Chapter 22 Plants Flashcards
What is a plant?
eukaryotes that have cell walls containing cellulose and carry out photosynthesis using chlorophyll a and b
What is alternation of generations?
the shift between haploid and diploid
What adaptations do some plants have that allow them to live on land? (3)
- more resistant to the drying rays of the sun
- more capable of conserving water
- more capable of reproducing without water
Are all plants autotrophs?
NO! Some are parasites and saprobes
Where is chlorophyll a and b located?
in chloroplasts
Are all plants multicellular?
Mostly
What are the 4 things plants need to survive?
- sunlight
- gas exchange
- water
- minerals
Why do plants need sunlight?
provides the energy needed for photosynthesis
Why do plants need gas exchange?
they need oxygen for cellular respiration and carbon dioxide as a raw ingredient for photosynthesis
Why do plants need water?
it is a raw ingredient for photosynthesis
PLANTS MUST EXCHANGE GASES WITH THE ATMOSPHERE AND THE SOIL WITHOUT LOSING EXCESSIVE AMOUNTS OF WATER THROUGH EVAPORATION
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What kind of plants can live in dry environments?
Plants that produce seeds
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What characteristics do gymnosperms share?
They produce naked seeds.
In alternation of generations spores will develop into the _________ and the gametes will develop into the ___________.
gametophyte stage
sporophyte stage
What adaptation helps plants retain water?
cuticle
What 4 important features divide the Plant kingdom into the five major groups?
- embryo formation
- specialized water-conducting tissues
- seeds
4, flowers
What is a diplod (2N) phase?
a sporophyte
What is a sporophyte?
a spore-making plant, the multicellular diploid phase
What is a haploid (N) phase?
a gametophyte
What is a gametophyte?
a gamete-making plant, the multicellular haploid phase
What do haploid (N) organisms carry?
a single set of chromosomes in their cell nuclei
What do diploid (2N) organisms carry?
two sets of chromosomes in their cell nuclei
What happens to chromosomes during fertilization?
chromosome number doubles, making a diploid cell from 2 haploid cells
N + N –> 2N
What happens to chromosomes during meiosis?
chromosome number is reduced by half, making 2 haploid cells from a diploid
2N –> N + N
What happens to chromosomes during mitosis?
chromosome number doesn’t change (mitosis is cell-copying!)
N –> N + N
2N –> 2N + 2N
What do all angiosperms produce?
fruit
What happens in phloem?
Food (carbohydrates) is transported down.
What stage of a plants life cycle produces sex cells (egg cells and sperm cells)?
gametophyte
What are some examples of devices to disperse seeds?
wind, water, large animals
What part of a woody stem forms rings that indicate the tree’s age?
xylem
Where does the energy that powers photosynthesis come from?
the sun
What are functions of the leaf’s veins (vascular tissue)? (3)
- to bring water to the leaf’s cells
- to connect the leaf with the rest of the plant
- to transport food to the rest of the plant
The oldest fossils of land plants are roughly how many years old?
50 million years old
What was the greatest challenge faced by early land plants?
obtaining water
How did early land plants obtain enough water?
they grew close to the ground in damp places
Why do biologists now classify green algae as plants?
they have cell walls, photosynthesis pigments, and reproductive cycles similar to plants as well as genomes
What are the 5 major groups of plants?
green algae bryophytes seedless vascular plants gymnosperms angiosperms
During what Period did large mats of green algae live?
the Cambrian Period, 550 million years ago
Give an example of a single-celled alga.
Chlamydomonas
The ______ of a green alga is able to survive freezing or drying conditions.
zygote
What is an example of a colonial green alga shaped like a filament?
spirogyra
What is an example of a colonial green alga that shows some cell specialization?
volvox
What is vascular tissue?
plant tissue that is specialized for carrying water and other minerals
What are the two main types of vascular tissue?
xylem and phloem
How are xylem and phloem similar? (2)
- the main cells are long and specialized to move fluids throughout the plant body
- make it possible for vascular plants to move fluids through their bodies against the force of gravity
What does xylem do?
carries water upward from the roots o every part of a plant
What does phloem do?
transports solutions of nutrients and carbohydrates produced by photosynthesis
What is the dominant stage in the life cycle of ferns (seedless vascular plant)?
the sporophyte
In which part of a pine tree are pollen grains produced?
pollen cones
Give an example of one entire male gametophyte of a gymnosperm.
a pollen grain
What is the name of the structures of gymnosperms in which the female gametophytes develop?
ovules
How long does the conifer life cycle typically take to complete?
2 years
In gymnosperm reproduction, what takes the place of water in the transfer of sperms to eggs?
pollen tubes
What are angiosperms?
seed plants that produce flowers and fruits
Flowering plants first appeared during what Period?
the Cretaceous Period
Where are the seeds of flowering plants encased?
in fruits
Which major group of angiosperms is by far the largest?
eudicots
Which plant’s discovery caused botanists to rearrange the classification of plants?
Amborella
What are annual angiosperms? Give some examples.
angiosperms that have a one year life span
ex. marigold, petunia, pansy, wheat
What are biennial angiosperms? Give some examples.
angiosperms that have a two year life span
ex. parsley, primrose, celery, foxglove
What are annual angiosperms? Give some examples.
angiosperms that live more than two years
ex. peonies, asparagus, grasses, palm trees, maple trees
What is an archegonium?
an egg-producing organ of seedless plants
What is xylem?
water-conducting vascular tissue
What is phloem?
sugar-conducting vascular tissue
What is a seed?
an embryo plant, food supply, and protective covering
What is pollination?
the transfer of pollen
What is an ovary?
an egg-containing structure of flowering plants
What is a dicot?
a plant with two seed leaves in seeds
What is an ovule?
a structure that a female gametophyte develops
What is an antheridium?
sperm-producing organ of seedless plants
What is a tracheophyte?
a plant with vascular tissues
What is a sporangium?
spore-producing structure of seedless plants
What are the three groups of bryophytes?
mosses, hornworts, liverworts
Why are bryophytes small?
they lack vascular tissue therefore they cannot draw up water higher than a meter off the ground due to the pull of gravity which limits bryophytes to damp environments
What is vascular tissue?
specialized tissue containing hardened lignin tubes that carry water throughout a plant
What is the dominant stage in the life cycle of green algae?
gametophyte
DESCRIBE THE GREEN ALGAE LIFE CYCLE
If conditions are unfavorable, Chlamydomonas produces gametes which fuse (fertilization) to create a sporophyte which will last until conditions become favorable. It will then grow and through meiosis create four flagellated haploid cells which can reproduce asexually (through mitosis).
What are the characteristics of green algae?
mostly aquatic, found in fresh and salt water, and in some moist areas on land
Why do green algae make direct contact with the water they grow in?
most green algae are single cells or branching filaments
they are able to absorb moisture and nutrients directly from their surroundings
What are the great moments in plant evolution in green algae? (4)
- first plants to evolve
- unicellular
- some started living in cooperative colonies
- first “phylum” in which true multicellularity evolved
What are the great moments in plant evolution in bryophytes? (3)
- waxy outer coating that resists drying out
- first plants to develop embryos
- started to evolve more specialized cells, tissues, organs
What are the great moments in plant evolution in seedless vascular plants? (2)
- first plants to evolve tallness
- vascular tissue provided structure and a method to deliver water and nutrients around a bigger, taller body
BRYOPHYTES AND SEEDLESS VASCULAR PLANTS CANNOT HAVE SEX WITHOUT WATER (SPERM MUST SWIM THROUGH WATER TO THE EGGS) SO THAT LIMITS WHERE THEY CAN LIVE
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What are the great moments in plant evolution in gymnosperms?
- pollen
- seeds
What is pollen?
males that can travel directly to females and then grow a pollen tube into the female to deliver sperm to egg without drying out
*allows sex on dry land!
What is archegonia?
where eggs are produced
What is antheirdia?
where sperm are produced
Which stage carries out the majority of photosynthesis?
gametophyte
What stage is dependent on what stage for its supply of water and minerals?
the sporophyte is dependent on gametophyte
What is the dominant stage in the life cycle of bryophytes?
gametophyte
BRYOPHYTE LIFE CYCLE: GAMETOPHYTE
gametes are formed in reproductive structures at the tips of the gametophytes, sperm and egg cells fuse together (fertilization) to create a DIPLOID ZYGOTE
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BRYOPHYTE LIFE CYCLE: SPOROPHYTE
the zygote is the beginning of the sporophyte life cycle, first it becomes a multicellular embryo within the gametophyte then eventually grows out of the body of the gametophyte and develop a SPORANGIUM
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What is a sporangium?
a long stalk with a capsule at the end
What are tracheids?
special water-conduction cells
What is the dominant stage in the life cycle of seedless vascular plants?
sporophyte, but the gametophyte plant is usually pretty independent and can photosynthesize on its own
Why don’t seed plants require water for reproduction?
because of:
- a reproductive process that takes place in cones and flowers
- the transfer of sperm by pollination
- the protection of embryos in seeds
Where do gametophytes exist in gymnosperms?
cones
What are flowers?
reproductive organs that are composed of four different kinds of specialized leaves: sepals, petals, stamens, and carpels
Where do gametophytes exist in angiosperms?
flowers
Where is a pollen grain formed?
inside a cone or flower
What does a pollen grain contain?
the entire male gametophyte plant which will form the sperm, the pollen allows the sperm to avoid drying out
What does the seed coat do?
protects the embryo from drying out
What is the dominant stage in the life cycle of gymnosperms?
sporophyte
MALE GAMETOPHYTES
multicellular but very small are are totally inside the pollen grain, made by meiosis in POLLEN CONES
FEMALE GAMETOPHYTES
multicellular, and small, made by meiosis inside the OVULES of SEED CONES
What does polintation allow?
it allows fertilization to take place without the need for gametes to swim through water
DEVELOPMENT INSIDE SEEDS
if a pollen grain lands near an ovule, it grows a pollen tube which contains 2 sperm nuclei. When the pollen tube gets to the female gametophyte, one sperm nucleus fertilizes the egg. This results in a diploid zygote which will groq into an embryo, the new sporophyte plant. A seed coat forms around the embryo to protect it. The seeds of gymnosperms are usually scattered by wind and sometimes by animals.
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What are the advantages of flowers? (2)
- often, animals are attached to the flowers and unknowingly transfer pollen from one flower to another
- more likely for males (pollen) to get into females (embryo sacs) of the same species
What are the advantages of fruits?
-mutant ovaries that cause seeds (babies) to be dispersed away from original plant, which reduced competition for itself
Angiosperm Classification
old categories (taxa) are currently being updated
Are all angiosperm vascular?
Yes
What are cotyledons?
seed leaves
What are monocots?
flowering plants with one seed leaf
What are dicots?
flowering plants with two seed leaves
What are the 5 major clades of angiosperms?
Amborella Water Lily Magnoliids Monocots Eudicots
How are different angiosperms categorized?
grouped according to the number of their seed leaves, the strength and composition of their stems, and the number of growing seasons they live
CHARACTERISTICS OF MONOCOTS
SEEDS: single cotyledon
LEAVES: parallel veins
FLOWERS: floral parts often in multiples of 3
STEMS: vascular bundles scattered throughout stem
ROOTS: fibrous roots
CHARACTERISTICS OF DICOTS
SEEDS: two cotyledons
LEAVES: branched veins
FLOWERS: floral parts often in multiples of 4 or 5
STEMS: vascular bundles arranged in a ring
ROOTS: taproot
What are Woody plants?
made primarily of cells with thick cell walls that support the plant body
What are herbaceous plants?
smooth and non-woody plants that do not produce wood as they grow
What are stamens?
the male parts of the flower that consists of a stalk called a filament with an anther at its tip
What are anthers?
the structures in which pollen grains (male gametophytes) are produced
What do carpels do?
produce and shelter the female gametophyte and later, seeds
What is a carpel?
has a broad base forming an ovary, which contains one or more ovules where female gametophytes are produced
What is a stigma?
a sticky or feathery portion at the top of the style
What is the style?
a stalk of the carpel
What is a pistil?
a single carpel or several fused carpels
What is the stigma specialized in?
capturing pollen
How does fertilization in angiosperm differ from fertilization in other plants?
two fertilizations take place, one produces the zygote and the other produces a tissue called endosperm within the seed
