BIO220H1 Lecture Notes - Lecture 16: Polyculture, Genetic Variation, Species Richness

38 views3 pages

azuresquirrel208

19 Apr 2012

School

Department

Course

Professor

For unlimited access to Class Notes, a Class+ subscription is required.

qq919649100 and 40133 others unlocked

BIO220H1 Full Course Notes

Verified Note

38 documents

Document Summary

Lecture 16 bio220 ecological consequences of genetic variation. Biodiversity resistance to perturbation, increased productivity e. g. high species richness, high biomass after drought. Are plant patches that are more genetically diverse able to support more insects: grow groups of monocultures (only 1 genotype), or polycultures (mixture, measure # and identify herbivores, omnivores, predators. Result: more genetically diverse plant communities support more predatory insects. Polycultures recover from severe disturbances faster, are more resilient to natural disturbance. Mechanism: polycultures: more tolerant genotypes, can regrow quickly, overperformance of polycultures: interaction between genotypes, different resource uptake strategies of genotypes, more micro-niches, less competition. Galled plants decompose slower, have greater retention of c/n compared to ungalled. Genetic variation affects nutrition cycling: chain of causation, genotypes differ in chemical properties, different attack by insects, genotypes differ in chemical responses to attack, combined set of chemical differences alter decomposition, nutrition cycling. Coyote bush: facilitates colonization of other species.

Related Questions

1. Late stage succession communities typically: a) contain more equilibrial than opportunistic species b) are more diverse than disturbed communities c) are more diverse than early stage succession commmunities d) contain more opportunistic species than equilibrial species e) suffer higher rates of disturbance

2. Phenotypic plasticity is when: a) Organisms adapt their genotype to the local environment b) Individuals with different phenotypes show plasticity in their size c) Organisms with different genotype express different phenotypes in the same environment d) Plasticity in the environment causes different genotypes to survive leading to different phenotypes e) Organisms express different phenotypes depending on the local environment but have the same genotype

3. Terrestrial areas that are saturated with water, either permanently or seasonally, are typically known as what type of ecosystem. f) Grasslands g) Heathlands h) Litholands i) Wetlands j) Littoral

4. Briefly explain two ways that excess climate gas emissions are changing the worldâs physical environment

44.Why donât similar genotypes always produce the same phenotype?

A. Parent alter their phenotype and pass on this phenotype to progeny

B. Phenotype is the product of many environmental influences

C. Genetic variations of ADH enzyme produce the same phenotype

D. Animals display different phenotypes dependent on diet, not genotype

46.Which of the following attributes has the least effect on the contribution an individual makes to the gene pool of the next generation?

A. spas of mating privileges

B. more efficient at obtaining food

C. produces more offspring

D. camouflage from predators

47.âUntil the agricultural evolution 10,000 years ago, people used to live in small populations with little gene flow between them. That is the best situation for rapid evolution.â said Sewall Wright. one of the founders of population genetics. This conclusion on gene flow conflicts with Hardy Weinberg equilibrium, which states that no gene flow means

A. natural selection

B. no evolution

C. no random mating

D. no genetic drift

58 Larval flies (maggots) express the Ubx gene in all of their segments, and thereby lack appendages. If this same gene continued to be expressed throughout subsequent developmental stages, except in the head region, and if the result was a fit, sexually mature organism that still strongly resembled a maggot, this would be an example of

A. homochrony

B. exaptation

C. paedomorphosis.

D. adaptive radiation

raspberrymole848

How predation causes phenotypic and genetic diversification on the predators and preys?

BIO220H1 Lecture Notes - Lecture 16: Polyculture, Genetic Variation, Species Richness

BIO220H1 Full Course Notes

Document Summary

Get access

Related textbook solutions

Molecular Cell Biology

Biology: Science for Life with Physiology

Concepts of Biology

Biology

Essentials of Biology

Related Documents

BIO220H1 Lecture 18: Lecture 18.docx

EESC3310 Lecture Notes - Lecture 10: Legume, Evapotranspiration, Spatial Design

RENR 205 Study Guide - Midterm Guide: Abo Blood Group System, Reaction Norm, Allele

Related Questions