Download presentation
Presentation is loading. Please wait.
Published byGabriella Dorsey Modified over 6 years ago
1
Warm Up What type of feedback loop is occurring here? Why?
a) Increase in prey increase in predators decrease in prey
2
Homeostasis in a Changing Environment
Big Idea 2.D: Growth and dynamic homeostasis are influenced by changes in the environment
3
Essential Knowledge 2D1: All biological systems from cells to organisms to populations, communities, and ecosystems are affected by complex biotic and abiotic interactions involving exchange of matter and free energy. 2D2: Homeostatic mechanisms reflect both common ancestry and divergence due to adaptation in different environments. 2D3: Biological systems are affected by disruptions to their dynamic homeostasis.
4
Organisms Respond to External Environments
What is this called???
5
Made up of Biotic Things: Living
External Environment Made up of Biotic Things: Living
6
And Abiotic Things: Not Living
External Environment And Abiotic Things: Not Living
7
TPS: With your partner, make a list of 4 other biotic and 4 other abiotic factors that may affect organisms in an environment.
8
Case Study: Biofilms Bacterial cells attach to each other to form biofilms (a protective protein matrix cover) Communal group for protection and shared nutrients Grow w/ limited nutrients.
9
Cells Interact with Biotic/Abiotic Factors
10
Organisms Interact with Biotic/Abiotic Factors
Organisms access to nutrients is affected by other factors i.e. symbiosis, predator-prey, nutrient availability etc
11
Interactions Among Organisms
Symbiosis: relationship b/t 2 species Mutualism (+,+) Commensalism (+,0) Parasitism (+,-)
12
Mutualism Both Species Benefit Rhinos and oxpeckers
15
One member is helped, the other neither benefits or is harmed
Commensalism One member is helped, the other neither benefits or is harmed Cows and Cattle Egrets
16
Parasitism + and - relationship parasite benefits, host loses
parasite usually smaller than host Leech Bite, Thailand Lamprey
17
Ecosystems’ Stability is based upon interactions w/ biotic or abiotic factors
18
Evolution of Homeostatic Mechanisms
Some mechanisms are conserved- showing common ancestry Others have changed, demonstrating divergent evolution (due to changing envs)
19
Case Study: Nitrogenous Waste Removal
All animals produce N byproducts Animals in diff. envs. have evolved different mechanisms for excreting these wastes
20
Toxic byproduct of protein degradation
Ammonia, NH3 Toxic byproduct of protein degradation In dilute concentrations is no big deal, so aquatic orgs can excrete it into water
21
Urea Mammals convert NH3 into urea travels through blood to kidneys and is excreted w/ water and other substances as urine
22
Solid Uric Acid In birds and reptiles (and some desert mammals) N waste is excreted as a solid Prevents H2O loss and buildup of H2O waste in shell of an egg
23
Evolution of Circulatory System Shows Common Ancestry and Divergence
24
Evolution of Circulatory System Shows Common Ancestry and Divergence
25
Exs: viral infection of a cell, allergies, or dehydration in body
Disruptions at the Molecular/Cellular Level Affect Organisms Homeostasis Exs: viral infection of a cell, allergies, or dehydration in body
26
Disruptions to Ecosystems Affect Homeostasis
Exs: food chain disruptions, natural disasters, salination (adding salt)
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.