3. Coping with Environmental Variation

Phenotypes definition

product of genes interacting with environmental conditions

Genotype definition

Individual’s complete genetic makeupe

Phenotypes and the environment

traits have genetic basis but the environment turns on/off certain genes so different phenotypes develop 

Phenotype fitness 

phenotypes experiences higher fitness in one environment compared to challenging environments 

Phenotype plasticity

The ability of a single genotype to product phenotypes

Types of phenotypic plasticity

• morphology

• physiology

• behavior

• life history

• Phonology 

Morphology def.

physical defenses, height, size of digestive tract to extract more nutrients

Physiology def.

digestive enzymes, chemical defenses

Behavior def. 

habitat use, aggressiveness

Life history def. 

sexual maturity, clutch size

Phonology def. 

time to start reproduction

Metabolism def.

The sum of an organism’s biochemical reactions that acquire, use energy and tend to maintain homeostasis (steady internal conditions)

Catabolism def.

breaking down existing molecules

Anabolism def.

Building large molecules from smaller ones

Importance of temperature

Intensity of heat: average kinetic energy of the molecules in object/ system

Organism regulate internal temp in different ways 

Thermal Neutral Zone Def. 

The temperature range over which an endothermic animal at rest can maintain its metabolic rate and temperature without appreciable change 

Critical upper / lower temperatures def.

Temperatures disrupting metabolic functions and cellular components in the organisms, important changes can be detected (shivering, cooling)

Types of transfer of heat:

• Radiation

• Connection

• Conduction

• Evaporation (cooling)

Radiation def.

Heat transfer between two objects in absence of direct contact (NO CONTACT) 

Convection def.

The transfer of heat energy by mass movement of a fluid (gas/liquid)

• air, water, weather, etc. 

Conduction def.

The transfer of energy (heat) from one place to another directly (by physical contact), Heat flows down a gradient from warmer to cooler areas 

Evaporation def

Loss of water in the form of vapor. Heat is transferred from an organism to its surroundings as water evaporates from the organisms’s surface.

Energy exchange in terrestrial plants

heat convention & conduction

solar radiation 

heat envirotranspiration

infrared out/in 

Heat conduction 

Change in heat equation for plant 

ΔH plant = Solar + IR in - IR out +- H conv +- H cond - H evap

Physical Modifications In energy exchange

Hairs/ trichomes to increase pubesence and reflectance (thermoregulation)

Thermoregulation

Regulation of temperature

• Ecotohermes

• Endotherms 

Thermoregulation equation

ΔH animal = Solar + IR in - IR out +- H conv +- H cond - H evap + H met

Ectotherms def.

Regulate body temp through energy exchange with external sources (environment) 

Endotherms def.

Rely primarily on internal heat generation, remain active below freezing temperatures, demand more energy (food) to support metabolism. 

Physical modification and behaviors

• lizard laying on hot wood for heat

• elephant spraying itself with water with trunk to cool down

• Bunny lifting ears to cool

Blood vessles vains and artiers can be

consturcted when cold causing less heat

Core body temp is higher then external limbs bc

the counter  current exchange system, heart to limbs coold limbs to hear heat, lets body be warmer then air temperature to survive in cold 

Water internal balance def.

water content in most organisms represents a high percentage of their body mass

Transport tissues in vascular plants

Xylem: transports water and soluble mineral nutrients up

Phloem: translocates sugars made by photosynthetic areas

Variation in solutes

Isotonic

Hypotonic

Hypertonic

Isotonic def. 

Flaccid (neutral water in/out)

Hypotonic def.

Turgid (bursting) (too much water in)

Hypertonic

Plasmolyze (shrinked up, hyper in small water amount) (too much water out)

Trade offs with photosynthesis

• Carbon dioxide + water → glucose + oxygen

• 6CO2 + 6H2O (Light(energy) →) C6H12O6 + 6O2

Stooma opened vs stoma closed

Stoma open during day

• stoamtes open

• Water travels up

• more water flow in leaf, stem, roots

• carbon doxide intake allowed

Stoma closed during night

• stoamtes closed 

• more water still, to prevent water loss

Physical modifications for balancing water

Desiccation-tolerant organisms

tardigerades can curl up into a ball - anhydxroobotic tun state when in extreme dehydration

Moss having water and not

Barriers to desiccation (dryness, dehydration)

• Cuticle

• Skin

• Hair

• Trichomes (hair like outgrowths on plants)

• wax

Water balance in kangaroo rat

even between gains and losses

Salinity def.

The state of having high water aka high saline

Adaptations to salinity

Rapid changes of salinity:

Copeped trigous sp - synthesis amino acids to increase the osmotic (osmosis: flow of water) potential to the body fluids and match the environment 

When have extreme condtions an organism often….

Migrates to survive

Migration def and ex.

The seasonal movement of animals from one region to another

• Temperature

• darkness

• flood supplies

• water supplies

• Reproduction

• predation

Storage of rescues def. 

reserve of enegy in the tissues: roots of organisms 

Dormancy def.

Dramatic reduction of the metabolic processes (physiological shutdown)

Diapause: insects

Hibernation: mammals

Torpor: small birds and mammals

Aestivation: snails, desert tortoises, nile crocodiles