AP Biology Discussion Notes

Wednesday 11/04

Goals for the Day

1. Be able to understand OSMOregulation based on what you know about osmosis & diffusion.

2. Be prepared for our Lab quiz tomorrow

11/04 Question of the Day• What 2 things are the main regulators of

whether something can move across the cell membrane?

Part 1

• Water –

• Iodine –

• Starch –

• Glucose -

Part 1 • Water & starch outside

• Iodine & Glucose -inside

??

Quiz Thursday• Lab Questions & CALCULATIONS• Know how to calculate (and graph)

– % change

• Water Potential Questions & CALCULATIONS!!

Work order for today• Video Notes on Osmoregulation

– Added later to 2nd Notebook (just like cell parts)

• 2nd Notebook for Diffusion/Osmosis Lab• Read pages 184-192 (just finish paragraph

at the top of the page) in the text book and take notes.

• A couple invitations…– Today after school bring your questions and

work on lab or other materials (quiz Thursday!)

11/04 Species of the Day

Atlantic Bluefin Tuna -Thunnus thynnus

11/04 Species of the Day

Atlantic Bluefin Tuna -Thunnus thynnus

• Relative to it’s body cells, what type of solution does the Bluefin Tuna, an ocean dwelling fish, live in?

• What does the Tuna do to protect itself from this situation?

Marine Animals

• Most marine invertebrates are osmoconformers• Most marine vertebrates and some invertebrates

are osmoregulators• Marine bony fishes are hypoosmotic to seawater• They lose water by osmosis and gain salt by

diffusion and from food• They balance water loss by drinking seawater

and excreting salts

© 2011 Pearson Education, Inc.

Figure 44.3

(a) Osmoregulation in a marine fish (b) Osmoregulation in a freshwater fish

Gain of waterand salt ionsfrom food

Excretionof salt ionsfrom gills

Osmotic waterloss through gillsand other partsof body surface

Gain of waterand salt ionsfrom drinkingseawater

Excretion of salt ions andsmall amounts of water inscanty urine from kidneys

Gain of waterand some ionsin food

Uptake ofsalt ionsby gills

Osmotic watergain throughgills and otherparts of bodysurface

Excretion of salt ions andlarge amounts of water indilute urine from kidneys

Key

Water

Salt

(a) Osmoregulation in a marine fish

Gain of waterand salt ionsfrom food

Excretionof salt ionsfrom gills

Osmotic waterloss through gillsand other partsof body surface

Gain of waterand salt ionsfrom drinkingseawater

Excretion of salt ions andsmall amounts of water inscanty urine from kidneys

Key

Water

Salt

Figure 44.3a

Freshwater Animals

• Freshwater animals constantly take in water by osmosis from their hypoosmotic environment

• They lose salts by diffusion and maintain water balance by excreting large amounts of dilute urine

• Salts lost by diffusion are replaced in foods and by uptake across the gills

© 2011 Pearson Education, Inc.

Figure 44.3b

(b) Osmoregulation in a freshwater fish

Gain of waterand some ionsin food

Uptake ofsalt ionsby gills

Osmotic watergain throughgills and otherparts of bodysurface

Excretion of salt ions andlarge amounts of water indilute urine from kidneys

Key

Water

Salt