Biology Notes

Life in Taiao

Definitions:

• Cell - A cell is the smallest unit of organisation in living things.

• Biological Kingdom - A biological kingdom is the way science classifies living things based on the ancestor over the course of evolution.

• Ecosystem - Interactions of organisms in a specific area with each other and their non-living environment.

• Habitat - Where an organism lives.

• Population - A group of organisms in a specific area of the same species.

• Community - All of the living organisms that live in a specific area.

• Adaptation - A feature or trait that an organism has that helps it survive in its habitat.

• Food Chain - A food chain shows the flow of energy between organisms in a habitat.

• Biodiversity - The variety of plant and animal life in the world or in a particular habitat.

• Endemic - A species that is endemic is one that is only found in a particular place.

• Native - A species that is native is one that is originally from a particular place but can be found in other places.

• Extinct - No more of the species left existence.

• Endangered - A species close to being extinct due to low numbers.

• At Risk - A species close to being endangered.

• Deforestation - Removal of forested areas.

• Invasive Predators - Newly introduced predators that prey on our endemic species.

• Competition - When species are fighting for resources such as food and space.

• Overhunting - To hunt a species to an excessive degree, where the population becomes too low.

Cell Theory

• All living things are made up of 1 or more cells.

• All cells come from a pre-existing cell.

• Something is an organism if it follows the 7 life processes.

7 Life Processes (Mrs Gren)

• Movement - Organisms can change the position of their body.

• Respiration - The breakdown of glucose to produce energy.

• Sensitivity - The ability to respond to the environment.

• Growth - Organisms can increase the number of cells and the size of their cells.

• Reproduction - The process of off-spring to continue the species

• Excretion - The removal of waste from an organism.

• Nutrition - The process where an organism consumes food to use energy.

Animal and Plant cell labelling

• Cell membrane - Transport material in and out of the cell (Animal and Plant)

• Nucleus - Contains genetics of the cell (Animal and plant)

• Mitochondria - Where respiration occurs (Animal and plant)

• Cytoplasm - Suspends organelles 3d space (Animal and plant)

• Chloroplasts - Site of photosynthesis (Plant only)

• Vocuole - Stores nutrients and water for the cell. (Plant only)

• Cell wall - Provides structural support. (Plant only)

Why do you think plant cells need a cell wall and animal cells do not?

Plant cells have a cell wall to protect them from a harser environment, while animals are usually able to take cover or escape these environments.

5 Biological Kingdoms

A biological kingdom is the way science classifies living things based on the ancestor over the course of evolution.

• Animalia - Multicellular organism that consumes other living things for nutrition.

• Plantae - Multicellular organisms that photosynthesis.

• Fungi - Multicellular organism that breaks down other living things.

• Protista - Small, single-cell organism with a nucleus.

• Monera/Prokaryote - Small, single cell organism with no nucleus.

Adaptation

A feature or trait that an organism has that helps it survive in its habitat.

(Makes species more likely to reproduce)

• Structural - A physical trait of an organism’s body.

• Physiological - A body process

• Behavioural - When an organism changes their behaviour to help them survive.

Food Chains

A food chain shows the flow of energy between organisms in a habitat.

1. The arrow in a food chain shows the flow of energy.

2. This means the arrow points from prey to predator.

• Producer - an organism that manufactures food by utilising energy from the sun.

• Consumer - an organism that consumes others, they cannot make their own food.

• Primary consumer (Herbivore) - an organism that consumes plants (producers).

• Secondary consumer (Carnivore) - consumes Herbivore (primary consumers).

• Tertiary consumers (carnivores) - consumes carnivores (secondary consumers).

Energy Transfer through the Food Chain

Between levels in the food chain, only ~10% of energy is transferred to the consumers (as ~ 90% of their energy carries out their life processes). This means the energy transfers get smaller as you move up the trophic levels.

Food Web

Shows all the food chains (energy flows) within an ecosystem, and represents all the different feeding relationships.

Why are there only 4-5 trophic levels in each food chain?

The loss of energy between each trophic level is so great that little energy remains after 4-5 levels – therefore not enough energy for a 5-6th trophic level to exist on.

Biodiversity

The variety of plant and animal life in the world or in a particular habitat.

Biodiversity keeps ecosystems healthy by ensuring there are various species to support and balance each other. If one species declines, others can take its place, preventing ecosystem collapse. This variety helps ecosystems survive climate changes and diseases.

Gondwanaland

NZ split away from Gondawanaland ~80 million years ago. Because of this early split, NZ has an extremely unique ecosystem.

NZ only has 2 native mammals (bats) so most NZ birds took the role of a mammal as there were no land predators to avoid. Lots of birds evolved to be flightless.

Microbes

Definitions:

• Microorganism - A microorganism is a very tiny organism that can only be viewed (most of the time) under a microscope.

• Pathogens - A disease causing microorganisms or microbes.

Microbes:

A microorganism is a very tiny organism that can only be viewed (most of the time) under a microscope.

Includes - Bacteria, Fungi, Viruses

• Bacteria - Unicellular organism in monera/prokaryote kingdom due to having no nucleus.

• Fungi - Microorganisms in the fungi kingdom, includes: yeast, moulds, and mushrooms. (Often grow large enough to see with the naked eye).

• Virus - A non-living microorganism consisting of nuclear material in a protein coat.

Reproduction:

Bacteria, binary fission

1. Cell gets bigger

2. DNA duplicates

3. Cell membrane pinches cytoplasm

4. The cell splits into 2 identical cells

Fungi, spores

1. Hyphae grow upwards and produce a swelling called sporangia.

2. Spores grow in the sporangia, which burst and release spores.

3. Spores land on a food source with moisture to germinate and grow.

Virus, Viral Reproduction

1. A virus attaches to the host cell.

2. A virus injects DNA into the cell.

3. Viral DNA takes over the nucleus and instructs it to make DNA copies.

4. Viruses assemble until the cell is packed full.

5. The cell bursts and viruses are released to continue the process.

Helpful vs Harmful:

Microbes can be both helpful and harmful.

Helpful:

• Yeast - Fungi used in baking fermentation creates CO2 which helps things rise.

• Antibiotics - Special fungi that kills specific bacteria.

Harmful:

A harmful microbe is something that causes diseases (a pathogen).

Most viruses are considered pathogens as they have to destroy cells to survive.

Antibiotics:

A chemical produced by fungi that inhibits/stops the growth and reproduction of bacteria. (Antibiotics have no effect on viruses).

Antibiotics Resistance

1. A large number of bacteria with a few resistance bacteria.

2. Antibiotics kill the majority of the bacteria over time, and resistance bacteria live.

3. If full course is not completed resistance bacteria reproduce.

4. Antibiotics do not work, so the next time you're sick is dangerous.