Factors affecting population size - Miss Hanson's Biology...
Transcript of Factors affecting population size - Miss Hanson's Biology...
![Page 1: Factors affecting population size - Miss Hanson's Biology ...hansonbiology.weebly.com/uploads/1/7/7/8/17781999/sg_bio_b_how_it... · The Biosphere Investigating an ecosystem ... making](https://reader035.fdocuments.us/reader035/viewer/2022081605/5a9f01437f8b9a62178c2c30/html5/thumbnails/1.jpg)
Biosphere
SG Biology
How it works?
![Page 2: Factors affecting population size - Miss Hanson's Biology ...hansonbiology.weebly.com/uploads/1/7/7/8/17781999/sg_bio_b_how_it... · The Biosphere Investigating an ecosystem ... making](https://reader035.fdocuments.us/reader035/viewer/2022081605/5a9f01437f8b9a62178c2c30/html5/thumbnails/2.jpg)
The Biosphere Investigating an ecosystem
Sampling and other measurement techniques applied to the investigation of an ecosystem.
How it works Components of an ecosystem,
energy flow,
population growth,
controlling factors.
Control and management Intervention in the natural balance of an ecosystem;
using understanding to manage ecosystems.
![Page 3: Factors affecting population size - Miss Hanson's Biology ...hansonbiology.weebly.com/uploads/1/7/7/8/17781999/sg_bio_b_how_it... · The Biosphere Investigating an ecosystem ... making](https://reader035.fdocuments.us/reader035/viewer/2022081605/5a9f01437f8b9a62178c2c30/html5/thumbnails/3.jpg)
Identification
Think of a species (plant or animal)
Write down a description of your
species on a piece of card.
Exchange the card with another
member of the class.
Could they identify the species you
have described?
![Page 4: Factors affecting population size - Miss Hanson's Biology ...hansonbiology.weebly.com/uploads/1/7/7/8/17781999/sg_bio_b_how_it... · The Biosphere Investigating an ecosystem ... making](https://reader035.fdocuments.us/reader035/viewer/2022081605/5a9f01437f8b9a62178c2c30/html5/thumbnails/4.jpg)
Identification keys
Identification keys help us to identify plants and animals. Have a look at the samples of keys available in class.
The two types of key you could use are: Numerical key
Branched key
Complete the worksheet on identification keys
![Page 5: Factors affecting population size - Miss Hanson's Biology ...hansonbiology.weebly.com/uploads/1/7/7/8/17781999/sg_bio_b_how_it... · The Biosphere Investigating an ecosystem ... making](https://reader035.fdocuments.us/reader035/viewer/2022081605/5a9f01437f8b9a62178c2c30/html5/thumbnails/5.jpg)
Food Chains
Watch the Scientific Eye video
making notes on food chains, and
factors affecting populations.
![Page 6: Factors affecting population size - Miss Hanson's Biology ...hansonbiology.weebly.com/uploads/1/7/7/8/17781999/sg_bio_b_how_it... · The Biosphere Investigating an ecosystem ... making](https://reader035.fdocuments.us/reader035/viewer/2022081605/5a9f01437f8b9a62178c2c30/html5/thumbnails/6.jpg)
Food Chains and Food
Webs
Environment and Feeding
![Page 7: Factors affecting population size - Miss Hanson's Biology ...hansonbiology.weebly.com/uploads/1/7/7/8/17781999/sg_bio_b_how_it... · The Biosphere Investigating an ecosystem ... making](https://reader035.fdocuments.us/reader035/viewer/2022081605/5a9f01437f8b9a62178c2c30/html5/thumbnails/7.jpg)
Definitions Herbivore:
An animal that eats grass and other green plants in a food chain;
Carnivore: A flesh-eating animal.
Prey: An animal hunted or caught for food
Predator: An organism that lives by preying on other organisms.
![Page 8: Factors affecting population size - Miss Hanson's Biology ...hansonbiology.weebly.com/uploads/1/7/7/8/17781999/sg_bio_b_how_it... · The Biosphere Investigating an ecosystem ... making](https://reader035.fdocuments.us/reader035/viewer/2022081605/5a9f01437f8b9a62178c2c30/html5/thumbnails/8.jpg)
Definitions Primary consumer:
An animal that eats grass and other green plants in a food chain; an herbivore.
Secondary consumer: An animal that feeds on smaller plant-eating animals in a food chain.
tertiary consumer: An animal that feeds on secondary consumers in a food chain.
Population: All the organisms of the same species living in the same place at the same time.
![Page 9: Factors affecting population size - Miss Hanson's Biology ...hansonbiology.weebly.com/uploads/1/7/7/8/17781999/sg_bio_b_how_it... · The Biosphere Investigating an ecosystem ... making](https://reader035.fdocuments.us/reader035/viewer/2022081605/5a9f01437f8b9a62178c2c30/html5/thumbnails/9.jpg)
Food Chains Food chains are one way of showing how
organisms interact. For example:
Grass Rabbit Fox
The arrows represent the flow of energy
(food) between organisms, it points from
the eaten to the eater.
![Page 10: Factors affecting population size - Miss Hanson's Biology ...hansonbiology.weebly.com/uploads/1/7/7/8/17781999/sg_bio_b_how_it... · The Biosphere Investigating an ecosystem ... making](https://reader035.fdocuments.us/reader035/viewer/2022081605/5a9f01437f8b9a62178c2c30/html5/thumbnails/10.jpg)
All food chains start with plants, they use sunlight during photosynthesis to build up food (energy) stores, these are then passed on to animals.
Important terms: Plants are producers because they produce their own food
Animals are consumers because they eat food to obtain energy.
![Page 11: Factors affecting population size - Miss Hanson's Biology ...hansonbiology.weebly.com/uploads/1/7/7/8/17781999/sg_bio_b_how_it... · The Biosphere Investigating an ecosystem ... making](https://reader035.fdocuments.us/reader035/viewer/2022081605/5a9f01437f8b9a62178c2c30/html5/thumbnails/11.jpg)
There are 3 types of consumer Herbivores eat plants
Carnivores eat other animals
Omnivores eat plants and animals
Organisms that breakdown dead plants and animals are called decomposers, e.g. fungi, bacteria and worms
Producer primary secondary tertiary consumer consumer consumer
PLANTS HERBIVORE CARNIVORE TOP CARNIVORE
![Page 12: Factors affecting population size - Miss Hanson's Biology ...hansonbiology.weebly.com/uploads/1/7/7/8/17781999/sg_bio_b_how_it... · The Biosphere Investigating an ecosystem ... making](https://reader035.fdocuments.us/reader035/viewer/2022081605/5a9f01437f8b9a62178c2c30/html5/thumbnails/12.jpg)
Food Webs
When several food chains in a
habitat are studied, some organisms
appear in more than one.
This is because most animals eat
more than one type of food.
If food chains in a habitat are linked,
they form a FOOD WEB.
![Page 13: Factors affecting population size - Miss Hanson's Biology ...hansonbiology.weebly.com/uploads/1/7/7/8/17781999/sg_bio_b_how_it... · The Biosphere Investigating an ecosystem ... making](https://reader035.fdocuments.us/reader035/viewer/2022081605/5a9f01437f8b9a62178c2c30/html5/thumbnails/13.jpg)
Food web for a single tree
![Page 14: Factors affecting population size - Miss Hanson's Biology ...hansonbiology.weebly.com/uploads/1/7/7/8/17781999/sg_bio_b_how_it... · The Biosphere Investigating an ecosystem ... making](https://reader035.fdocuments.us/reader035/viewer/2022081605/5a9f01437f8b9a62178c2c30/html5/thumbnails/14.jpg)
Which are the primary and secondary
consumers in this photograph?
![Page 15: Factors affecting population size - Miss Hanson's Biology ...hansonbiology.weebly.com/uploads/1/7/7/8/17781999/sg_bio_b_how_it... · The Biosphere Investigating an ecosystem ... making](https://reader035.fdocuments.us/reader035/viewer/2022081605/5a9f01437f8b9a62178c2c30/html5/thumbnails/15.jpg)
Competing for the same
niche
![Page 16: Factors affecting population size - Miss Hanson's Biology ...hansonbiology.weebly.com/uploads/1/7/7/8/17781999/sg_bio_b_how_it... · The Biosphere Investigating an ecosystem ... making](https://reader035.fdocuments.us/reader035/viewer/2022081605/5a9f01437f8b9a62178c2c30/html5/thumbnails/16.jpg)
Biosphere
How it works?
Populations
Adaptations
![Page 17: Factors affecting population size - Miss Hanson's Biology ...hansonbiology.weebly.com/uploads/1/7/7/8/17781999/sg_bio_b_how_it... · The Biosphere Investigating an ecosystem ... making](https://reader035.fdocuments.us/reader035/viewer/2022081605/5a9f01437f8b9a62178c2c30/html5/thumbnails/17.jpg)
Factors affecting population size
![Page 18: Factors affecting population size - Miss Hanson's Biology ...hansonbiology.weebly.com/uploads/1/7/7/8/17781999/sg_bio_b_how_it... · The Biosphere Investigating an ecosystem ... making](https://reader035.fdocuments.us/reader035/viewer/2022081605/5a9f01437f8b9a62178c2c30/html5/thumbnails/18.jpg)
Populations
A population is a group of
individuals of the same species living
in a particular habitat at the same
time.
The number of individuals present in
the population will depend on how
they can interact with two types of
factor.
![Page 19: Factors affecting population size - Miss Hanson's Biology ...hansonbiology.weebly.com/uploads/1/7/7/8/17781999/sg_bio_b_how_it... · The Biosphere Investigating an ecosystem ... making](https://reader035.fdocuments.us/reader035/viewer/2022081605/5a9f01437f8b9a62178c2c30/html5/thumbnails/19.jpg)
Populations
Living factors – food, disease,
predation, mates, effects of
humans, and competition
Non-living factors – water, oxygen,
carbon dioxide, temperature and
light
![Page 20: Factors affecting population size - Miss Hanson's Biology ...hansonbiology.weebly.com/uploads/1/7/7/8/17781999/sg_bio_b_how_it... · The Biosphere Investigating an ecosystem ... making](https://reader035.fdocuments.us/reader035/viewer/2022081605/5a9f01437f8b9a62178c2c30/html5/thumbnails/20.jpg)
Competition for Resources Plants and animals compete for resources.
Plants often compete with each other for space, and for nutrients and water from the soil.
Animals often compete with each other for space, water and food.
![Page 21: Factors affecting population size - Miss Hanson's Biology ...hansonbiology.weebly.com/uploads/1/7/7/8/17781999/sg_bio_b_how_it... · The Biosphere Investigating an ecosystem ... making](https://reader035.fdocuments.us/reader035/viewer/2022081605/5a9f01437f8b9a62178c2c30/html5/thumbnails/21.jpg)
Competition for Resources
There are two types of competition: Intra-specific – competition between individuals of the same species
Red deer stags fight to
mate with the females
Boobies compete for
nesting space
![Page 22: Factors affecting population size - Miss Hanson's Biology ...hansonbiology.weebly.com/uploads/1/7/7/8/17781999/sg_bio_b_how_it... · The Biosphere Investigating an ecosystem ... making](https://reader035.fdocuments.us/reader035/viewer/2022081605/5a9f01437f8b9a62178c2c30/html5/thumbnails/22.jpg)
Plants compete for space, light,
water and nutrients.
Competition for Resources
Inter-specific – competition between individuals of different species.
Garden birds compete for
food in winter
![Page 23: Factors affecting population size - Miss Hanson's Biology ...hansonbiology.weebly.com/uploads/1/7/7/8/17781999/sg_bio_b_how_it... · The Biosphere Investigating an ecosystem ... making](https://reader035.fdocuments.us/reader035/viewer/2022081605/5a9f01437f8b9a62178c2c30/html5/thumbnails/23.jpg)
Factors affecting population size
A population is a group of individuals of the same species living in a particular habitat.
Births and immigration increase the size of a population.
Deaths and emigration decrease the size of a population.
![Page 24: Factors affecting population size - Miss Hanson's Biology ...hansonbiology.weebly.com/uploads/1/7/7/8/17781999/sg_bio_b_how_it... · The Biosphere Investigating an ecosystem ... making](https://reader035.fdocuments.us/reader035/viewer/2022081605/5a9f01437f8b9a62178c2c30/html5/thumbnails/24.jpg)
Factors affecting population size
The size of a population, may also be affected by:
The total amount of food and water available, if food supply is low, then individuals will compete for them.
Oxygen shortage can limit numbers in a population that lives in water.
Poisons can build up in the environment and limit population growth.
![Page 25: Factors affecting population size - Miss Hanson's Biology ...hansonbiology.weebly.com/uploads/1/7/7/8/17781999/sg_bio_b_how_it... · The Biosphere Investigating an ecosystem ... making](https://reader035.fdocuments.us/reader035/viewer/2022081605/5a9f01437f8b9a62178c2c30/html5/thumbnails/25.jpg)
Factors affecting population size
List continued from previous page:
Predation will limit the prey population.
Disease can spread quickly through
large populations.
Climate – drought, flood and storms all
affect population numbers.
Lack of shelter
Competition for light
![Page 26: Factors affecting population size - Miss Hanson's Biology ...hansonbiology.weebly.com/uploads/1/7/7/8/17781999/sg_bio_b_how_it... · The Biosphere Investigating an ecosystem ... making](https://reader035.fdocuments.us/reader035/viewer/2022081605/5a9f01437f8b9a62178c2c30/html5/thumbnails/26.jpg)
Population Graphs
For one species in good conditions
1
2
3
4
time
Number of
individuals
![Page 27: Factors affecting population size - Miss Hanson's Biology ...hansonbiology.weebly.com/uploads/1/7/7/8/17781999/sg_bio_b_how_it... · The Biosphere Investigating an ecosystem ... making](https://reader035.fdocuments.us/reader035/viewer/2022081605/5a9f01437f8b9a62178c2c30/html5/thumbnails/27.jpg)
For one population in good condition
1. Slow increase as only a few individuals.
2. Sharp increase, good conditions for growth
3. Some factors start to slow down increase (e.g. lack of food).
4. Stable population (birth rate = death rate)
![Page 28: Factors affecting population size - Miss Hanson's Biology ...hansonbiology.weebly.com/uploads/1/7/7/8/17781999/sg_bio_b_how_it... · The Biosphere Investigating an ecosystem ... making](https://reader035.fdocuments.us/reader035/viewer/2022081605/5a9f01437f8b9a62178c2c30/html5/thumbnails/28.jpg)
Predator-prey relationships
Animals that kill and eat other animals are called predators. The animals that they eat are called prey.
Predators are usually bigger and fewer in number than their prey.
List five things that make a good predator:
List five ways prey have adapted escape from predators:
![Page 29: Factors affecting population size - Miss Hanson's Biology ...hansonbiology.weebly.com/uploads/1/7/7/8/17781999/sg_bio_b_how_it... · The Biosphere Investigating an ecosystem ... making](https://reader035.fdocuments.us/reader035/viewer/2022081605/5a9f01437f8b9a62178c2c30/html5/thumbnails/29.jpg)
The graph shows the relationship
between a predator and its prey.
![Page 30: Factors affecting population size - Miss Hanson's Biology ...hansonbiology.weebly.com/uploads/1/7/7/8/17781999/sg_bio_b_how_it... · The Biosphere Investigating an ecosystem ... making](https://reader035.fdocuments.us/reader035/viewer/2022081605/5a9f01437f8b9a62178c2c30/html5/thumbnails/30.jpg)
List what is happening in each of
the stages 1 – 5 on the predator
prey graph.
1. The prey has plenty of food. It breeds and increases in number.
2. The increase in prey means that there is more food for the predator. So the predator breeds and increases in number.
3. There are now lots of predators so more prey will be eaten. The number of prey goes down.
![Page 31: Factors affecting population size - Miss Hanson's Biology ...hansonbiology.weebly.com/uploads/1/7/7/8/17781999/sg_bio_b_how_it... · The Biosphere Investigating an ecosystem ... making](https://reader035.fdocuments.us/reader035/viewer/2022081605/5a9f01437f8b9a62178c2c30/html5/thumbnails/31.jpg)
Predator prey graph 4. There are now less prey for the predator
to feed on. Food will be scarce and
many predators starve.
5. With fewer predators, more prey survive
to breed. The prey numbers increase
The cycle continues…
![Page 32: Factors affecting population size - Miss Hanson's Biology ...hansonbiology.weebly.com/uploads/1/7/7/8/17781999/sg_bio_b_how_it... · The Biosphere Investigating an ecosystem ... making](https://reader035.fdocuments.us/reader035/viewer/2022081605/5a9f01437f8b9a62178c2c30/html5/thumbnails/32.jpg)
Adaptation
The Biosphere
How it works?
![Page 33: Factors affecting population size - Miss Hanson's Biology ...hansonbiology.weebly.com/uploads/1/7/7/8/17781999/sg_bio_b_how_it... · The Biosphere Investigating an ecosystem ... making](https://reader035.fdocuments.us/reader035/viewer/2022081605/5a9f01437f8b9a62178c2c30/html5/thumbnails/33.jpg)
Learning Outcomes
To explain the terms ecosystem,
habitat and community.
To understand that physical factors
affect animals living in an ecosystem
To be able to explain how animals
are adapted for survival in arctic
and desert conditions.
![Page 34: Factors affecting population size - Miss Hanson's Biology ...hansonbiology.weebly.com/uploads/1/7/7/8/17781999/sg_bio_b_how_it... · The Biosphere Investigating an ecosystem ... making](https://reader035.fdocuments.us/reader035/viewer/2022081605/5a9f01437f8b9a62178c2c30/html5/thumbnails/34.jpg)
What is an Ecosystem?
![Page 35: Factors affecting population size - Miss Hanson's Biology ...hansonbiology.weebly.com/uploads/1/7/7/8/17781999/sg_bio_b_how_it... · The Biosphere Investigating an ecosystem ... making](https://reader035.fdocuments.us/reader035/viewer/2022081605/5a9f01437f8b9a62178c2c30/html5/thumbnails/35.jpg)
The Environment An ecosystem is an environment where living organisms can survive.
The environment is made up of lots of different ecosystems, such as seashore, a wood or a river.
Each ecosystem is made up Habitats and Communities
Habitat - This is the place where the organisms live. It has the conditions that they need to survive.
Community – all the living organisms that live in the habitat.
![Page 36: Factors affecting population size - Miss Hanson's Biology ...hansonbiology.weebly.com/uploads/1/7/7/8/17781999/sg_bio_b_how_it... · The Biosphere Investigating an ecosystem ... making](https://reader035.fdocuments.us/reader035/viewer/2022081605/5a9f01437f8b9a62178c2c30/html5/thumbnails/36.jpg)
Physical Factors Each ecosystem has a set of environmental factors.
Availability of water
Temperature - Few living organisms can grow outside the range of 0oC to 40oC.
amount of Light - photosynthesis in plants, animals need light for visibility.
Availability of carbon dioxide and oxygen
These factors vary according to the time of day and the time of year.
![Page 37: Factors affecting population size - Miss Hanson's Biology ...hansonbiology.weebly.com/uploads/1/7/7/8/17781999/sg_bio_b_how_it... · The Biosphere Investigating an ecosystem ... making](https://reader035.fdocuments.us/reader035/viewer/2022081605/5a9f01437f8b9a62178c2c30/html5/thumbnails/37.jpg)
Adaptations
Living things adapt to their
environment.
Watch the video clip, and then try
to fill in the table explaining how the
creature is adapted to it’s
environment.
![Page 38: Factors affecting population size - Miss Hanson's Biology ...hansonbiology.weebly.com/uploads/1/7/7/8/17781999/sg_bio_b_how_it... · The Biosphere Investigating an ecosystem ... making](https://reader035.fdocuments.us/reader035/viewer/2022081605/5a9f01437f8b9a62178c2c30/html5/thumbnails/38.jpg)
Adaptations in different
animals
Look at the animals on the
worksheet, for each one try to give
where it lives and an example of
how it is adapted for survival in its
environment.
![Page 39: Factors affecting population size - Miss Hanson's Biology ...hansonbiology.weebly.com/uploads/1/7/7/8/17781999/sg_bio_b_how_it... · The Biosphere Investigating an ecosystem ... making](https://reader035.fdocuments.us/reader035/viewer/2022081605/5a9f01437f8b9a62178c2c30/html5/thumbnails/39.jpg)
![Page 40: Factors affecting population size - Miss Hanson's Biology ...hansonbiology.weebly.com/uploads/1/7/7/8/17781999/sg_bio_b_how_it... · The Biosphere Investigating an ecosystem ... making](https://reader035.fdocuments.us/reader035/viewer/2022081605/5a9f01437f8b9a62178c2c30/html5/thumbnails/40.jpg)
Pupil Activity
Surviving in different environments.
Read all information carefully
Answer questions 1 - 9
![Page 41: Factors affecting population size - Miss Hanson's Biology ...hansonbiology.weebly.com/uploads/1/7/7/8/17781999/sg_bio_b_how_it... · The Biosphere Investigating an ecosystem ... making](https://reader035.fdocuments.us/reader035/viewer/2022081605/5a9f01437f8b9a62178c2c30/html5/thumbnails/41.jpg)
Camel
designed for desert conditions
Big flat feet stop it sinking into the sand.
Short hair underneath the camel
lets heat escape.
Coarse wool on top of its body protects the camel from the sun.
A camel’s hump is a fat store. It can break down fat to release water.
A camel can drink large amounts of water. Its mouth is tough so that it can eat thorny plants like cacti.
![Page 42: Factors affecting population size - Miss Hanson's Biology ...hansonbiology.weebly.com/uploads/1/7/7/8/17781999/sg_bio_b_how_it... · The Biosphere Investigating an ecosystem ... making](https://reader035.fdocuments.us/reader035/viewer/2022081605/5a9f01437f8b9a62178c2c30/html5/thumbnails/42.jpg)
Adaptations to water loss
a cactus in the desert Leaves reduced to spines – to reduce water loss
through stoma
Swollen stem
stores water
Wide spread root
systems to increase
surface area for absorption.
![Page 43: Factors affecting population size - Miss Hanson's Biology ...hansonbiology.weebly.com/uploads/1/7/7/8/17781999/sg_bio_b_how_it... · The Biosphere Investigating an ecosystem ... making](https://reader035.fdocuments.us/reader035/viewer/2022081605/5a9f01437f8b9a62178c2c30/html5/thumbnails/43.jpg)
Camel – designed for desert conditions
Big flat feet stop it sinking into the sand.
Short hair underneath the camel
lets heat escape.
Coarse wool on top of its body protects the camel from the sun.
A camel’s hump is a fat store. It can break down fat to release water.
A camel can drink large amounts of water. Its mouth is tough so that it can eat thorny plants like cacti.
![Page 44: Factors affecting population size - Miss Hanson's Biology ...hansonbiology.weebly.com/uploads/1/7/7/8/17781999/sg_bio_b_how_it... · The Biosphere Investigating an ecosystem ... making](https://reader035.fdocuments.us/reader035/viewer/2022081605/5a9f01437f8b9a62178c2c30/html5/thumbnails/44.jpg)
Adaptations to water loss - a cactus in the desert
Leaves reduced to spines – to reduce water
loss through stoma
Swollen stem
stores water
Wide spread root
systems to increase
surface area for absorption.
![Page 45: Factors affecting population size - Miss Hanson's Biology ...hansonbiology.weebly.com/uploads/1/7/7/8/17781999/sg_bio_b_how_it... · The Biosphere Investigating an ecosystem ... making](https://reader035.fdocuments.us/reader035/viewer/2022081605/5a9f01437f8b9a62178c2c30/html5/thumbnails/45.jpg)
Class activity To draw labelled diagrams of a cactus, a camel and a polar bear which explain how they are adapted to their environment.
Use one side of your exercise book for each diagram, and labels.
Use the handouts to help you with the labels.
Commendations will be awarded for exceptional work!
![Page 46: Factors affecting population size - Miss Hanson's Biology ...hansonbiology.weebly.com/uploads/1/7/7/8/17781999/sg_bio_b_how_it... · The Biosphere Investigating an ecosystem ... making](https://reader035.fdocuments.us/reader035/viewer/2022081605/5a9f01437f8b9a62178c2c30/html5/thumbnails/46.jpg)
Pupil Activity - extension
Environmental factors affecting life
Read all the information supplied on
the sheet carefully.
Answer questions 1 – 11 in full
sentences.