Bio 1 - Rat3

Front 1

What are Charophyceas?

Back 1

Green algae; closest relatives of land plants.

Front 2

What is alternation of generations?

Back 2

Life cycle:

Sporophytes (2n) > meiosis > spore (n) > mitosis > gametophytes (n)

Front 3

What is apical meristem?

Back 3

Localized regions of cell division at the tips of shoots and roots.

Cells produced by apical meristems differentiate into various tissues, including a surface epidermis that protects the body and several types of internal tissues.

Front 4

What are spores?

Back 4

Spores are reproductive cells that can develop into a new organism without fusing with another cell.

Haploid spores are produced via meiosis in a mature sporophyte.

Front 5

What are sporangia?

Back 5

- The sporophyte has multicellular organs called sporangia.
- Produces plant spores.

Multicellular sporangia that produce spores with sporopollenin-enriched walls are key terrestrial adaptations of land plants.

Although charophyceans produce spores, these algae lack multicellular sporangia and their flagellated, water-dispersed spores lack sporopollenin.

Front 6

What are sporocytes?

Back 6

Within sporangia, diploid cells called sporocytes, also known as spore mother cells, undergo meiosis and generate the haploid spores.

Front 7

What are gametangia?

Back 7

• Distinguishes early land plants from their algael ancestors
• Multi-cellular organ that produces gametes

Front 8

What are archegonia?

Back 8

Female gametangia are called archegonia, each of which is a vase-shaped organ that produces a single egg retained within the base of the organ.

Front 9

What are anteridium?

Back 9

Male gametangia called anteridia produce and release sperm into the environment.

Front 10

What are embryophytes?

Back 10

The multicellular, dependent embryo of land plants is such a significant derived trait that land plants are also know as embryophytes.

Front 11

What are vascular tissues?

Back 11

Cells joined into tubes that transport water and nutrients throughout the plant body.

Front 12

What are vascular plants?

Back 12

Most plants have a complex vascular tissue system and are thereofore called vascular plants.

Front 13

What are Bryophytes?

Back 13

Nonvascular plants are often informally called bryophytes (bryo, moss and phyton, plant). Nonvascular plants are plants that do not have an extensive transport system. Examples include liverworts, hornworts and mosses.

Front 14

What are Gymnosperms?

Back 14

A seed is an embryo packaged with a supply of nutrients inside a protective coat. Seed plants can be divided into two groups, gymnosperms or angiosperms, based on the absence or presence of enclosed chambers in which seeds mature.

Gymnosperm are grouped together as “naked seed” plants because their seeds are not enclosed in chambers.

Front 15

Angiosperm

Back 15

Angiosperm seeds develop inside chambers called ovaries which originate within flowers and mature into fruits. Consists of all flowering plants.

Front 16

What are Gametophytes? p576

Back 16

The cells of gametophyte are haploid, meaning they have a single set of chromosomes. The gametophyte is named for its production by mitosis of haploid gametes - eggs and sperm - that fuse during fertilization, forming diploid zygotes.

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Sporophyte p576

Back 17

Mitotic division of the zygote produces the multicellular sporophyte, the spore-producing generation. Thus, the cells of the sporophyte are diploid, having two sets of chromosomes – one from each gamete.

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Stomata p581

Back 18

Both hornwort and moss sporophytes also have specialized pores called stomata which are also found in all vascular plants.
These pores support photosynthesis by allowing the exchange of CO2 and O2 between outside air and the sporophyte interior.
Stomata are the main avenues by which water evaporates from the sporophyte. In hot, dry conditions, the stomata can close to minimize water loss.

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Seedless vascular plant p578

Back 19

Vascular plants that lacks seeds. However, notice in figure 29.7 that seedless vascular plants are not monophyletic. Fern and moss is an example.

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Pollen grain

Back 20

Microspores develop into pollen grains, which contain the male gametophytes of seed plants. Protected by a tough coat containing the polymer sporopollenin, pollen grains can be carried away from their parent plant by wind or by hitchhiking on the body of an animal that visits the plant to feed.

Front 21

Pollination

Back 21

The transfer of pollen to the part of a seed plant containing the ovules is called pollination. If a pollen grain germinates, it gives rise to a pollen tube that discharges two sperm into the female gametophyte within the ovules, as shown in Figure 30.3b

Front 22

Seed

Back 22

If a sperm fertilizes an egg of a seed plant, the zygote grows into a sporophyte embryo. The whole ovule develops into a seed, which consists of the embryo, along with a food supply, packed within a protective coat derived from the integuments.

Front 23

Flower p598

Back 23

The flower is an angiosperm structure specialized for sexual reproduction. In many angiosperm species, insects or other animals transfer pollen from one flower to the female sex organs on another flower, which makes pollination more directed than the wind-dependent pollination of most gymnosperms.

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Fruit p598

Back 24

A fruit typically consists of mature ovary, although it can include other flower parts as well. As seeds develop from ovules after fertilization, the wall of the ovary thickens. A pea pod is an example of a fruit, with seeds (mature ovules, the peas) encased in the ripened ovary (the pod). Fruits protect dormant seeds and aid in their dispersal.

Front 25

Monocot p602

Back 25

Until the late 1990s, most systematic divided flowering plants into two groups based partly on the number of cotyledons, or seed leaves, in the embryo. Species with one cotyledon were called monocots.
Other features, such as flower and leaf structure were also used to define the two groups. For example, monocots typically have parallel leaf veins (think of a grass blade).
Some examples of monocots are orchids, palms and grain crops such as maize, wheat and rice.

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Dicot p602

Back 26

Species with two cotyledon were called dicots.
Veins of most dicots have a netlike pattern.
Examples of dicots are roses, peas, sunflowers and maples.

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Hyphae p609

Back 27

The bodies of these fungi typically form a network of tiny filaments called hyphae. Hyphae are composed of tubular cell walls surrounding the plasma membrane and cytoplasm of the cells.

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Chitin p609

Back 28

Unlike the cellulose walls of plants, fungal cell walls contain chitin, a strong but flexible nitrogen-containing polysaccharide that is also found in the external skeletons of insects and other arthropods.

Front 29

Mycelium p609

Back 29

Fungal hyphae form an interwoven mass called a mycelium that surrounds and infiltrates the material on which the fungus feeds. The structure of a mycelium maximizes the ratio of its surface area to its volume, making feeding more efficient.

Front 30

Mychorrihizae p610

Back 30

Some fungi have specialized hyphae that allow them to feed on living animals. Other specials have specialized hyphae called hautoria that enable them to penetrate the tissue if their hosts. Mutually benefital relationships between such fungi and plant roots are called mychorrihizae.
Mychorrihizae fungi can deliver phosphate ions and other minerals to plants, which the plants themselves cannot acquire on their own. In exchange, the plants supply the fungi with organic nutrients.

Front 31

Lichen p621

Back 31

Lichens are a symbiotic association of millions of photosynthetic micro-organisms held in a mass of fungal hyphae. They form a surface-hugging carpet that can be found growing on rocks, rotting logs, trees and roofs in various shrub-like, leaf-like, or encrusting forms.
The photosynthetic partners are typically unicellular or filamentous green algae or cyanobacteria. The fungal component is most often an ascomycete, but several basidiomycete lichens are known. The fungus usually gives a lichen its overall shape and structure, and tissues formed by hyphae account for most of the lichen’s mass.

Front 32

Blade

Back 32

The leaf is the main photosynthetic organ of the most vascular plants, although green stems also perform photosynthesis. Leaves vary extensively in form but generally consist of a flattened blade and a stalk, the petiole, which joins the leaf to a node of the stem.

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Petiole p720

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The stalk of a leaf.

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Primary growth

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Plants are capable of indeterminate growth because they have perpetually embryonic tissue called meristems. There are two main types: apical merstems and lateral meristems.
Apical meristems, located at the tips of roots and in the buds of shoots, provide additional cells that enable the plant to grow in length, a process known as primary grow.
Primary grow allows roots to entend throughout the soil and shoots to increase exposure to light and CO2.
In herbaceous (nonwoody) plants, primary growth produces all, or almost all, of the plant body..

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Secondary growth p720

Back 35

Woody plants, however grow in girth in all parts of stems and roots where primary growth has ceased. This growth in thickness, known as secondary growth, is caused by the activity of lateral meristems called the vascular cambium and cork cambium. These cylinders of dividing cells extend along the length of roots and stems.

Front 36

Tropism p792

Back 36

The concept of chemical messengers in plants emerged from a series of classic experiments on how stems respond to light. The shoot of a houseplant on a windowsill grows toward light.
If you rotate the plant, it soon reorients its growth until its leaves again face the window. Any growth response that results in curvatures of whole plant organs toward or away from stimuli is called tropism.

Front 37

Phototropism p792

Back 37

The growth of a shoot toward light is called positive phototropism, whereas growth away from light is negative phototropism.

Front 38

Gravitropism p809

Back 38

Place a plant on its side and it adjusts its growth so that the shoot bends upward and the root curves downward. In their response to gravity, or gravitropism, roots display positive gravitropism and shoots exhibit negative gravitropism.

Front 39

What are the algal ancestors of land plants?

Back 39

Researchers have identified green algae called charophyceans as the closest relatives of land plants.

Front 40

What are 5 key traits present in nearly all land plants but absent in charophycean?

Back 40

- Apical meristems
- Alternation of Generations
- Land plants have walled spores.
- Multicellular Gamatangia
- Dependent embryos

Front 41

What are secondary compounds, why do plants make them, and what are some of the things that humans use them for? P575

Back 41

They are products of secondary metabolic pathways.

Secondary compounds include alkaloids, terpenes, tannins and phenolics such as flavonoids.

For humans, it fights malaria.

For plants it:
- helps defend against herbivores and parasites
- Absorbs UV radiation
- may acts as signals in symbiotic relationships with beneficial soil microbes

Front 42

The life cycle of mosses and other bryophytes is dominated by what stage? Gametophyte or sporophyte? p580

Back 42

Gametophyte

Front 43

The life cycle of gymnosperms is dominated by what stage? Gametophyte or sporophyte?

Back 43

dunno

Front 44

The life cycle of angiosperms is dominated by what stage? Gametophyte or sporophyte?

Back 44

dunno

Front 45

What are some advantages of having a reduced gametophyte generation?

Back 45

Allowed for important evolutionary innovation in seed plants:

- Their tiny gametophytes can develop from spores retained within the sporangia of the parental sporophyte. This arrangement protects the delicate female (egg-containing) gametophytes from environmental stresses.

- Also enables the dependent gametophyte to obtain nutrients from the sporophyte. In contrast, free living gametophytes of seedless plants must fend for themselves.

Front 46

What is the function of each of Xylem?

Back 46

Conducts most of the water and minerals.

Front 47

What is the function of each of phloem?

Back 47

Distribute sugars, amino acids, and other organic products.

Front 48

What are the functions of roots?

Back 48

Anchor vascular plants and enable them to absorb water and nutrients from the soil. Also allow the shoot system to grow taller.

Front 49

What is the function of each of leaves?

Back 49

Increase the surface area of vascular plants, thereby capturing more solar energy for photosynthesis.

Front 50

Are fungi autotrophs or heterotrophs?

Back 50

heterotrophs

Front 51

Do fungi ingest food?

Back 51

no

Front 52

Are fungi more closely related to plants or animals?

Back 52

Animals

Front 53

Why are nitrogen fixing bacteria important to plants?

Back 53

Provide some plant species with a built-in source of fixed nitrogen for assimilation into organic compounds. For example, rhizobium bacteria can fix atmosphere N2 and supply it as ammonium, a form readily used by the plant.

Front 54

How do plants defend themselves against herbivores? What are physical defenses? What are chemical defenses?

Back 54

Plants counter excessive herbivory with both physical defenses, such as thorns and chemical defenses, such as the production of distasteful or toxic compounds.

Front 55

What are cotyledon?

Back 55

Seed leaves