms, pollination is facilitated by pollinators such as insects which are attracted to the flower because of its rewards of nectar or in some cases, edible pollen. The animal movements provide a precise placement of pollen on the receptive portion of the female structures, thus increasing the likelihood of fertilization. The process also enhances the opportunity for cross-fertilization among distant plants and therefore increases genetic variation and ultimately, the ability to adapt and evolve.

What is the life cycle of seedless vascular plants?

It is a variation of alternation of generations, in which the sporophyte is the dominant plant. The gametophyte is much smaller and is usually independent of the sporophyte

What is the waxy surface material on plants? what is its function?

It is the cuticle that is secreted onto parts of the plant that are exposed to the air in order to protect the plant from drying out. The cuticle is relatively impermeable, preventing water loss.

Describe the haplodiplontic cycle.

Land plants undergo mitosis after both fertilization (the diploid stage) and meiosis (the haploid stage). The result is a multicellular haploid individual (called the gametophyte).

Where does meiosis take place in the life cycle of land plants?

Meiosis takes place in structures called sporangia, where diploid spore mother cell (sporocytes) undergo meiosis, each producing 4 haploid spores

How do most gymnosperms spread their pollen?

Most gymnosperms produce huge amounts of pollen that is carried by the wind and reaches the appropriate species by chance.

what is the sporangium?

Multicellular organ on the sporophyte that produces and protects spores

What were the advantages of seeds?

Seed plants became free from the dependence on water for fertilization through the development of a process of internal fertilization via the pollen grain and the development of the seed which contains a dormant embryo with a protective seed coat and a supply of food stored within the seed, to fuel the early stages of development for the new plant.

Together what are charophytes and land plants referred to as?

Streptophytes

what does is mean to have a diplontic life cycle?

That only the diploid stage is multicellular.

What is another advantage that angiosperms have over gymnosperms?

The vascular tissue of angiosperms is also more efficient than that of the gymnosperms, The water-conducting xylem tissue, in addition to the narrow tracheids, also has large diameter vessels and the sugar-conducting phloem cells, called sieve-tube elements, provide more efficient transport of photosynthetic products.

What is the primary reason as to why seedless vascular plants are not found in dry areas?

The absence of the seed and the fact that they still have motile sperm that requires water for fertilization (standing water must be available for reproduction)

What is the axis?

The axis is anchored to a substrate by rhizoids (not true roots)

The green algae is split into two major groups: What are they?

The cholorphytes, which never made it to land, and the charophytes, which are a sister clade to all the land plants

How was the evolution of the flower beneficial?

The evolution of the flower greatly increased the efficiency of both the transfer and reception of pollen

What is another distinctive feature of angiosperms?

The fruit

What does the gametophyte of mosses consist of?

The gametophyte of mosses consists of small leaf-like structures (not true leaves because they lack vascular tissue) arranged around a stem-like axis (not a true stem). The axis is anchored to a substrate by rhizoids (not true roots). Each rhizoid consists of several cells that absorb water, but in much lower volumes than would be absorbed by the roots of vascular plants. The sporophyte generation are attached to the gametophyte and depend on them for nutrition. The stalk-like sporophyte contains a sporangium (spore capsule) at the top and usually turns brown or straw-colored when mature

What are the three evolutionary clades (groups) Bryophytes are divided into?

The liverworts, hornworts, and mosses

Of the three evolutionary clades which is the most widespread and diverse?

The mosses

In angiosperms what contains the male gametophyte?

The pollen grain

Describe the creation of a seed.

The pollen grain develops into a pollen tube, which delivers the sperm to the egg cell. After fertilization occurs, the embryo develops into the next sporophyte generation within the gametophyte tissues, which are protected by the previous sporophyte generation. The resulting seed is therefore protected from the outside environment and is also packed with food for the developing sporophyte.

How does the pollen grain remove the need for fertilization to occur by water?

The pollen grain is resistant to desiccation and is adapted for wind pollination.

How is fruit developed?

The seeds of the angiosperm develop within the flower ovary, which develops into the fruit.

what happened to seedless vascular plants when earths climate became drier?

The swampy areas declined and because of their limited adaptions to the terrestrial environment, their range was greatly reduced. And as such they are confined to areas that are moist enough, at least seasonally, to support their method of reproduction.

what are xylem cells called and how are they different from those found in other vascular plants?

The xylem cells are called tracheids and they are more efficient for transporting water than are those found in the seedless vascular plants.

How are tracheophytes able to grow tall?

They are more advanced, producing specialized vascular tissue for transport over long distances.

What type of plants are bryophytes(mosses, liverworts and hornworts)?

They are nonvascular or "nontracheophyte" plants

Describe the distinguishing features of a gymnosperm.

They are vascular plants and they have advanced vascular tissue: xylem for transporting water and nutrients up the plant and phloem for transporting photosynthetic products down the plant. There are four different phyla of gymnosperms, the largest and best known is coniferophyte.

What is a nonvascular plant?

They do not have tubes to carry food and water. They absorb water from their surroundings. They do not grow very tall. No roots- but have a "root-like" structure.

Briefly describe a generalized plant life cycle

They go through a sexual reproductive life cycle called alternation of generations where plants alternate between a haploid gametophyte generation and a diploid sporophyte generation.

What do land plants have unlike charophytes?

They have multicellular haploid and diploid stages, unlike the charophytes.

What were the first land plants?

They were the nonvascular Bryophytes (which include mosses, liverworts and hornworts).

Why are bryophytes not as well adapted to live in drier areas?

This is because they do not have certain types of cells that conduct water up a plant (as all "vascular" plants including all of the other types of land plants have). Because they lack these types of water conducting cells, they are generally not as well adapted to live in drier areas on land and are usually confined to moist or shaded areas.

Briefly explain how Seedless Vascular Plants are different from Bryophytes and why they are better suited toward somewhat drier environments.

Unlike bryophytes they posses' vascular tissue, which is specialized for conducting water, nutrients, and photosynthetic products. Because of this they can support themselves in dryer environments better then bryophytes. It is also a sporophyte dominant generation unlike bryophytes, and the life cycle of seedless vascular plants is a variation of alternation of generation, in which the sporophyte is the dominant plant. The gametophyte is much smaller and is usually independent.

what is the female gametophyte retained in?

Within the sporangium in the ovule of the sporophyte generation

Gymnosperms are vascular plants and they have advanced vascular tissues: what are they?

Xylem and phloem

Why do you think that Bryophytes are usually confined to wetter areas on land?

Yes, because when undergoing meiosis within the sporangium after then are released the spores need to be released into a suitable damp location so they can germanite so it would stand to reason that they would typically be confined to damp/wetter areas.

What do green algae and land plants share?

a common ancestor

What is a photoautotroph?

a photoautotroph is an organism that can harness sunlight to create energy via photosynthesis (e.g. plants)

are gymnosperms vascular or nonvascular?

vascular

what are sporocytes?

diploid cells that undergo meiosis to generate haploid spores

what is the ovule?

female gamete (female part of the plant)

In what way are sporophytes and bryophytes similar?

just as in the bryophytes, the haploid gametophyte generation of sporophytes produces the male and female gametes (eggs and sperm). Eggs are produced by mitosis in archegonia and sperm are produced in antheridia.

Describe how sporophytes reproduce?

just as in the bryophytes, the haploid gametophyte generation produces the male and female gametes (eggs and sperm). Eggs are produced by mitosis in archegonia and sperm are produced in antheridia. During fertilization, the gametes fuse, usually by entrance of the sperm into the archegonium. This produces a zygote, which develops into an embryo and eventually into the diploid sporophyte generation.

What is sporangia?

multicellular organs that produce spores

What adaptations benefit gymnosperms in dry and cold environments?

needle-shaped leaves with sunken pores and a thick, waxy cuticle covering them to reduce water loss and prevent damage by frost.

what is the tissue that carries food through the plant?

phloem

What happens in alternation of generations (plant reproductive cycle)?

plants alternate between a haploid gametophyte generation and a diploid sporophyte generation.

what are angiosperms?

plants that produce flowers as reproductive organs

what are gymnosperms?

plants that produce seeds without flowers (conifers and cycads) "naked seeds"

What are tracheophytes?

plants with vascular tissue

What is the multicellular diploid generation in land plants?

sporophytes

In angiosperms is reduced to...

the female gametophyte is reduced to just a multinucleated embryo sac

Briefly explain some of the evolutionary advantages that flowering plants have over all other types of plants.

the flower allows for more efficient pollination. The development of fruit is also a considerable advantage as it allows for the seeds to be spread to new environments. It is the "reward" the animals will eat and then through their fecal matter they spread the seeds to reach far and new environments. The vascular tissue of angiosperm is also more efficient than that of other gymnosperms; the water-conducting xylem tissue, in addition to the narrow tracheid, has large diameter vessels and sugar-conducting phloem cells, sieve tube elements, that provide more efficient transport of photosynthetic products. As well as their extensive ability to cross pollinate.

What is a gametophyte?

the gamete-producing and usually haploid phase, producing the zygote from which the sporophyte arises

what were the first seed bearing plants?

the gymnosperms

What do all land plants have?

they have both haploid and diploid generations, but there is an evolutionary shift toward a dominant diploid generation

What do seedless vascular plants possess that byrophytes lack?

they possess vascular tissue, which is specialized for conducting water, nutrients, and photosynthetic products.

what does phloem do?

transports photosynthetic products down the plant (ex. sugar)

what does xylem do?

transports water and nutrients up the plant