BIOL 1407 Review Sheet Plants
1) All plants have apical meristems . These are regions of cells that divide producing longitudinal growth.
This allows the plant structures (roots, stems, leaves, etc.) to elongate ( primary growth ). Increasing the girth of a structure is called secondary growth . p576
2) All plants have multicellular, diploid embryos that are protected and nourished within tissues produced by the parents (e.g. the seed in gymnosperms and angiosperms, the archegonium in mosses and ferns). For this reason plants (in contrast to green algae, etc.) are refered to as embryophytes . p577
3) All plants have alternation of generation . The two alternating generations are called sporophyte (2N) and gametophyte (1N). The more primitive condition is to have a dominant gametophyte (this is the case in most green algae and bryophytes). p576
4) The general life cycle is as follows (terms in italics are the process that produces the following stage): sporophyte
 meiosis

spores
 mitosis

gametophyte
 mitosis

gametes
 fertilization
 zygote
 mitosis

sporophyte.
5) Mitosis: 1N

1N or 2N

2N
6) Meiosis: 2N

1N
7) Fertilization: 1N

2N
8) Spores are produced by meiosis in the sporangia , organs of the sporophyte. In mosses, the sporangia is found in the capsule. In ferns, the sporangia are called sori and are found in the undersides of the leaves.
In gymnosperms, the male and female cones are the sporangia. In angiosperms, the male and female parts of the flower are the sporangia. Spores are produced from 2N cells in the sporangia. p577
9) Gymnosperms and angiosperms are heterosporous . This means that there are distinct male and female spores that are produced by separate male and female sporangia. The spore that generates the female gametophyte is called the megaspore . The spore that generates the male gametophyte is called the microspore . p592
10) Seedless plants are homosporous . All of their spores are produced from a single type of sporangium. p586
11) Gametes are produced by mitosis from gametangia , organs of the gametophyte. All plants have an egg producing gametangia called an archegonium (female) and a sperm producing gametangia called an antheridium (male). p577
12) General differences in major plant groups (general overview of ch 29 and 30):
Group Gametophyte dominant?
Vascular tissue ?
Seeds ? Flowers
Fruits ? and Pollination
Yes Usually no
No No No pollen
(homosporous)
Bryophytes
(mosses, liverworts, etc.)
Pteridophytes
(seedless vascular plants)
(e.g. Ferns )
No Yes No No No pollen
(homosporous)
Gymnosperms No
Angiosperms No
Yes
Yes
Yes
Yes
No
Yes
Wind only
Animals or wind
13) In seedless plants (bryophytes and ferns) sperm are released from the antheridium and swim through environmental water to the archegonium. p580-1, 584-5 In seed plants, sperm are carried to the female reproductive organ (cone or pistil) by pollen (the male gametophyte). The pollen grain grows a pollen tube to the archegonium, and the sperm swims through the tube to the egg. p592-7, p599-600
14) Review the moss life cycle from figure 29.8.
15) Review the fern life cycle from fig 29.12. Note in particular the similarities and the differences with the moss life cycle. What is a prothallus ?
16) Review the life cycles of the seed plants: gymnosperm and angiosperm in fig. 30.6 and 30.10. One of the main differences bewtween seedless plants and seed plants is that seeds plant spores are not dispersed before developing into gametophytes, but instead develop into gametophytes within the sporangia.
17) To avoid offspring growing on top of parents, dispersal is necessary at some point in the plant life cycle. Seedless plants (mosses and ferns) disperse spores. p580-1, p585-6 Seed plants disperse seeds. p593-600

18) The two largest groups of angiosperms are dicots (sometimes called eudicots) and monocots .
Monocots include grasses, grains like corn and wheat, lilies, irises, bamboo, palm trees, and orchids. Most other angiosperms are dicots. p602-3
Monocots
# of cotyledons Leaf veins
1 Parallel
Stem vascular bundles
Complex arrangement
Usual # of flower parts
Multiple of 3
Roots
Fibrous
Dicots 2 Branched Arranged in a ring
Multiple of 4 or 5
Taproot
19) Plants have two main body parts: shoot system and root system . Shoots are stems, leaves and flowers.
Roots are usually underground, and function to absorb water and inorganic nutrient. Roots also may function in storage. p713-4
20) Plants have three tissue systems: epidermal tissue (covers and protects all plant parts except woody stems); vascular tissue (xylem and phloem; transport water, sugar, nutrients, and provide support); and ground tissue (fills in the spaces between vascular and epidermal tissue; support; storage; photosynthesis). p717
21) Plant epidermal tissues secrete a waxy cuticle to seal their aboveground parts against drying. Vascular plants have stomata on their leaf surfaces which may open or close to control the evaporation of water out of the leaf. Stomata are lined by two guard cells . When the guard cells are swelled with water they buckle apart and the stomata opens. When the guard cells have low water pressure, the guard cells seal together. p724-5
22) Phloem transports sugar made by photosynthesis as sugary sap. Xylem transports water and minerals.
Mature xylem is made of dead cells that form long tubes made of cell walls. p717,719 Water is transported to high parts of the plant via evaporative transpiration . Xylem tubes extend from the roots all the way up until they open near the stomata. When water evaporates from the stomata, a vacuum is created. This vacuum draws water up from the xylem, creating a negative pressure that draws moisture from the soil into the roots. p746-50
23) Know how a woody stem develops from a herbaceous stem. See fig 35.18, 35.19, 35.20. Know how vascular cambium produces both xylem and phloem. What happens to a year’s secondary growth of xylem when a new growth of secondary xylem is produced? What happens to the old secondary phloem when new phloem is produced? What is the difference between heartwood and sapwood ? What happens to epidermal and ground tissue (e.g. the pith) when a herbaceous stem develops into a woody stem? p725-8
24) A unique and very important adaptation in angiosperms is animal pollination . Some angiosperms are pollinated by wind, like gymnosperms. But most angiosperm pollen is carried to a female stigma by a particular kind of animal. p604
25) Some plants (e.g. legumes like clover or soybean) form mutualistic , symbiotic relationships with cyanobacteria living in root nodules . What nutrient does cyanobacteria make available for the plant? p764-6
26) Plants produce compounds other than carbohydrates, fats, or proteins called secondary compounds .
Many of these are of practical use. See table 30.1. p605