Biology Notes For Midterm 3

Front 1

Mosses-Why do they need water?

Back 1

-non-vascular plants=have no conducting tissues to carry water, glucose, nutrients from one part of the plant to
another.
-Their rhizoids are not true roots.
-Their leaf surfaces are only one cell thick, so water and
minerals pass through very easily.
-They can only grow where there is abundant water for at least part of the year; reproduction depends absolutely on water.
-Sit on trees to get nutrients and rainfall from above

Front 2

Haploid/Diploid cycle

Back 2

-Eukaryotic cells typically contain 2 sets of
chromosomes: one set derived from the male parent
and one set from the female parent. Such cells are
called diploid (2N).
-Reproductive cells, eggs and sperm, and produced
by a process (meiosis) that reduces the 2 sets to
one set. These cells are haploid (1 N).
-When a sperm fertilizes an egg, two haploid cells
fuse to become a diploid cell, which once again has
2 sets of chromosomes.

Front 3

Alternation of Generations

Back 3

-In humans and most animals, the only haploid cells
are the eggs and sperm; all other cells are always
diploid.
-Mosses spend part of their lives as haploid (1N)
organisms and part of their lives as diploid organisms
(2N).
-Also happens with ferns-plant is sporophyte-has gametophyte stage

Front 4

Invertebrates

Back 4

-Multi-cellular w/out backbone
-Many live in the ocean
-Nematodes are the most numerous multicellular animals

Front 5

Nematodes

Back 5

-Most numerous multicellular animal
-smaller than earthworms
-fewer than 1000 cells
-1 millimeter long or less
-some eat fungi, bacteria, dead stuff, predators, roots of plants

Front 6

Arthropods

Back 6

-Most invertebrates
-phylum
-80% of all species
-body divided up into distinct segments
-legs that are jointed
-bodies covered in chitin-fingernail substance
-1 sq. meter of soil contains 200 species of arthropods and 200,000 individual arthropods
-A Berlese funnel is used to
determine what arthropods are
present in a sample of soil.

Front 7

Mites

Back 7

-8 legs instead of 6
-head and thorax is fused
-most numerous
-they are diverse:
decomposers
feeders on bacteria/fungi
predators or parasites of insects or other mites

Front 8

Springtails

Back 8

-6 legs
-possibly a relative of insects that evolved a little before other insects
-can jump many hundreds of times their own body length
-feed on fungal hyphae, spores, bacteria, feces, plant debris

Front 9

Pseudoscorpions

Back 9

-4-5 millimeters long
-Arms w/ pincers
-relatives of spiders

Front 10

Millipedes and Centipedes

Back 10

-Most are decomposers
-Some are predators

Front 11

Beetles

Back 11

-Undergoes complete metamorphasis from larvae to adult

Front 12

Flys

Back 12

-order of insects that undergo metamorphasis

Front 13

Epiphytes

Back 13

-Plants that grow on other plants
-In temperate PNW forests, lichens and mosses are diverse and abundant in tree canopies

Front 14

Tropical Rainforests: Epiphytes

Back 14

-Orchid epiphytes
-Bromeliads: Pineapples, spanish moss, etc.
-water that drips down trees give them some nutrients
-soil builds up in tops of trees made by falling debris and dead epiphytes-creates humus

Front 15

Tropical Rainforests: Canopy Humus

Back 15

-Some trees form roots in canopy humus
-canopy humus-less bacteria, less mycorrhizae
-insects that only live up high
-finding lots of new ants in canopy we've never seen before-gliding ants

Front 16

Ways that human activities can alter species interactions and bring about changes that "remodel" biological communities

Back 16

-The introduction of non-native species
-global climate change
-altering habitat and its uses
-removal of large "top" predators from communities

Front 17

Non-Native Species

Back 17

-introduced or alien species
-deliberate moving-farm animals, english ivy, exotic animals
-some escape control of humans and go wild
-accidental introductions-hitchhikers-seed, insects, snakes
-when humans move things it's fast-shock to community

Front 18

Native Species

Back 18

-some species are stopped by barriers i.e. water, mountains, climate conditions
-species that are native to an area got there naturally-have developed species interactions
-things move slowly-species have time to adapt and adjust

Front 19

Crazy Ants

Back 19

-Came to Christmas island 70 years ago
-20 years ago exploded to 1/5 Is.
-ants sprayed formic acid at native crabs which killed 3 million crabs in 1 1/2 years
-Crabs normally eat seedlings/leaf litter
-ants feed on scale insects' honeydew (excreted glucose)
-facilitated explosion of scale insects, which leads to excess glucose which leads to harmful tree mold on leaves

Front 20

Keystone Species

Back 20

any species that, because of its interactions with other species, has an effect on the structure of the community
far greater than would be expected on the basis of its size or biomass.
ex: red crab was native keystone, now crazy ant is non-native keystone

Front 21

Brassicaceae family

Back 21

-cauliflower, mustard, turnips, etc.
-doesn't do mycorrhizae relationships
-disrupts below ground mutualisms

Front 22

Earthworms

Back 22

-phylum of invertebrates
-they eat soil-move stuff around-process of decomp.
-areas of North America were covered by glaciers-worms aren't native there
-invaded sites have little plant matter
-consume leaf litter or drag it down, kill seedlings, bare patches of soil-subject to erosion
-contributing to global warming
-decline of salamander species, soil arthropods

Front 23

Global Climate Change: Bark Beetles

Back 23

-bore into living trees to eat and to make tunnels to lay eggs
-mutualistic fungus w/beetle, when female burrows, fungus enters the tree
-tree has sap to defend against beetles, the fungus clogs xylum vessels-blocks flow of water-tree stops making sap-goes into drought stress
-beetle sends out pharamones to attract other beetles
-because it's warmer longer, beetles moving to higher elevations since they might have a better chance of surviving w/out as much cold

Front 24

Altering habitat and its uses:Amboseli National Park

Back 24

-Woodlands changed to grasslands
-loss of biodiversity
• Elephants are migratory, so their damage is patchy and temporary.
• The grasslands they create are
favored by Maasai herders.
• Livestock grazing favors tree
seedlings over grass and promotes
tree regeneration.
• High rates of human population
growth, and the transition away
from a nomadic lifestyle, plus the
threat of poaching, concentrates
and prolongs elephant damage and
prevents woodland recovery.
• A 5-fold difference in elephant
density inside and outside the park
leads to grassland conditions in the
park and dense woodlands outside.

Front 25

Hypotheses to Explain the Disappearance of
Woodland in Amboseli NP

Back 25

• Maasai livestock overgrazed the area.
• The trees were killed by pests and pathogens.
• A rainfall increase raised the water table of the ancient
Pleistocene lake that underlies the park and increased the soil’s salinity, and that killed the trees.
• Locally overabundant wild herbivores may have overgrazed the woodland.
• Elephants have destroyed the woodland.

Front 26

Reasons that “top” predators are particularly susceptible to
endangerment/extinction

Back 26

• the species at the top of the food chain have smaller populations (remember the pyramid of biomass?)
• individual predators need a large range in order to find enough food; unless an area is very large, it may not support enough individuals for successful mating
• predators are often targeted by humans for extermination because they are seen as threats to livestock and (sometimes) to people

Front 27

Trophic Cascade

Back 27

-Snowballing effects
-Top Down
-Lake Guri-islands w/out predators had huge increase in herbivores/plants
-Yellowstone-grazers not in open, more trees near rivers-increase of life dependent on those streams

Front 28

Seed plant

Back 28

-Eukaryotic
-Multicellular
-Photosynthetic (or descended from photosynthetic ancestor)
-Decentralized control system
-Growth is indeterminate
-Life cycle alternates between diploid sporophyte generation w/ a haploid gametophyte generation
-Store glucose in form of starch

Front 29

Angiosperms

Back 29

Moncots and Dicots

Front 30

Monocots

Back 30

-grasses, bamboo, palms, orchids, lilies, bromeliads, corn, wheat, rice
-Leaf veins form parallel pattern
-Flower parts in threes/multiples of threes
-One cotlyedon in seed
-Vascular bundles scattered in stem
-Root xylem and phloem in ring

Front 31

Dicots

Back 31

-roses, maples, alders,tomatoes, ivy, legumes, garlic mustard, cherries, dandelions, potatoes
-Leaf veins form net pattern
-Flower parts in 4s/5s or multiples of 4s/5s
-Two cotlyedons in seed
-Root phloem between arms of xylem
-Vascular bundles in distinct ring

Front 32

Seed plants 2 organ systems

Back 32

-Root system
-Shoot system

Front 33

Root Systems

Back 33

-vary in shape/locations in soil
-all monocots and some dicots have a fibrous root system
-top of soil is where most organic material is where decomp. happens
-long, deep roots might avoid competition for water
-some dicots have a taproot
-plants in poor soil have more elaborate root system
-plants in low light have taller stalks to get to light.

Front 34

Fibrous root system

Back 34

-no one main branch
-all monocots and some dicots have this

Front 35

Taproot

Back 35

-one main root w/ small fibrous roots coming off it
-Some dicots have it
ex: carrot

Front 36

Stem systems

Back 36

-plumbing system throughout every part of the plant
-some use tendrils to crawl up other plants
-some are used for water storage-cacti
-leaves contain vascular tissue

Front 37

Leaves

Back 37

-Compound
-Simple
-Needles
-Broadleaves

Front 38

Advantages/Disadvantages of needles vs broadleaves

Back 38

• Needles don’t heat up as much in warm weather; they
conserve water otherwise used for evaporative cooling
• Broad leaves are better competitors for light (absorb light more effectively, and shade neighboring plants)

Front 39

Advantages/Disadvantages of evergreen vs deciduous

Back 39

• Evergreen leaves conserve nutrients because they do not
need to be re-created every year
• Deciduous leaves can be shed during droughts to reduce
water loss
• Deciduous leaves have higher rates of photosynthesis per
unit of leaf mass

Front 40

Organs in Plant Cell

Back 40

• Much of the volume is occupied by a water-filled vacuole
• This and cell walls provide rigidity
• Chloroplasts contain pigments (chlorophyll and carotenoids) and are the site of photosynthesis
• Anthocyanin (red pigment) is in the vacuole
• Respiration occurs in the mitochondria, chromosomes(DNA) is in the nucleus

Front 41

Fall in deciduous leaves

Back 41

• cessation of chlorophyll production reveals pre-existing carotenoid (yellow and orange) pigments
• development of abcission layer traps carbohydrates (i.e. stored sugar) in leaves, which under some conditions are converted to anthocyanin (red and purple) pigment

Front 42

Shoot System

Back 42

• Above ground
• Elevates and supports the leaves
• Photosynthesizes
• Reproduction and seed dispersal
• Conducts food and water

Front 43

Root System

Back 43

• Underground
• Anchors the plant in the ground
• Absorbs and conducts water and nutrients
• Stores food (glucose as
starch)