LIFE ON EARTH_original

LIFE ON EARTH

UNIT 5

1. THE CONDITIONS NECESSARY FOR LIFE

Our planet meets the conditions required for living beings to develop

Why is Earth an ideal place for life?

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What are the conditions required for living beings to develop?

MILD TEMPERATURES: 15º average. Allows presence of liquid water.LIQUID WATER: It's an essential part of all living beings and helps regulate the Earth's temperature VITAL GASES: Oxygen (respiration) and carbon dioxide (photosynthesis) PROTECTION AGAINST HARMFUL RADIATIONS FROM THE SUN: They can kill cells A VARIETY OF PLACES TO LIVE

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2. WHAT ARE LIVING BEINGS LIKE?

We are a big beautiful family!!

All living things share three fundamental characteristics

With some dangerous members...

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All living beings...

... are made up of cells

... have a similar chemical composition

... carry out the three living functions

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All living beings have a similar chemical composition

All matter in the universe is made up of atoms (elements) that join together forming molecules. Living beings are made up of BIOMOLECULES: - INORGANIC BIOMOLECULES are found in both living and non living things. They are water and minerals. - ORGANIC BIOMOLECULES are only found in living beings. They are carbohydrates, lipids, proteins and nucleic acids.

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All living beings are made up of cells

CELLS are the smallest units of a living organism capable of carrying out the three vital functions.

Multicellular organisms are composed of more than one cell (up to millions)

Unicellular organisms are composed of one single cell

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All living beings carry out the three vital functions

REPRODUCTION

INTERACTION

NUTRITION

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3. LIVING BEINGS ARE MADE UP OF CELLS

All cells contain three common structures... but there are some differences among the 3 main types of cells

All other organisms (including us) are made up of EUKARYOTIC CELLS

BACTERIA are made up of PROKARYOTIC CELLS

DISCOVER

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4. LIVING BEINGS PERFORM VITAL FUNCTIONS

REPRODUCTION

NUTRITION

INTERACTION

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NUTRITION is the set of processes through which living beings obtain the substances they need in order to grow, repair damaged structures and obtain energy.The processes of nutrition are:

Distributing substances

Obtaining nutrients

Respiration

Excretion

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NUTRIENTS are the biomolecules that living beings need to take from the environment. - AUTOTROPHIC organisms can build up their own organic biomolecules. Photosynthesis is a type of autotrophic nutrition.- HETEROTROPHIC organisms must take all nutrients (organic and inorganic) from the environment. They actually "eat" other living beings.

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RESPIRATION is a process that takes place inside the cells, in which O2 is used, energyis obtained from nutrients and CO2 is released.

We all do respiration!!(only a few bacteria don't)

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Substances need to be exchanged with the environment and distributed!!

But somewhat more complicated for us!

That's easy for guys like us!

By performing the vital functions, cells produce lots of waste that should be eliminated from the organism.

Time to take out the garbage!

Oh yeah!

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INTERACTION is the function that allows living beings to receive information both from the environment and from within and react to it appropriately. There are three steps in interaction:1. Stimuli: Any internal or external information that is perceived. 2. Processing: The information is processed in order to prepare a coordinated response. 3. Response: A suitable response is executed.

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REPRODUCTION is the capacity of all living beings to give life to other beings that are similar or identical to them. Reproduction can be:

ASEXUAL

SEXUAL

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ASEXUAL REPRODUCTION

Only ONE individual is involved

Offspring are identical (clones) to the only parent.

Typically in unicellular organisms, it also happens in many multicellular ones.

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SEXUAL REPRODUCTION

TWO individuals are required

They produce cells called gametes: OVULE and SPERMATOZOON

Offspring develop from a single cell (ZYGOTE) formed from the fusion of the two gametesOffspring share characteristics of both parents, and can show new ones Typical reproduction for most multicellular organisms

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5. THE SCIENCE OF CLASSIFYING LIFE

We need to classify living things in order to study them. That's what TAXONOMY does!

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Scientists classify living beings in accordance with natural criteria (natural characteristics that they have in common).TAXA (sing. TAXON) are the groups into which we classify living organisms

What is a SPECIES?

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A SPECIES is a group of individuals with similar characteristics that can interbreed and produce fertile offspring.

Scientists assign each species a scientific name, which is the same all over the world. It is composed of two words: Genus + species

Homo sapiens

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6. THE KINGDOMS OF LIFE

Living beings are divided into groups depending on their level of complexity

protoctista

THE FIVE (or six) KINGDOMS

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THE SIX KINGDOMS (once five)

Domain Archaea

Domain Bacteria

Domain Eukarya

protoctista

Originally Kingdom Monera

ARCHAEA and BACTERIACells: ProkaryoticOrganisation: Unicellular Nutrition: Heterotrophic / autotrophic

PROTOCTISTA Cells: Eukaryotic Organisation: Uni / Multicellular Nutrition: Heterotrophic (protozoa) / autotrophic (algae)

FUNGI Cells: Eukaryotic Organisation: Uni / Multicellular Nutrition: Heterotrophic

PLANTS Cells: Eukaryotic Organisation: Multicellular Nutrition: Autotrophic

ANIMALS Cells: Eukaryotic Organisation: Multicellular Nutrition: Heterotrophic

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