Midterm 1 Flashcards

Question

Cryosphere to Hydrosphere

Answer 1

Melting of ice sheets and other glaciers

Answer 2

-liquid water on Earth’s surface -sea levels are rising, the melting of the ice sheets and other glaciers -Ocean absorbs heat, taking up any extra energy -ocean warming up but slowly, causing tropical storms -Ocean absorbs CO2 and acidities: CO2 interacts with water (H2O) to create carbonic acid and free hydrogen ions. Free hydrogen ions bind to carbonate to make hard-to-use bicarbonate (rather than the carbonate that many organisms need) -As the ocean becomes more acidic effets marine life like corals, since they use CO2 to reinforce their shells

Answer 3

trajectories for greenhouse gas concentrations • 4 possible climate futures • Time at which the global greenhouse gas emission peaks and starts dropping • RCP 2.6: global annual GHG emissions peak 2010- 2020, then decline significantly • RCP 4.5: global annual GHG emissions peak 2040 • RCP 6.0: global annual GHG emissions peak 2080 • RCP 8.5: global annual GHG emissions continue at current level The number (2.6, 4.5, ….) refers to the strength of greenhouse effect (called “radiative forcing”) predicted in year 2100 Bigger number means more greenhouse effect (because of more greenhouse gases)

Answer 4

Genetic diversity: different in genotypes of individuals of the same species Species diversity: different species occupying same habitat at same time Other levels: different species assemblages in different habitats/ecosystems, species sharing evolutionary history, diversity in organisms’ ecological roles

Answer 5

-Not ever where -most in the tropical

Answer 6

• Market value: make money of plants •Ecosystem services: bee pollinating • tourism/recreation: open money to go into parks • cultural and intrinsic value: a part of us •science research: discover, know things • enjoyment: positive impacts on people mental health

Answer 7

Diversity Index- D Species richness= total # species in habitat Species evenness= relative abundance of each species 𝐷 = (𝑝1^−𝑝1)(𝑝2^−𝑝2) (𝑝3^−𝑝3)…(𝑝𝑛^−𝑝𝑛) p is the proportion of individuals of that species

Answer 8

Nothing would change, it's all about propotion

Answer 9

In most cases, you cannot directly count every organism Instead, you may use quadrats or point counts, and then extrapolate from this sample to the whole group

Answer 10

Instead of diversity as a function of area, we can look at diversity as a function of the # individuals sampled plots of the number of individuals on the x-axis against the number of species on the y-axis.

Answer 11

A higher D value = steeper curve

Answer 12

The geographic separation of a species into separate populations through some sort of physical barrier • continents were one Pangea) • plate tectonics: broke Pangea into continents • land bridge • people building roads

Answer 13

•70% water by weight •Ions and small molecules • macromolecules

Answer 14

• Proteins: are chains of amino acids - 20 amino acids -building blocks of: Carbon, Nitrogen, Hydrogen, Oxygen • nucleic acids: DNA and RNA -Nucleic acids include RNA (ribonucleic acid) as well as DNA (deoxyribonucleic acid). Both types of nucleic acids contain the elements carbon, hydrogen, oxygen, nitrogen, and phosphorus. • carbohydrates (polysacchorides): Glucose is C6 H12 O6 - starch and glycogen • Lipids

Answer 15

The atmosphere contains gaseous forms of carbon and nitrogen, but these are not easy to convert to more useable forms.

Answer 16

Carbon and nitrogen have to be “fixed” to become useful to most organisms. This kind of fixation was limited to prokaryotes (bacteria and archaeons).

Answer 17

Carbon fixation is storing the atmospheric carbon as a carbohydrate, typically as glucose Only bacteria could do this originally, but green plants gained this ability through a symbiosis with a cyanobacterium. A cyanobacterial symbiont became the chloroplast organelle

Answer 18

Nitrogen-fixation also occurs in bacteria and some archaeons. Gaseous nitrogen is comprised of two molecules of nitrogen with a triple bond between them. This triple bond is very hard to break and requires the enzyme nitrogenase The product of nitrogen fixation is ammonia. In this form, nitrogen is available to many other organisms

Answer 19

Photosynthesis occurs when atmospheric carbon (CO2) is ”fixed.” Fixation is storing the carbon as a carbohydrate, typically glucose

Answer 20

•A carbon source •An electron donor •Light energy (photons) and a pigment to harvest the energy •Bacteria use bacteriochlorophyll, plants have other pigments.

Answer 21

6CO2 + 12H2O + photons → C6 H12O 6 + 6O2 + 6H2O carbon dioxide + water + light energy → carbohydrate + oxygen + water Oxygen is released into the atmosphere. This is oxygenic photosynthesis where carbon is fixed. Photosynthesis that's not oxygenic, but also Photosynthesis when oxygen is released

Answer 22

•Autotrophs live exclusively on inorganic sources of carbon, nitrogen, and other essential resources. • There are chemoautotrophs and photoautotrophs. photoautotrophs which use sunlight as an energy source for metabolism and growth. 6CO2 + 12H2O + photons → C6 H12O 6 + 6O2 + 6H2O carbon dioxide + water + light energy → carbohydrate + oxygen + water

Answer 23

Plants have 2 major body divisions: the root and the shoot. Light is harvested in the shoot using pigments.

Answer 24

The shoot system consists of stems and leaves, in which photosynthesis takes place

Answer 25

The root system anchors the plant and provides water and nutrients for the shoot system

Answer 26

Pigments absorb different wavelengths • shorter wavelengths are more energetic • longer wavelength are less energetic • high wavelength = lots of light absorbed • each wavelength have peak absorption, have two peaks •

Answer 27

The color of a plant is what it's reflecting

Answer 28

• Chlorophyll a: All plants (absorbs at 350-430, 600-700nm) • Chlorophyll b: land plants + green algae, (420-470, 580-630nm) • Chlorophyll c: dinoflagellates, diatoms, brown algae (400-440, 590-610 -minor) • Xanthophyll (fucoxanthin): diatoms, brown algae (400-500nm) • Phycocyanin: cyanobacteria (500-650nm) • Phycoerythrin: red algae (450-550nm) What every it's mim is, is what its reflects

Answer 29

the relationship between the benefits of a trait in one context and its costs in another context Ex: Why might Anacharis have 3 pigments? - making 3 pigments allows the absorption of more pigments. However reflecting these 3 payments spend more energy making these Ex: Why might two organisms living in the same place have different pigments? - so you are not in competition with each other one could live in light and other in shadow.

Answer 30

all life functions cannot be simultaneously maximized

Answer 31

Autotrophs live exclusively on inorganic sources of carbon, nitrogen, and other essential resources. • shoots collects photosynthesis • CO2 entire and O2 and H2O exit the leaves through pores on the leaf surface called stomata

Answer 32

the downside of opening stomata, plants could dry out - under leaf to not dry out in the sun - H2O enter through the roots

Answer 33

In 85% of the plants, the carbon from CO2 is accepted by a 5-carbon structure called RuBP. CO2 is fixed when the enzyme rubisco adds one carbon to RuBP to make a 6-carbon compound. - mesophyll cells have rubisco and fix CO2 to RuBR to form 3PG • C3 plant •C4 plant •CAM plant

Answer 34

This 6-carbon compound quickly breaks into two 3-carbon compounds (3PG, so they are called C3 plants) that result in glucose production via the Calvin cycle. All this takes place in the mid-leaf cells called mesophylls.

Answer 35

Stomata: the more open they are, the more CO2 can enter, but the more water is lost (a trade-off). Most stomata open and close via guard cells, but this takes energy. The enzyme rubisco binds CO2, but it also binds oxygen, so stomata stay open a long time to collect C02 Binding oxygen results in production of a 2-carbon compound that has to be modified to enter the Calvin Cycle—the cost of modification reduces net carbon fixed by 25%. This is photorespiration. Fixed only get 75%

Answer 36

In about 8000 plants, mesophyll cells have a new enzyme, PEP, that binds CO2; PEP has a low affinity for oxygen, so stomata don’t need to stay open as long and it works if stomata are partially closed. PEP carboxylase catalyzes formation of a 4-carbon storage compound. The 4-C compound diffuses into the bundle sheath cells. There CO2 is released!! The extra CO2 prevents oxygen binding. Rubisco catalyzes the fixation of CO2 to 5-C RuBP so there is a 6-C compound that quickly makes two 3-C compounds for glucose production. This all takes place in the sheath cells. More ATP is spent in the process. Better at high temperature, low CO2, and in drought conditions. Initial CO2 fixation is spatially separated from the carbon fixation that leads to glucose production

Answer 37

It is cooler at night, so stomata open then. Photosynthesis requires light, so why do this—what is the trade-off? -CO2 is fixed at night in mesophyll cells as a 4-carbon storage compound. It stored overnight in the cell vacuole. -In the day, the 4-C compound moves to chloroplasts in the mesophyll cells. There CO2 is released!! Rubisco catalyzes the fixation of CO2 to 5-C RuBP. The resulting 6-C compound quickly makes two 3-C compounds for glucose production. The stomata are closed all day. Initial CO2 fixation is temporally separated from the carbon fixation that leads to glucose production.

Answer 38

carbon, hydrogen, oxygen, nitrogen, and phosphorus.

Answer 39

Carbon and nitrogen are present in gaseous forms, but they require special enzymes to ”fix” them into biologically useful forms. Bacteria and forms derived from bacteria, such as a chloroplasts in plants, do this.

Answer 40

In addition to carbon, plants need macronutrients (e.g., nitrogen (N), phosphorus (P), potassium (K) and micronutrients (e.g., iron (Fe), Calcium (Ca), etc). If a plant is short of a micronutrient, then the shoot grows poorly. Where do plants get micronutrients and water? Roots Nitrates and nitrites and phosphates are usually negative ions that are water soluble; plants absorb them with water. K and Ca are positively charged ions where uptake is active.

Answer 41

1) Plants form symbiotic relationships with root-loving fungi called ecto-mycorrhizae. The fungi increase the root foraging area and may even connect plants with their neighbors 2) The roots of leguminous plants form symbiotic relationships with a bacteria called Rhizobium that fixes nitrogen as ammonia. Nitrogenase does not work in the presence of oxygen, so plants invest energy in binding the oxygen to protect the bacteria.

Answer 42

Plant make CO2 to give sugar to the fungus

Answer 43

Leguminous plants: protect bacteria

Answer 44

• Autotrophs live exclusively on inorganic sources of carbon, nitrogen, and other essential resources. There are chemoautotrophs and photoautotrophs. • Heterotrophs use pre-formed organic molecules (those made by other organisms) to acquire carbon, nitrogen, energy, and other essential resources. They eat other organisms of all types. • “Functional groups” of organisms share a mode of living such as heterotrophy, or carnivory

Answer 45

Heterotrophs can be herbivores, carnivores, omnivores or detritivores Herbivores spend a lot of time feeding and may need a diverse diet to meet all nutritional needs. Carnivores feed much less frequently

Answer 46

Heterotrophs may be generalists eating many different foods, like this locust, Pro: more food choices or specialists like this tobacco hornworm that feeds only on tobacco and its relatives. Pro: not a lot of competition Cost: detoxifying the poison

Answer 47

Stress on organisms can be abiotic e.g., heating, cooling, drying, excessive wetness, salt concentrations, acidity, etc. We will look at temperature stress. Stress on organisms can biotic: e.g., consumers, competitors, etc. We will look at stress as a result of consumers (predators/herbivores)

Answer 48

Changes in temperature affect: (1) the rates of biological reactions. (2) the shapes of proteins, including the shapes of enzymes, so some processes may not work at extreme temperatures. (3) the properties of biological membranes required for cell integrity

Answer 49

Organisms cope at the cellular level: 1. Organisms can make heat shock proteins (hsp’s), also called chaperonins, to stabilize the structures of other proteins and prevent inappropriate binding. Cost a lot to do this Hsp’s are present in almost all life from bacteria to humans. 2. Organisms can produce several versions of enzymes, each suited to different temperatures.

Answer 50

(1) some archaeons live in volcanic sulfur springs at 163 degrees Fahrenheit. (2) Organisms have zones where they can regulate temperature, with and without spending energy. •Within the thermoneutral zone, body temp is regulated by low energetic cost mechanisms, such as changes in blood flow to the skin and changes in posture •Below the lower critical temp, the animal expends energy to produce metabolism heat •Above the upper critical temp, the animal expends energy to lose heat by panting or sweating

Answer 51

Ectotherms: body temperature determined primarily by external conditions. •Outside temp • behavior allows it to regulate temp ie. Hind underground for more heat. Uses less energy • exposing darkly pigmented back to the sun increases heat gain by radiation • pressing flat against tree reduces heat loss by conduction •ectotherms rely on morphological and behavioral mechanisms of temp regulation

Answer 52

Endotherms: body temperature determined primarily by internal, metabolic rates. • cost more in cold weather • easy to stay at thermoneutral zone •Endothermy is a high-benefit/high-cost strategy that works when resources (fuel for producing heat) are predictably abundant. •Conduction is the direct transfer of heat when objects of different temp come into contact •Warmer objects lose heat to cooler objects by radiation •Evaporation of water from body surfaces or breathing passages cools he body

Answer 53

Leaf morphology: •Reflective leaves reduce radiation gain. Dark leaves increase radiation gain Plant morphology: •Arctic and high altitude -Low growth form reduces loss to conduction -Hugs ground to gain conduction from rock -Leaves perpendicular to the sun’s rays to increase radiation gain •Desert -Open growth form results in high loss to conduction -Open form has less conductive gain - Leaves parallel to the sun’s rays to reduce radiation gain

Answer 54

Endothermic: •In rabbits, blood flow to ears with a large surface area allows heat exchange with the environment. •Body shape conserves or releases heat—compare bunnies. Ectotherms: •Even ectotherms regulate blood flow to the skin; here iguanas increase heart rate to bring more blood to the skin to warm up. •Behavioral regulation also occurs—e.g., spray water on yourself

Answer 55

High heat of vaporization: • sweating uses evaporation of water to cool the body Cohesion: •waters cohesive strength helps it flow from the roots to the leaves in a tree • as water is lose through stomata, root constantly bring water up through the plant

Answer 56

• Plants can vary the number of stomata present by shedding leaves or making new leaves with fewer stomata. • Some plants that live in extremely dry habitats (xeric habitats) have stomata in internal pockets (crypts); hairs called trichomes reduce air flow to the pocket.

Answer 57

Ice crystals inside cells destroy cell organelles and membranes. In response: • Intracellular water is moved to the extracellular space. • Urea and glucose are added to cells to act as a natural antifreeze. These frogs freeze solid and still survive; most organisms cannot do that. There are some thermogenic plants like the eastern skunk cabbage

Answer 58

Probability (p) of being eaten = p (detection). Reducing any of these factors increases survivorship (benefit), but adaptations are costly. Costs: (1) Need to stay in that habitat (2) Reduced feeding time Avoiding detection: camouflage or hiding

Answer 59

Probability (p) of being eaten = p(capture) Reducing any of these factors increases survivorship, but adaptations are costly. Avoiding capture: schooling, herding, masting. Costs are increased numbers of competitors

Answer 60

Avoiding consumption: (1) physical defenses -Costs are in making the defense. (2) Plants and slow-moving animals may be easily caught, so they often have chemical defenses. -

Answer 61

Induced animal defense example in the small aquatic arthropod ' Daphnia. The invertebrate predators Chaoborus and Notonecta induced longer helmets, while the fish Lepomis induced shorter bodies but had no effect on helmet length. Longer tail spines (relative to body length) were induced by Notonecta and Lepomis. The responses of D. retrocurva were influenced by algae concentration, with the more extreme responses occurring at a higher food concentration and higher lipid index.

Answer 62

•Adaptation: evolutionary change in genotype that maximizes performance Inuit people have lived above arctic circle for 10,000+ years Barrel-shaped body, short limbs, subcutaneous fat all over body incl. hands, shunt blood to extremities •Acclimation: change in phenotype within an individual's lifetime to maximize performance (usually reversible) World's greatest long-distance, col water swimmer Body optimized at 40% body fat (internal wet suit)

Answer 63

The lifetime pattern of growth, reproduction, and survival for an average individual.

Answer 64

The way in which individuals within and among species allocate resources to growth, reproduction, and survival based on genetic and environmental factors

Answer 65

• Few offspring, poor dispersal, lots of resources per offspring • many offspring, broad dispersal, little investment per offspring

Answer 66

Principle of allocation: Tradeoffs exist and there is no way that all life functions can be maximized simultaneously; there must be compromises between competing demands. Each of these life history questions deals with resource allocation. Any answer to one question has consequences for allocation to other events in the life history

Answer 67

•Reproduction diverts energy from growth. •Size at first reproduction varies. Reproducing earlier generally means reproducing at a smaller body size. The sooner offspring are made, the sooner they can make offspring, so there can be a advantage to reproducing early (compound interest argument). •If delaying reproduction means you will make more offspring once you start reproducing, then delays can be advantageous, but there needs to be a high likelihood of living that long. - however, you may die before this

Answer 68

•In some cases, male animals begin to reproduce early and remain much smaller than females. - the available of sperm is early so they reproduce early meaning less energy to grow •Reproductive males are smaller than reproductive females in spiders and Crepidula. -competition to find a female to mate with •Reproductive males are many times larger than females in Northern elephant seals. - high competition with other males. Protect females, have to fight

Answer 69

•Semelparous means you only reproduce once; •iteroparous means you reproduce several times.

Answer 70

Offspring: many small - dispersed; limited parental care Parental size: small body size Life span: short life Allocation pattern: Allocate to rapid growth Reproductive timing: Early reproduction Number of reproductive events: Semelparous (high effort) Population Density: Environmental conditions keep the population at low density Habitat: Unpredictable, variable, harsh or disturbed Sources of mortality: Mortality is independent of other organisms and often catastrophi

Answer 71

Offspring: Fewer large -Not dispersed; more parental care Parental size: Large body size Life span: Longer life - Allocation pattern: Allocate to slower growth, persistence, and defense Reproductive timing: Delayed reproduction Number of reproductive events: Iteroparous Population Density: Environmental conditions allow populations of reach high density Habitat: Predictable and favorable for growth and survival Sources of mortality: Mortality is often caused by interactions with other organisms

Answer 72

Equations are just (technically precise) sentences. The change in population depends on births, deaths, and migration into and out of the environment ∆𝑁 = 𝐵 − 𝐷 + 𝐼 − 𝐸 • N = current population size ∆N = the change in population size • B = number of births • D = number of deaths • I = number of immigrants • E = number of emigrants

Answer 73

Let’s ignore migration, then… ∆𝑁 = 𝐵 − 𝐷 • Births come from a birth rate (b) times the population size N • Deaths come from a death rate (d) times N ∆𝑁 = 𝑏𝑁 − 𝑑𝑁 = 𝑏 − 𝑑 𝑁 = 𝑟𝑁 • We call r the intrinsic growth rate of a population. It incorporates birth and death Sentence version: the change in population size equals the intrinsic growth rate times the current population size

Answer 74

We can “solve” the previous equation to get a prediction for the ' ' population size at time t. 𝑁𝑡 = 𝑁0𝑒𝑟𝑡 Sentence version: The population at time t depends on the initial population size and grows/declines exponentially through time (r determines the exact rate) Nt is population at time t (in whatever units), N0 is population at time 0 For a population with 500 individuals, with r = 0.25 (per year), what will the population be after 10 years? 500*e^(0.25*10) = 6091.2 ≈ 6091 individuals

Answer 75

In reality, N is usually unknown, so it’s simpler to rewrite as 𝑁 =(𝑛1 ∗ 𝑛2)/𝑀 (n1/N) = (M/n2) n1: marked initially N: estimated population size M: marked recaptures n2: total in second sample

Answer 76

•Generally, we expect exponential growth when looking at small populations that are recovering or newly established at a location • Some r-strategist species (like the variety of grasshoppers referred to as locusts) will have exponential growth combined with periods of rapid mortality • decline: lost of habitat • If a population is able to reach a large enough size, population growth will slow down and eventually stop

Answer 77

•Factors affecting population size that DO NOT depend on the number of organisms in the population, usually abiotic factors - drought: weather •Factors affecting population size that DO depend on the number of organisms in the population, usually biotic factors -Density-dependent controls prevent a population from growing forever - disease - predation - limited resources (e.g. Space)

Answer 78

(dN/dt) = rN [(K-N)/K] Just one new term affectinggrowth rate (K-N)/K Sentence version: the change in population size equals the intrinsic growth rate times the current population size times a factor that shrinks as the population size approaches K. When N is large, (K-N)≈0, so (K-N)/K ≈0 Growth slows to 0 When N is small, (K-N)≈K, so (K-N)/K ≈1 Growth is nearly exponential

Answer 79

Nt= {K/1+[(K-N0)/N0]e^(-rt)]} This term goes to 0 as t increases (so Nt goes to K). This happens faster when r is larger.

Answer 80

r-strategist species tend to have a high intrinsic growth rate (r), but density-independentfactors prevent populations from reaching their carrying capacity

Answer 81

K-strategist species tend to have lower r and population size is often near carrying capacity K