BIO 115 Plant Exam I

Example of nonvascular plant

mosses

Example of seedless vascular plant

ferns

Example of seed plant

cone-bearing & flowering plant

True/False: plants originated from green algae

true

What are the similarities between plants and algae

Both are

• multicellular

• eukaryotic

• photosynthetic autotrophs

• contain cell walls made of cellulose

Characteristics of an aquatic environment

• buoyancy

• abundant water

• moderate temps

• filtered light

Characteristics of terrestrial environment

• no buoyancy

• limited water

• CO2 & nutrients in soil

• extreme temps

• unfiltered light

alteration of generations

the alteration of a sexual phase and an asexual phase in the life cycle of an organism

gametophyte

(sexual phase) is a haploid multicellular organism that developed from a haploid spore

sporophyte

(asexual phase) is a multicellular diploid organism that produces haploid gametes

Differences between animal and plant life cycles

Plants:

• exhibits alteration of generations

Animals:

• no alteration of generations

• haploid stage of life cycle consists of gametes only

• only adult form is diploid

• meiosis results in gamete production

Plant life cycle

1. Zygote (single cell, diploid) undergoes mitosis

2. Adult sporophyte (multicellular, diploid) undergoes meiosis

3. Spore (single cell, haploid) undergoes mitosis

4. Adult gametophyte (multicellular, haploid) undergoes maturation → no meiosis

5. Gamete (single cell, haploid) undergoes fertilization

True/False: the gametophyte stage became increasingly dominant over the sporophyte stage

false

sporangia

multicellular organs that produce spores

sprorpellenin

located on the walls of spores, these protect spores from dry environments

apical meristems

where plant cells divide, are located at the tips of roots & shoots; cells here can divide throughout the plants life

stomata

specialized pores on leaves that allow the gas exchange for photosynthesis and the water to evaporate in the air

phyla that are seedless vascular plants

lychophytes & monilophytes

seed

consists of an embryo and its food supply, surrounded by a protective coat that when mature, are dispersed from their parent allowing them to colonize distant locations

gymnospem seeds

“naked” seeds that are not enclosed in chambers

angiosperm seeds

seeds developed inside chambers

True/False: gymnosperms contain all flowering plants

false; flowering plants are angiosperms

percentage of living plant species that are flowering plants

90%

number of phyla that extant plants are divided into

10

bryophytes

nonvasular plants

vascular plants

contain vascular tissue, which are tubes used for water and nutrient transport throughout the plant body

Which of the following outcomes is most likely if animals had alteration of generations?

1. products of meiosis would immediately fust to form a zygote and then undergo mitosis

2. the products of meiosis would undergo mitosis and become multicellular

3. the products of meiosis would undergo mitosis and remain unicellular

4. they would have twice as rapid a population growth rate as compared to their current rates

the products of meiosis would undergo mitosis and become multicellular

The multicellular haploid generation in plants is call the

gametophyte

Which biological molecule contributes to the structural integrity of plant spores?

sporopollenin

compare & contrast gametophyte and sporophyte

gametophyte:

• sexual phase, a haploid multicellular organism that results from a haploid spore

• produce gametes through mitosis

sporophyte:

• asexual phase, a diploid multicellular organism that produces haploid gametes

• produce spores through meiosis

Identify the four derived traits that distinguish plants from green algae and facilitate life on land.

1. Alteration of generations

2. Sporangia

3. Apical meristems

4. Stomata

haploid gametophytes

dominant stage of a moss’s life cycle in bryophytes and are usually larger and longer-living than diploid sporophytes

Moss Life Cycle

1. spores develop into protonemata

2. haploid protonemata produces “buds” that divide by mitosis and become gametophytes

3. sperm swim through a film of moisture to reach the egg to accomplish fertilization

4. zygote develops into a sporophyte embryo

5. sporophyte grows a long stalk (seta) that emerges from the archegonium

6. attached by the foot, the sporophyte remains nutritionally dependent on gametophyte

7. meiosis occurs and haploid spores develop in the capsule; when capsule is mature, lid pops off and releases spores

protonemata

branched, one-cell thick filaments that are produced by germinating moss spores

True/False: in mosses, there are female and male gametophytes

true

True/False: there are no bisexual gametophytes in the bryophte phyla

false

antheridium

male gametophyte in a moss that produces sperm

archegonium

female gametophyte in a moss that produces one egg

rhizoids

structure that anchor gametophytes to the ground

True/False: the sporophyte remains attached to its parental gametophyte throughout its lifetime in a moss

true

peristomes

the upper part of the sporangium has a ring of these interlocking, tooth-like structures

foot

in a moss, this absorbs nutrients from the gametophyte

seta

in a moss, this transports nutrients to the sporangium

sporangium

produces spores in a moss

True/False: ferns are the most widespread seedless vascular plants

true

fern life cycle

1. Sporophyte Stage (Diploid): The fern plant we commonly see is the sporophyte, which is diploid (2n), and it produces spores through meiosis in structures called sporangia.

2. Spore Production (Haploid): Within the sporangia, meiosis occurs to produce haploid (n) spores, reducing the chromosome number by half.

3. Germination of Spores (Haploid): The haploid spores germinate to grow into a small, heart-shaped gametophyte, also known as a prothallus, through mitosis.

4. Gametophyte Stage (Haploid): The gametophyte is haploid (n) and produces male (antheridia) and female (archegonia) sex organs through mitosis.

5. Gamete Production (Haploid): Within the antheridia and archegonia, haploid gametes (sperm and eggs, respectively) are produced by mitosis.

6. Fertilization (Diploid): Sperm from the antheridia swim to the eggs in the archegonia, where fertilization occurs, producing a diploid zygote.

7. Development of New Sporophyte (Diploid): The zygote grows into a new sporophyte (2n), typically emerging from the gametophyte, completing the cycle.

leaves

primary phtosynthetic organ

microphyll leaves

small, simple leaves with a single, unbranched vein, characteristic of lycophytes such as club mosses

megaphyll leaves

large, often complex leaves with multiple veins and a branching vein pattern, characteristic of most ferns and seed plants.

classifications of vascular plants

xylem and phloem

xylem

conducts most of the water and minerals

phloem

distributes sugars, amino acids, and other organic products

roots

organ for water and nutrient uptake

sporophylls

modified leaves bearing sporangia

sori

clusters of sporangia on the undersides of sporophylls

homosporus

most seedless vascular plants; one type of sporophyll bearing one type of sporangium that produces single type of spore

heterosporous

all seed plants; produces two types of spores (male or female) from two types of sporophylls

The dominant generation in the vascular plant life cycle is the

sporophyte

Seedless vascular plants are homosporous, meaning they produce ________ type(s) of spore that develop(s) into ________ gametophytes

one; bisexual

In ferns, the gametophyte develops sperm-producing organs called _______ and egg producing organs called ________

antheridia; archegonia

In ferns, meiosis occurs inside a structure called the

sporangia

evolutionary advantage of seeds over spore

1. spores are single-cell but seeds are multicellular and have a seed coat

2. seeds have a supply of stored food and spores do not

3. seeds can remain dormant and live longer while spores have a shorter life span

megaspores

produced by megasporangia that give rise to female gametophytes (eggs)

microspores

produced by microsporangia that give rise to male gametophytes (sperm)

pollen grain

consists of a male gametophyte enclosed within the pollen wall

exine

the outer layer of a pollen grain, made by sporophyte cells

sporopollenin

found the in exine, protects the pollen grain

True/False: pollen grains cannot swim

true, they are carried by wind or animals

pollenation

the transfer of pollen to the ovules

ovule

the combined structure of the megasporangium, megaspore, and their integument

integument

a layer of sporophyte tissue that envelops and protects the megasporangium

gymnosperm megasporangia are surrounded by ______ integument; angiosperms usually have _____ integuments

one; two

pollination process in a gymnosperm

1. unfertilized ovule - a fleshy megasporangium is surrounded by the integument. The opening, micropyle, allows entry of a pollen grain

2. fertilized ovule - megaspore develops into a female gametophyte, which then produces an egg; the pollen grain that entered through the micropyle develops into a male gametophyte, which develops a pollen tube meant for discharging sperm

3. gymnosperm seed - fertilization transforms the ovule into a seed containing a sporophyte embryo, a food supply, and protective seed coat

True/False: reduced gametophytes is another key plant adaptation to the land

true

What adaptations have enabled seed plants to make up the majority of plant biodiversity?

1. reduced female and male gametophytes develop in sporophytes and are protected from environmental stresses

   1. in gymnosperms, this happens in cones

   2. in angiosperms, this happens in flowers

2. pollen protects male gametophytes and can be transported by wind or animals

3. ovules protect female gametophytes

4. fertilized ovules develop into seeds

A see contains all the following except ________

1. food supply

2. gametes

3. seed coat

4. embryo

gametes

Which of the following is an advantage seeds have over spores?

1. seeds have a supply of stored food and a protective coat

2. seeds can survive through unfavorable conditions

3. seeds are unicellular and have low nutritional demand

4. seeds can survive for extended periods of time

seeds have a supply of stored food and a protective coat

Which of the following is not a derived trait of seed plant?

1. ovules

2. pollen

3. vascular tissue

4. reduced gametophytes

vascular tissue

Seed plants are ________________, meaning they produce two types of spores that develop into male and female gametophytes

heterosporous

List the four phyla of a gymnosperm

cycadophyta, ginkgophyta, gnetophyta, coniferophyta

pine life cycle

- Mature Sporophyte (Diploid): A mature pine tree, the sporophyte (2n), produces both male pollen cones and female ovulate cones.

- Microsporocyte Meiosis (Diploid to Haploid): In the pollen cones, diploid microsporocytes undergo meiosis to produce haploid microspores, which develop into pollen grains (male gametophytes).

- Pollination (Haploid): Pollen grains are carried by the wind to the ovulate cones, where they land on the ovules and germinate, forming a pollen tube.

- Megaspore Formation (Diploid to Haploid): In the ovulate cone, meiosis occurs within the megasporangium, producing haploid megaspores, one of which survives to become the female gametophyte.

- Female Gametophyte Development (Haploid): The surviving megaspore develops into the female gametophyte within the ovule, which contains archegonia with egg cells.

- Fertilization (Haploid to Diploid): The sperm cells from the pollen tube fertilize the egg cells in the archegonia, resulting in a diploid zygote.

- Seed Development (Diploid): The zygote develops into an embryo within the seed, which also contains a food supply and is encased by a seed coat from the mother plant.

- Seedling Growth (Diploid): The seed eventually falls to the ground, and under favorable conditions, it germinates to produce a seedling that will grow into a new pine tree, continuing the cycle.

microsporocytes

cells producing microspores in microsporangia

Pollen cones have modified leaves that bear _________, which are the site of meiosis for creating pollen grains

1. megasporangia

2. sori

3. ovules

4. microsporangia

microsporangia

the gymnosperm phylum that contains only one extant species is

ginkgophyta

organisms in this phylum have large cones and palmlike leaves

cycadophyta

in ovulate cones, megasporocytes undergo ___________ to produce haploid megaspores

meiosis

basal angiosperms

living lineages that diverged early in the history of angiosperms

monocots

has one cotyledon; ¼ of angiosperm species (maize, rice, and wheat)

eudicots

has two cotyledons; over 2/3 of angiosperm species (legumes, roses, strawberries, apples, oak, willow)

Which angiosperms produce and contain seeds?

flowers and fruits

flower

specialized for sexual reproduction, a unique angiosperm organ that makes pollination by insets/other animals possible

sepals and petals

sterile floral structures that don’t produce sperm or eggs

stames

microsporophylls in a flower that produce microspores that form pollen grains which contain male gametophytes

parts of a stamen

filament and anther

anther

terminal sac where pollen is produced in a stamen

filament

the stalk of a stamen

carpels

megasporophylls that produce megaspores which form female gametophytes and consists of stigma that receives pollen, a style connecting the stigma and ovary containing one or more ovules

True/False: flowers can have more than one carpel

true

One cotyledon, parallel veins, and fibrous root systems are all characteristics of

monocots