Ecology-Keystone Review 2015

Levels of Organizati

on

• Since energy is always lost as it is transferred, the amount of total energy (or biomass) decreases as we move up the pyramid.

• There will always be a much greater overall number of producers than there will be of the organisms that consume the plants.

• Top predators have a much lower population than animals below them on the chain.

Energy PyramidsAs you can see, the amount of

energy decreases by a factor of TEN for each level you move up the energy pyramid.In other words, when one organism

eats another, 90% of the energy is lost or used up and only 10%

passes into the consumer.

Scientists observed that the populations of top-level consumers in a particular ecosystem were rapidly decreasing. Further studies revealed that there was also a decline in producer productivity. Which other changes did the scientists most likely observe in the ecosystem? A. increased producer diversity B. decreased population size at all levels C. decreased primary consumer populations only D. increased primary and secondary consumer diversity

Ecological succession

• Building a new ecosystem from scratch• Takes time to build a

complete ecosystem with all roles (niches) filled Called a climax community

Secondary SuccessionWhen an earlier ecosystem is wiped out, a new one will gradually form in its place, and this process happens much quicker because soil and some tiny organisms are already present.

Interaction Organism #1

Organism #2

Examples:

Predation + (predator)

- (prey)

Cheetahs chasing gazelles; wolves eating moose

Commensalism

+ O (not

harmed)

Barnacles on whales (doesn’t hurt or help whale)

Mutalism + + Clownfish safe in anemone and anemone is cleaned by clownfish

Which example describes a mutualistic relationship between organisms?

A. Young wasps prey on caterpillars. B. Crabs eat the remains of dead fish. C. Ants protect a tree on which they feed. D. Tapeworms feed on food in the intestines of cats

Why are nonnative species often considered a disturbance in an ecosystem?

A. They increase mutations. B. They compete for resources. C. They have special growth needs. D. They cause increased biodiversity.

For the aye-aye species, what is most likely the primary value of individuals living alone?

A. decreased space needs for the species B. increased survival rates with habitat loss C. reduced competition for natural resources D. greater genetic variability within the species

Part A:

Describe one limiting factors for the moose population

Part A: Possible Limiting Factors (anything that stop population growth)-Predators - Lack of resources (space, food, water) due to living on an island

Part B:

Explain 1 reason why the wolf pop. Increased between 1975 & 1980.

Part B: Wolves increased because the moose population increased right before 1975 providing more food

Part C:

Predict what will happen to the moose pop. after 1994.

Part C: 1. Will drop & level off due to limited resources (reach carrying capacity) 2. Will decrease if the wolf pop. Increases (due to more food).

What is Evolution? Evolution = change in the gene pool (all genes in a population) over time

Evolution driven by Natural Selection Natural selection = individuals that are better suited to their environment will be more likely to survive and reproduce For Natural Selection to Occur: 1. Must produce more offspring than can survive (increase chance of some surviving) 2. Individuals must have different characteristics. 3. Offspring inherit characteristics from parents.

5 Fingers of EvolutionWrite this down first:

Pinkie

Ring

Middle

Index

Thumb

As we watch, write down what each finger stands for (all factors that change the gene pool)

Other factors that affect genetic variability

1. Genetic Drift- small number of individuals start a new population (only their genes are present) A. Bottleneck Effect- Catastrophe causes population crash and only few individuals survive B. Founder Effect- Small group leaves to start new population – reduces diversity)

Evidence for Evolution 1. Anatomy or physiology 2. Embryology 3. Biochemical Evidence 4. Fossils

Anatomy & Physiology 1. Homologous structures – same structure but different function 2. Vestigial structures – structures unused in present organisms; leftover from ancestors 3. Analogous structures- Resemble each other due to similar function but did not evolve from the same ancestor

Embryology

Similarities in embryonic development indicate similar ancestors.

Biochemical Evidence DNA is called the Universal Genetic Code All living things contain DNA or RNA. All DNA codes for the same mRNA codon. All mRNA codons code for the amino acid NO MATTER WHAT ORGANISM. Indicates relatedness Smaller number of amino acid/DNA differences = more closely related

Fossil Record Links organisms to past ancestors Shows change over time

The frequency of an allele in a fly population changes from 89% to 20% after three generations. Which other events most likely occurred during the same time period?

A. an environmental change and a fly population increase B. an environmental change and a fly population decrease C. interbreeding of flies with an invasive species and fly population speciation D. interbreeding of flies with an established local species and fly population speciation

Tail length in mice varies within a population. Scientists observed change in the distribution of tail lengths in a mouse population over time. At the genetic level, what has most likely happened to the allele for the shortest tail lengths?

A. The allele changed from being dominant to being recessive. B. The allele changed from being autosomal to being sex-linked. C. The allele became less frequent than the alleles for longer tail lengths. D. The allele began to code for long tail lengths instead of the shortest ones.

ATP → Form of energy used in cells (created during cell respiration) Used for active transport, protein synthesis, exercise etc. ATP - Adenosine TRIphosphate - 3 phosphates → High energy (release energy by breaking off last phosphate) ADP - Adenosine DIphosphate - 2 phosphates → Low energy

Sun = ultimate source of energy Autotrophs (producers)→ Plants Make own sugars during photosynthesis Provide food for all other organisms Heterotrophs (Consumers) Must get sugars (food) from other sources; cannot make their own

Photosynthesis Know Equation!!

Purpose: Create sugars (stores energy) Transform light energy to chemical energy

Location: Chloroplasts Light absorbed by chlorophyll found in mesophyll of leaves

Cell Respiration (Aerobic Respiration)

Know Equation!!

Purpose: Create energy (ATP) by breaking down sugars when oxygen is present Transform chemical energy in sugar bonds to ATP Location: Mitochondria

Anaerobic Respiration (Fermentation) Creating ATP when Oxygen is not present

Creates very little ATP compared to Aerobic

2 Types: 1. Alcoholic Fermentation Yeast use this Creates alcohol & CO2 as byproduct

2. Lactic Acid FermentationHuman muscle cells use thisLactic acid byproduct → muscle soreness

Which two statements correctly describe one similarity and one difference between cellular respiration and photosynthesis? 1. Cellular respiration and photosynthesis both involve water. 2. Cellular respiration uses sugar, and photosynthesis produces sugar. 3. Cellular respiration and photosynthesis both use light to produce energy. 4. Cellular respiration requires light energy, and photosynthesis requires chemical energy.

A. statements 1 and 2 C. statements 2 and 3B. statements 1 and 4 D. statements 3 and 4

Which statement best compares the energy transformations of photosynthesis andcellular respiration?A. Only photosynthesis uses oxygen to create energy.B. Only photosynthesis causes an increase in kinetic energy.C. Photosynthesis and cellular respiration both store energy in chemical bonds. D. Photosynthesis and cellular respiration both require chemical energy to make food.

The diagram shows an energy transformation that typically occurs in plant cell plastids.Which statement best describes this role of plastids in the plant cell?

A. Chloroplasts transform light energy into chemical energy.B. Mitochondria transform light energy into chemical energy.C. Chloroplasts transform chemical energy into electromagnetic energy.D. Mitochondria transform chemical energy into electromagnetic energy.