In the plant life cycle, the multicellular stage whose cells are all haploid is called the
Gametophyte
✓
Sporophyte
Zygote
Sporocyte
Correct Answer
Gametophyte
The gametophyte is the haploid multicellular generation; it grows from a spore and makes gametes. The sporophyte is the diploid multicellular generation. A zygote is a single diploid cell formed at fertilization. A sporocyte is a diploid mother cell that divides to make spores.
Category: Plant Life Cycles
Question 2
Inside a sporangium, diploid sporocytes produce haploid spores by which process?
Mitosis
Meiosis
✓
Fertilization
Binary fission
Correct Answer
Meiosis
Meiosis halves the chromosome number, so diploid sporocytes give rise to haploid spores. Mitosis keeps the chromosome number the same and is how a gametophyte makes gametes. Fertilization joins two haploid gametes into a diploid zygote. Binary fission is the division process of prokaryotes.
Category: Plant Life Cycles
Question 3
In seedless plants, which structure holds the egg and later the young embryo as it develops?
Antheridium
Strobilus
Archegonium
✓
Rhizoid
Correct Answer
Archegonium
The archegonium is the female gametangium; the egg is fertilized inside it, and the new sporophyte begins its growth there. The antheridium is the male gametangium that releases sperm. A strobilus is a cone-like cluster of spore-bearing leaves. A rhizoid is a thin anchoring filament of a bryophyte.
Category: Plant Life Cycles
Question 4
Growth in length at the tips of plant shoots and roots comes from which tissue?
Lateral meristems
Guard cells
Root cap cells
Apical meristems
✓
Correct Answer
Apical meristems
Apical meristems are caps of dividing, undifferentiated cells at shoot and root tips that keep adding new cells throughout the plant's life. Lateral meristems increase the thickness of stems and trunks rather than their length. Guard cells surround stomata and control their opening. Root cap cells protect the tip of a growing root but do not produce the root's new tissues.
Category: Land Adaptations
Question 5
Which waxy coating on leaves and stems helps land plants limit water loss?
Cuticle
✓
Stomata
Phloem
Pollen
Correct Answer
Cuticle
The cuticle is a waterproof layer of wax on the outer surfaces of a plant that slows drying out. Stomata are pores that open and close to exchange gases, and water escapes through them. Phloem is the tissue that carries sugars. Pollen is the male gametophyte of seed plants.
Category: Land Adaptations
Question 6
Which tough polymer in the cell walls of vascular plants, generally absent in bryophytes, helped plants grow tall?
Cellulose
Lignin
✓
Starch
Keratin
Correct Answer
Lignin
Lignin stiffens the cell walls of vascular tissue, giving the support that allowed plants to grow upright and tall. Cellulose is present in the cell walls of all plants, including bryophytes. Starch is a storage carbohydrate, not a structural wall polymer. Keratin is an animal protein found in hair and nails.
Category: Land Adaptations
Question 7
In a moss, which generation is the green, leafy plant that is easy to see?
The diploid sporophyte
The triploid endosperm
The haploid gametophyte
✓
The haploid pollen grain
Correct Answer
The haploid gametophyte
Bryophytes such as mosses are the only land plants in which the haploid gametophyte is the dominant, conspicuous generation. The diploid sporophyte of a moss is a small stalk and capsule that grows from the gametophyte. The triploid endosperm is a food tissue found only in flowering plant seeds. The haploid pollen grain is the male gametophyte of seed plants, and mosses do not make pollen.
Category: Bryophytes
Question 8
Which of these plants is a bryophyte rather than a vascular plant?
Club mosses
Horsetails
Whisk ferns
Liverworts
✓
Correct Answer
Liverworts
Liverworts are bryophytes, nonvascular land plants that lack true xylem and phloem, along with mosses and hornworts. Club mosses are lycophytes with vascular tissue and, despite their name, are not true mosses. Horsetails are seedless vascular plants with jointed stems. Whisk ferns are seedless vascular plants closely related to ferns.
Category: Bryophytes
Question 9
Which bryophytes are recognized by a long, narrow, pipe-like sporophyte that keeps growing throughout the plant's life?
Hornworts
✓
Liverworts
Mosses
Whisk ferns
Correct Answer
Hornworts
Hornworts get their name from their horn-shaped sporophytes, which rise from a small blue-green gametophyte and continue to lengthen. Liverworts are bryophytes known for flat, lobed gametophytes in some species. Mosses have a sporophyte that ends in a capsule on a short stalk. Whisk ferns are seedless vascular plants, not bryophytes.
Category: Bryophytes
Question 10
Mosses are useful for monitoring air quality because they are
Covered by a thick waxy cuticle
Highly sensitive to air pollution
✓
Dependent on insects for pollination
Anchored by deep, branching roots
Correct Answer
Highly sensitive to air pollution
Mosses are sensitive to air pollution, so their decline signals poor air quality; copper salts that harm them are even used in moss-killing products. Covered by a thick waxy cuticle is wrong, because mosses have little protection from their surroundings. Dependent on insects for pollination is wrong, because mosses make no pollen. Anchored by deep, branching roots is wrong, because mosses have only shallow rhizoids.
Category: Bryophytes
Question 11
Small leaves with a single vein, called microphylls, are characteristic of which plants?
Ferns
Cycads
Club mosses
✓
Flowering plants
Correct Answer
Club mosses
Club mosses (lycophytes) bear microphylls, small leaves each supplied by a single unbranched vein. Ferns have large leaves with branching veins. Cycads have large compound leaves that resemble palm fronds. Flowering plants have leaves with branched networks or many parallel veins.
Category: Seedless Vascular Plants
Question 12
Coal deposits formed from vast swamp forests of tree-sized seedless vascular plants gave its name to which geologic period?
Cretaceous
Cambrian
Jurassic
Carboniferous
✓
Correct Answer
Carboniferous
During the Carboniferous, roughly 359 to 299 million years ago, swamp forests of giant club mosses and horsetails were buried and slowly turned into coal, giving the period its name. The Cretaceous is the last period of the Mesozoic, when flowering plants spread widely. The Cambrian is known for the rapid diversification of marine animals. The Jurassic is the middle period of the Mesozoic, the age of dinosaurs and gymnosperms.
Category: Seedless Vascular Plants
Question 13
The name gymnosperm comes from Greek words meaning
Naked seed
✓
Vessel seed
Winged seed
Many seeds
Correct Answer
Naked seed
Gymnosperm means naked seed, because the seeds of these plants are not enclosed in an ovary, often sitting exposed on cone scales. Vessel seed is the meaning of angiosperm, whose seeds are enclosed. Winged seed describes the shape of some seeds, not the name of the group. Many seeds is not the meaning of the word.
Category: Gymnosperms
Question 14
A pine seed contains tissues from three generations. Which tissue serves as the seed's food supply for the embryo?
The seed coat
The female gametophyte
✓
The pollen tube
The embryo's root
Correct Answer
The female gametophyte
In a pine seed, the haploid female gametophyte surrounds the embryo and provides its nourishment. The seed coat comes from the parent sporophyte and protects the seed. The pollen tube only delivers sperm to the egg and does not remain as stored food. The embryo's root is part of the young plant itself, not its food reserve.
Category: Gymnosperms
Question 15
Which gymnosperms have large compound leaves that make them look like palms and are sometimes pollinated by beetles?
Conifers
Gnetophytes
Cycads
✓
Ginkgoes
Correct Answer
Cycads
Cycads have stout trunks crowned by large compound leaves, which often get them mistaken for palms, and some rely on beetles rather than wind for pollination. Conifers have needle-like or scale-like leaves. Gnetophytes include vines, desert plants, and shrubs such as Ephedra. Ginkgoes have fan-shaped leaves.
Category: Gymnosperms
Question 16
Needle-shaped leaves help conifers survive in cold, dry climates by
Attracting animal pollinators
Producing sugary nectar in winter
Absorbing water directly from snow
Reducing water loss and shedding snow
✓
Correct Answer
Reducing water loss and shedding snow
Thin needles expose little surface to drying air, which limits water loss, and their shape lets snow slide off before it breaks branches. Attracting animal pollinators is wrong because conifers are wind-pollinated. Producing sugary nectar in winter is not something conifers do. Absorbing water directly from snow is not a function of needles.
Category: Gymnosperms
Question 17
The sticky tip of a flower's carpel, where pollen grains land, is the
Stigma
✓
Style
Anther
Filament
Correct Answer
Stigma
The stigma is the receptive tip of the carpel that captures pollen. The style is the slender stalk connecting the stigma to the ovary. The anther is the part of the stamen that makes pollen. The filament is the stalk that holds up the anther.
Category: Angiosperms
Question 18
After fertilization in a flowering plant, the ovary develops into the
Seed
Fruit
✓
Endosperm
Embryo sac
Correct Answer
Fruit
A fruit is a mature ovary, formed as the ovary wall thickens around the developing seeds. A seed develops from an ovule inside the ovary, not from the ovary itself. Endosperm is the food tissue inside a seed. The embryo sac is the female gametophyte inside the ovule.
Category: Angiosperms
Question 19
In double fertilization, one sperm fertilizes the egg while the second sperm fuses with two polar nuclei to form the
Diploid zygote
Haploid embryo sac
Triploid endosperm
✓
Diploid seed coat
Correct Answer
Triploid endosperm
The second sperm joins the two polar nuclei, producing triploid (3n) endosperm that stores food for the embryo. The diploid zygote comes from the other sperm fusing with the egg. The haploid embryo sac is the female gametophyte that existed before fertilization. The diploid seed coat develops from the parent's ovule tissues, not from a sperm.
Category: Angiosperms
Question 20
Which feature is typical of monocots?
Two cotyledons in each seed
Leaves with netlike veins
Vascular bundles arranged in a ring
Flower parts in multiples of three
✓
Correct Answer
Flower parts in multiples of three
Monocots, such as lilies and grasses, usually have flower parts in threes or multiples of three. Two cotyledons in each seed is a eudicot trait. Leaves with netlike veins are typical of eudicots, while monocots have parallel veins. Vascular bundles arranged in a ring describe eudicot stems, while monocot bundles are scattered.
Category: Angiosperms