Exam 3

Question 1

What made plants move onto land?

Answer 1

Combination of new opportunities available on land, such as unfiltered sunlight, more CO2 available, more nutrients, and few herbivores and pathogens on land.

Question 2

What were some challenges of new land plants?

Answer 2

There was less water on land, and gravity caused plants difficulty.

Question 3

what were adaptations which caused charophytes to move to land?

Answer 3

-charophytes already lived in shallow freshwater ponds, so a somewhat similar environment to land.

-charophytes contain sporopollenin, which is a durable polymer which prevents charophyte zygotes from drying out.

Question 4

What are shared features of charophytes and land plants?

Answer 4

Both contain rings of cellulose synthesizing proteins, which are rings in the plasma membrane which produce cellulose in the cell wall. They both have a similar structure of flagellated sperm, and contain sporopollenin.

Question 5

what are some innovations of land plants, in NO DETAIL?

Answer 5

alternation of generations, multicellular dependent embryos, sporangia, sporopollenin, waxy cuticle, and apical meristems.

Question 6

What plants have alternation of generations

Answer 6

Plants are multicellular haploid and diploid organisms. They are not present in charophytes, but they are present in some algae.

Question 7

what is the difference between charophytes and chlorophytes?

Answer 7

Chlorophytes are mostly freshwater plants, can be multicellular or unicellular, have two flagella, and use both types of reproduction. They have over 7500 species.

Charophytes are algae most closely related to land plants. They have shared traits with land plants and are important in plant evolution.

Question 8

How are multicellular, dependent embryos an innovation of plants?

Answer 8

the embryos are retained within a gametophyte.

Question 9

explain sporangia

Answer 9

Sporangia is an enclosure found in sporophytes. They are multicellular organ which produce haploid spores.

Question 10

what are gametophytes

Answer 10

gametophyte is stage in the life cycle of plants and algae that undergo alternation of generations. It is a haploid multicellular organism that develops from a haploid spore that has one set of chromosomes

Question 11

what is sporopollenin

Answer 11

sporopollenin is a substance present in spores which protects against harsh conditions, especially desiccation (drying out)

Question 12

what is the waxy cuticle

Answer 12

a waxy cuticle is the covering of wax and other polymers. It protects plants from drying out and protects against bacterial infections.

Question 13

what are apical meristems

Answer 13

apical meristems are regions at the tips of plant roots and shoots which experience cell division. Cell division in these regions is continuous during a plants life, and increase ability to obtain resources.

Question 14

what are some facts about early land plants?

Answer 14

-fossil evidence shows that plants were on land 470 mya.

-spores and tissue fossils have been extracted from 450 mya rock

-large plant structures appeared in fossil record 425 mya

-by 400 mya, many diverse plants lived on land

Question 15

unique traits of early land plants

Answer 15

-specialized tissues for water transport
-stomata
-branched sporophytes
-lacked true roots and leaves

Question 16

what are sporophytes

Answer 16

the diploid, multicellular, spore producing phase in plant and algae.

Question 17

what are nuclearids?

Answer 17

organisms which are most closely related to fungi. Most consume algae or cyanobacteria. They live in soils and freshwater habitats.

Question 18

what are fungi?

Answer 18

fungi are a large group of organisms which have over 100k organisms described, with an estimated 1.5 million left to describe. They can be found all over the world in diverse habitats, including marine, terrestrial, and freshwater.

Question 19

importance of fungi

Answer 19

-help with ecosystem function and health
-agriculture
-food industry
-medicine
-culture

Question 20

characteristics of fungi

Answer 20

-reproduce both ways
-contain no chloroplasts
-have cell walls and vacuoles
-contain chitin in cell wall (besides fungi, only arthropods contain chitin)
-every group except chytrias have lost the posterior flagellum

Question 21

fungal nutrition

Answer 21

-fungi are heterotrophs. They break down nutrients and recycle nutrients

-produce hydrolytic enzymes (enzymes which break down molecules from the environment into simpler forms)

-the fungi then absorb these simpler molecules

-fungi can be decomposers, parasites, and mutualists

Question 22

fungi morphology

Answer 22

yeast- single cell form of fungi, less than 1% have this form

filament- multicellular, most fungi grow as filaments and yeast

hypha (p. hyphae)- tubular, cylindrical, thread-like filament. 2-10 um in diameter, and grows at tips and bifurcations (branching)

mycelium (p. mycelia)- fuzzy mold. Networks of hyphae which result from apical and branching growth. Increase the surface area for absorption.

spore producing structures- have variety and diversity. Some are mycelial structures, and use both types of reproduction. spores are haploid.

specialized hyphae

Question 23

what are specialized hyphae

Answer 23

haustorium. Haustorium can be a parasitic or mutualistic structure at the tips of hyphae. Hyphae break down the host cell wall and the haustorium develop adjacent to the plasma membrane. They DO NOT kill the host

Question 24

Where is haustorium observed?

Answer 24

Haustorium is observed in Mycorrhiza (p. mycorrhizae). There is a beneficial association (mutualism) between plant roots and the fungus.

This is a mutual relationship because the fungus gives the plant phosphate ions and minerals, and the plant gives the fungi carbs and other organic nutrients.

lichen- beneficial association between algae and fungus

endophytes- beneficial association between plants and fungi

Question 25

importance of mycorrhizae

Answer 25

the plant's absorption of water and minerals increases. Mycelium has a large surface area. a higher root ratio improves the plant's absorption abilities.

Question 26

basic fungal lifecycle for asexual fungi

Answer 26

hyphae develop into spore-producing structures. Fungi and spores are haploid. molds- these are conidiophores. conidium (spore) producing structures on the ends of the hyphae yeasts- use budding and cell division to replicate. Use DNA replication.

Question 27

basic fungal lifecycle for sexual fungi

Answer 27

haploid hyphae from two different myceliae find each other. They use pheremondes, and there are both positive and negative mating types. the myceliae fuse through plasmogamy. Cytoplasms fuse but the nuclei don't fuse. Both are haploid. (n+n) heterokaryotic stage- mycelium contain different nuclei (from n+n) dikaryotic stage- the pair of nuclei each from different parent move into the cell, but they do not fuse (n +n). -ascomycota and basidiomycota karyogamy- haploid nuclei fuse to become a diploid nuclei (2n). they zygote is transient. spores- meiosis of zygote, haploid (n)

Question 28

types of fungi

Answer 28

microsporidia, chytrids, zygomycetes, Glomeromycetes, ascomycetes, basidomycetes

Question 29

what are plants?

Answer 29

dominants group of land organisms. VERY diverse, vary from 2mm to 300 ft. there are 290,000 known species, and some are aquatic.

Question 30

how are plants classified?

Answer 30

classified broadly by if they contain vascular tissue into categories of nonvascular and vascular. Vascular plants produce seeds, and nonvascular plants produce spores.

Question 31

vascular tissue

Answer 31

cells joined into tubes that distribute water and nutrients through plants. Roots require water and nutrients. `

Question 32

nonvascular plants (bryophytes)

Answer 32

have no roots. Water and nutrients are acquired through the leaves. Water moves in the plants and within the cells through osmosis and diffusion.

Question 33

spores v seeds

Answer 33

spores- haploid. have one cell and arises from a sporophyte through meiosis. fertilization occurs after dispersal. seed- diploid cells, are multicellular. contains an embryo which is a union of gametes from gametophyes (n). fertilization occurs before dispersal.

Question 34

bryophytes

Answer 34

-live in moist environments -small in size and are simple -gametophyte stage (n) dominant. the sporophyte depends on the gametophyte for nutrition. -lacks true stem, roots, and leaves as there is no vascular system to transport water and nutrients. they absorb water and nutrients from the environment through osmosis and diffusion. - require water for fertilization (sperm swim to the egg) -produce spores for asexual reproduction and dispersal

Question 35

nonvascular plants: liverworts

Answer 35

"leafy" and thalloid (simple and flat) form. lack stomata

Question 36

stomata

Answer 36

stoma- allow exchange of o2 and CO2. H2O evaporation occurs through these pores and can close during dry conditions to prevent water loss.

Question 37

nonvascular plants: mosses

Answer 37

about 12,000 species. 1mm-15cm. some are tall, more than 2m. Substrates include rocks, soils, acidic soils, logs and stumps, and bogs. Survive desiccation or freezing.

Question 38

nonvascular plants: hornworts

Answer 38

horn-like sporophyte

Question 39

vascular plants

Answer 39

-have alternation of generations. The sporophyte stage is dominant to the gametophyte stage. -have a vascular system, meaning xylem and phloem in the leaves and roots and leaves. -dominant sporophytes. 2n larger and more complex v the gametophyte n. -vascular tissue- conductive tissues that allows for transport of water, minerals, and photosynthetic products throughout the plant. two types are xylem and phloem

Question 40

xylem and phloem

Answer 40

xylem- flows upward, with water and minerals. has tracheids, which are tube shaped cells with cell walls strengthened with lignin. has vessels phloem- cells arranged in tubes. carries sugars, amino acids, and other organic products in all directions within the plant.

Question 41

vascular tissue

Answer 41

lignified tracheids have thick cell walls. allows for increasing morphological complexity, like branching.

Question 42

leaves

Answer 42

photosynthetic organ of vascular plants. increase the surface area in plants and are classified in two types; microphylls and megaphylls

Question 43

microphylls

Answer 43

small, spine-shaped leaves with one vein. Appeared 410 mya. Lycophtes.

Question 44

megaphylls

Answer 44

all other vascular plants. highly branched. When surface area is increased, then photosynthetic productivity is also increased. Arose 370 mya.

Question 45

roots

Answer 45

-anchor the plant -absorb water and nutrients from the ground -store food to be used later -evolved from lower most subterranean portion of stems

Question 46

seedless vascular plants

Answer 46

-have true vascular tissue, xylem and phloem -most have roots with lignified tissue -lack seeds -gametophytes reduced v bryophytes. develop from spores beneath the soil surface, and are often colorless and small. Some have no chlorophyll and derive nutrients with aid of fungi. -gametophytes-sperm use the flagella to swim to the egg. They live in moist environments as they need water for sperm to swim. reproduce and disperse through spores. -2 main groups- lycophytes and monilophytes

Question 47

lycophytes

Answer 47

-club mosses, spike mosses, quillworks -moist temperate forests -microphylls -dichotomously branching roots

Question 48

monilophytes (pterophytes)

Answer 48

-ferns, horsetails, whisk ferns -more closely related to seed plants than to lycophytes -megaphyll leaves (ferns and horsetails) -roots that branch (ferns and horsetails)

Question 49

traits of seed plants

Answer 49

sporophyte dominant, reduced gametophyes, heterospory, ovules, and pollen

Question 50

gametophytes of seed plants

Answer 50

microscopic, and still develop from spores. But, the spores are retained within the sporangia, and not released into the environment. It derives nutrients and shelter from the sporophyte. It protects it from desiccation and UV radiation

Question 51

heterospory

Answer 51

plants which have two kinds of spores. a megaspore, which is a female gametophyte. One megasporangium yields one megaspore. A microspore, which is a male gametophyte. One microsporangium yields many microspores.

Question 52

ovules

Answer 52

megasporangium. retained within the sporophyte. the megasporangium is protected by an integument. An integument is sporophyte tissue. one layer for gymnosperms, and one layer for angiosperms. Overall, an ovule contains the megasporangium, the megaspore, and the integument.

Question 53

pollen

Answer 53

pollen grain-develops from microspore and houses the male gametophyte (microgametophyte). pollen wall is made from sporopollenin, and pollen grain is dispersed by wind or animals. pollination- transfer of pollen to portion of seed containing ovules. uses pollen tube, which emerges after pollen tube germination. it discharges sperm into the female gametophyte. in pollination, water is not required for the sperm to swim long distances. That's why there is nonmotile sperm in gnetophytes, conifers, and angiosperms. Pollen can disperse long distances by wind or animals.

Question 54

Seeds

Answer 54

-contains an ovule an ovule has an egg and sperm (both n) which turns into a 2n zygote, then develops into a sporophyte, and eventually an embryo. the seed also contains a food supply. -advantages over spores- have longer lifetimes and a protective coat. Can be dispersed using wind or animals. An embryo itself is an advantage because it has more genetic variation. Having stored food inside the seed allows for the sporophyte to germinate and grow using stored food.

Question 55

pollination of seeds and pollen

Answer 55

seeds are more resistant, and can be dispersed in many more ways. Pollen are an airborne agent which brings gametes together.

Question 56

types of seed plants

Answer 56

gymnosperms- have a naked seed. Cycadophyta, ginkgophyta, ghetophyta, coniferophyta angiosperms- vessel seeds. Anthophyta, flowering plants.

Question 57

history of seed plants

Answer 57

360 million years ago, the first seed plants emerged. These species are extinct now. 305 mya, the first gymnosperms emerged 140 mya, the first angiosperms emerged

Question 58

gymnosperms

Answer 58

emerged towards the end of the Paleozoic era (305 mya). during the Mesozoic era (252 mya), gymnosperms began to become more prominent. Cycads emerged.

Question 59

Animals

Answer 59

-heterotrophs that ingest and digest food. -are multicellular. Have no cell walls, use collagen, and have nerve and muscle cells. -reproduction-diploid condition is dominant, and sexual reproduction is common. Meiosis produces haploid gametes. Has a zygote.

Question 60

history of animals

Answer 60

great diversity of animals, over 99% of species are extinct. Ediacaran fossils from 565-550mya were first animals. They were sponges and cnidarians. Others do not appear to fit any living land animals.

Question 61

porifera

Answer 61

sponges- basal animals which lack true tissues. They are monophyletic, most are marine, and sedentary. They are suspension (filter) feeders, and they are non-motile. -they are specialized cells but lack true tissues. choanocyte- has a flagella which moves water through pores, into a spongeoceol and out through an osculum. food particles become trapped, and phagocytosis occurs. amoebocyte- pseudopodia, moves around through the mesophyll. Transports nutrients to other cells. Produces structural fibers and can become other sponge cell types. regeneration- ability to replace lost/damaged body parts. Entire sponges can do this, as long as amoebocytes are present.

Question 62

ctenophora

Answer 62

"comb jellies" diploblastic- true tissues, with 2 primary germ layers from which tissues originate. these layers are called an endoderm and an ectoderm. They are symmetrical, and most are predators.

Question 63

cnidaria

Answer 63

corals, jellyfish, and hydras. Are also diploblastic. They are radially symmetrical and both sessile and motile. emerged 560 mya. morphology- have a gastrovascular cavity called a mouth anus. 2 types- polyps like sea anemone and hydras which do not move. Medusa like jellyfish which move freely. Some cnidarians can have both types through life changes. nutrition- they are carnivores. They capture prey with tentacles and push food into the GV cavity. undigested food is expelled through the cavity.

Question 64

cambrian explosion

Answer 64

-occurred in BC Canada. Fossils over half of our present-day animal phyla can be found here. This includes arthropods, chordates, and echinoderms. These animals are predators and have hard mineralized structures like spines and body armor -they are bilaterally symmetrical, and most have a complete digestive tract why decline in ediacaran diversity? -predator prey speciation allowed predators to develop traits to help them kill prey, like skeletons, plates, and other defensive structures. -increased oxygen meant higher metabolic rates and larger body sizes -Hox genes- allowed for different body forms. These are a group of developmental genes that controls body plan of bilaterally symmetrical animals

Question 65

animal body plans

Answer 65

have symmetry, tissues, and body cavities

Question 66

animal symmetry

Answer 66

2 types, radial and bilateral. Animals with radial symmetry are sessile, and interact with environment from all directions. Other type is bilateral. They are motile and have cephalization, which means they have sensory organs at anterior end; they move head first into their environment.

Question 67

animal tissues

Answer 67

tissues are collections of specialized cells which arise from germ layers. In animals, there are three germ layers. ectoderm- outer covering of skin (epidermis) and nervous system mesoderm- muscles, dermis, BV, bone, and other organs endoderm- lining of digestive and respiratory tract, pancreas, and liver.

Question 68

body cavities

Answer 68

3 types of body cavities. "true" cavity- space between digestive tract and outer body wall. Formed from the mesoderm. These are called coelomates. "false" body cavity- body cavity formed from mesoderm and endoderm. These are called pseudocoelomates. no cavity- acoelomates

Question 69

bilateria

Answer 69

majority of animal species are this, have bilateral symmetry, and are triploblastic (three germ layers) 3 clades- lophotrochazoa, ecdysozoa, deuterostomia. These dominated cambrian oceans, and majority were invertebrates.

Question 70

lophotrochazoa

Answer 70

most diverse clade of bilateral animals. There are 18 phyla.

Question 71

flatworms (platyhelminthes)

Answer 71

free living in aquatic and damp terrestrial habitats. they are predators and scavengers. there are parasitic forms likes trematodes (flukes) , and cestodes (tapeworms)

Question 72

molluscs

Answer 72

second most diverse animal phylum. Live in marine, freshwater, and terrestrial environments. Soft creatures with a hard protective shell made of calcium carbonate. reduced or lost in squids, slugs, and octopi.

Question 73

Annelids

Answer 73

segmented worms. Live in marine freshwater, terrestrial. They have a true cavity, so they are coelomates.

Question 74

ecdysozoa

Answer 74

has an external coat with a cuticle. It is tough and sheds as the animal grows. This molting is called ecdysis. this order contains more known organisms than all other animals, protist, fungus, and plant groups combined. There are 8 phyla.

Question 75

nematodes

Answer 75

roundworms morphology- cylindrical body. pseudocoelomate which contains fluid under pressure and keeps the body straight. Provides rigidity.

Question 76

Arthropods

Answer 76

10 to the 18th number of species. 1 million identified. 2/3 animals are arthropods. they are ubiquitous, meaning they can be found anywhere. They are the most successful of the animal phyla. origin- earliest fossils in the cambrian explosion. Have a segmented body, hard exoskeleton, and jointed appendages. over time, there is a reduction in segments, and the appendages became more specialized. More efficient because of division of labor among body segments.

Question 77

arthropod characteristics

Answer 77

cuticle- exoskeleton, composed of layers of protein and chitin functions- support and protection. Attachment point for muscles. Impermeable for water. molting ecdysis- must shed old exoskeleton to grow. expends energy to mold. Arthropod is susceptible to predation and desiccation during this time until the new exoskeleton hardens specialized appendages- walking, feeding, sensory reception, reproduction, defense, jointed and paired

Question 78

homeogenetic genes

Answer 78

hox genes- determine body plan and orientation, foundation and identity of body segments, express patterns like clusters from head to tail, overall help regulate development by turning developmental genes on and off. small changes in regulatory sequence leads to major changes in later form

Question 79

hexapods (insects)

Answer 79

ubiquitous evolutionary adaptation-flight, gymnosperms, flowering plant associations flight- have 1-2 pairs of wings on the thorax. These are cuticular extensions. Wings evolved once in insects because of heat collection, gliding, gills in aquatic habitats, and swimming apparatuses.

Question 80

insect life cycles

Answer 80

metamorphosis can be incomplete or complete. In incomplete metamorphosis, there is no major change in morphology, like grasshoppers and crickets. In complete metamorphosis, there are huge morphological changes, like flies and butterflies. Larvae is another example

Question 81

importance of insects

Answer 81

-can be herbivores, predators, parasites, and decomposers. -they are a food source for many animals and humans -pollinators -destroy crops and crop yields -cause animal and human disease

Question 82

life cycle of pine trees

Answer 82

pollen cones- smaller, have microspores which develop into male gametophytes, or pollen grains ovulate cones- larger, megaspores that develop into female gametophytes

Question 83

cycadophyta

Answer 83

cycads 2nd largest group of gymnosperms. Dioecious sporophytes with palm-like leaves. Have large cones and flagellated sperm

Question 84

gingkophyta

Answer 84

gingko bilboa is the only species deciduous, meaning lose leaves seasonally

Question 85

gnetophyta

Answer 85

3 genera

Question 86

angiosperms

Answer 86

phylum anthophyta vascular seed plants with flowers, which are sexual reproductive structures that are pollinated by wind and animals. have fruits, which contain seeds. most diverse and geographically widespread of all plant groups. they are 90% of all plants, and appeared 130 mya.

Question 87

flower structure

Answer 87

have 4 sporophyll rings have sterile floral organs- outer part of bud, sepals, and petals fertile floral organs- internal part of bud, stamens, and carpels

Question 88

petals

Answer 88

attract pollinators, like insects, birds, and mammals UV patterns in petals wind pollinated flower have no petals or dull petals

Question 89

fertile floral organs

Answer 89

stamen- made up of filament (support) and anther anther- contains microsporangium. microsporocytes (2n)- meiosis- microspore (n)- pollen grain (microgametophyte or male gametophyte) carpel-stigma (receive pollen), style, and ovary ovary- contains megasporangium megasporocyte (2n)- meiosis- megaspores (n)- female gametophyte

Question 90

fruit

Answer 90

mature ovary, but can include other flower parts ovary is fruit and ovules are the seeds. Mature fruit can be fleshy or dry.

Question 91

fruit function

Answer 91

protect seeds and aid in dispersal

Question 92

evolution of flowering plants

Answer 92

emerged 140 mya as the first angiosperms. Around the time of the Mid-cretaceous period (100 mya)

Question 93

flowering plant diversity

Answer 93

water lilies, star anise and relatives magnolids- magnolias, laurels, black peppers monocots- 70,000 spp. can be orchids, grasses, and others (lilies, daffodils, irises, amaryllis, and tulips)

Question 94

importance of angiosperms

Answer 94

food- 80% of all calories consumed come from 6 crops- rice, wheat, maize, potatoes, cassava, and sweet potatoes. food source is also spices, coffee and tea. can also be used for wood and lumber, medicines and botanical, flower industry, and landscape industry