Science 9: Unit 1 - Biodiversity Notes

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Science 9: Unit 1 - Biodiversity

Topic 1.1 - Variety of Life on Earth

Biodiversity refers to the variation in nature and how the interactions between living things are vital.

All living things have these five characteristics:

- Ability to reproduce

- Made up of cells

- Need energy

- Grow and develop

- Have adaptations to survive

Elements of Biodiversity:

Species: A group of organisms that are similar and can reproduce with each other

Ecosystem: The interactions of living things in a certain place Eg. Deserts, forests

Genetic Diversity: Genetic varieties of a species Eg. Size or shape of an animal in a species

Species Diversity: Number of species in an ecosystem

Ecosystem Diversity: Variation among landscapes and communities

There is more diversity at the equator because of the warmer and calmer climates.

Classifying Organisms:

All organisms are classified by Kingdom, Phylum, Class, Order, Family, Genus, Species

Remember it using "Killing People 'Cause Orphans Froze Grandma Stephanie"

Eg. A Dog

K: Animalia

P: Chordata

C: Mammalia

O: Carnivora

F: Canidae

G: Canis

Species: Canis Familiaris

The five Kingdoms: Plantae, Animalia, Monera, Protista, Fungae

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Science 9: Unit 1 - Biodiversity

Topic 1.2 - Relationships between Species

Competition:

Intra-species Competition -

Competition between organisms of the same species

Interspecies Competition -

Competition between organisms of different species

Population: A group of the same species in the same area

Community: A group of populations of different species

Niche: Describes the inter-relationships of a species

- Broad Niche: Can eat many things to survive, high population, little density, "Generalists"

- Narrow Niche: Only has adaptations to eat few things to survive, low population, high density, "Specialists", only in tropical regions

Resource Partitioning: Competing for resources by accessing it differently from the same source

Symbiosis: Two or more organisms living in a long term relationship

- Mutualism - Both organisms benefit from the relationship

- Parasitism - One organism is harmed and the other is benefitted

- Commensalism - One organism is benefitted and the other isn't affected

Interdependence: When two organisms depend on each other Eg. Predator-prey relationships

Food Chain: One long string that demonstrates how organisms consume each other

Food Web: A mind map that demonstrates how organisms consume each other

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Science 9: Unit 1 - Biodiversity

Topic 1.3 - Variation within Species

Variation: The differences within a given species. Higher levels increase the chance of survival, as they can overcome disasters.

- Discrete: Refers to something that has a defined form, either/or Eg. Attached earlobes or not

- Continuous: There are a range of possible outcomes Eg. Height, shoe size

Variations in the environment aren't heritable but can change traits

Adaptations:

- Behavioural: Mental behaviours of a species Eg. Migrating birds

- Structural: Physical characteristics of a species to survive in a certain environment Eg. Giraffes grew longer necks

Natural Selection: The environment selects which species will live and which ones won't. Organisms that can adapt to new or different surroundings faster have a higher chance of surviving. Those who cannot adapt fast have a lower chance of surviving. Eg. Male giraffes battle each other with their necks to see who is the strongest. The strongest ones get to mate, which means that only the "strong" genes get passed to the next generation.

Traits: Characteristics of an organism Eg. Height, size, hair colour

- Heritable characteristics: Characteristics that are passed between generations Eg. Eye colour

- Non-heritable characteristics: Characteristics that are acquired and not passed between generations Eg. Piano skill

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Science 9: Unit 1 - Biodiversity

Topic 2.1 - Asexual and Sexual Reproduction

Asexual Reproduction: Involves only one parent, offspring are identical to that one parent.

- Budding: Smaller version of parent detaches and is clone of parent Eg. Yeast

- Binary Fission: A cell splits in two identical cells(only in one-cell organisms) Eg. Bacteria

- Spore Production: Similar to seeds but only made by one parent Eg. Mould

- Vegetative Reproduction: Doesn't involve a seed, such as cuttings, runners, grafting Eg. Potatoes, strawberries

Advantages - Only clone of parent, lots of offspring, less energy needed

Disadvantages - Exact clone(nothing new), can be wiped out easily, less variation

Sexual Reproduction: Reproduction with two individuals, offspring has a mix of genes from the parent.

In Plants -

- Gamete: Has 1/2 DNA, sperm(male) and egg(female) cell

- Fertilization: The union of the sperm and the egg(sperm penetrates egg)

- Zygote: After joining, it is the first cell of the new organism

- Cleavage: The process of dividing into many cells

- Embryo: Early development of multicellular lifeform

In Animals -

- Pollen: Contains male gametes, found in stamen

- Stamen: Has anther and filament

- Ovule: Contains female gametes, found in pistil/carpel

- Pistal/Carpel: Has stigma, style, ovary, ovule

- Pollination: Pollen is transferred from the anther to the stigma

Cross Pollination: Pollen is passed between different plants

Cross Fertilization: Pollen produces long tube to the female parts of the plant

Advantages - Lots of variations

Disadvantages - More energy and time needed, limited offspring

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Science 9: Unit 1 - Biodiversity

Topic 2.2 - Transmitter of Genetic Code

Genetics: The study of how characteristics are passed from one generation to the next

DNA (Deoxyribonucleic acid): A molecular blueprint for a living thing. Found in the nucleus. Shaped like a helix. It is made up of four molecules:

- Adenine

- Thymine

- Guanine

- Cytosine

These molecules arrange themselves in different orders like an alphabet, called the Genetic Code.

Chromosomes: Packets of information that determine the traits of an organism. Humans have 46 pairs(23 individual)

Genes: A segment of DNA that are responsible for inheritable characteristics.

Alleles: Variations of possible DNA sequences in genes (Brown: Dominant, Blue: Recessive)

Mitosis: 1 division, ends with two new cells that are identical with all chromosomes. This happens in growth and repair cells.

Steps to Mitosis:

Prophase - DNA doubles

Metaphase - Lines up in middle

Anaphase - Pulls DNA apart and splits

Telephase - Two new cells

Advantages - Fast, No partner needed, Less energy needed

Disadvantages - Identical, less variation

Meiosis: 2 divisions, ends with four cells with random amounts of half DNA. Only happens in sex cells

Steps to Meiosis:

Prophase I - DNA doubles and mixes

Metaphase I - Lines up in middle

Anaphase I - Pulls DNA apart and splits

Telephase I - Two new cells

Prophase II - DNA doubles and mixes

Metaphase II - Lines up in middle

Anaphase II - Pulls DNA apart and splits

Telephase II - Two new cells

Advantages - More variation

Disadvantages - More energy and time needed, Requi

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Science 9: Unit 1 - Biodiversity

Topic 2.3 - Patterns in Inheritance

Dominant: Trait that is always expressed, not too common

Recessive: Trait that is only expressed if other recessives are there, always overpowered by the dominant, pretty common

Purebred(homozegeous): Parents were most likely from a long line of ancestors who only have all recessive or all dominant

Hybrid(heterozegeous): Have a mix of dominant and recessive traits

Phenotype: Observable traits resulting from genes

Genotype: Consists of two letters(capital = dominant) that represent an allele

Punnet Square: Tool used to predict certain genes

Incomplete Dominance: Results in a phenotype that is a blend of allele pairs (Red + Blue = Purple)

Codominance: Results in a phenotype that shows both traits (Red + Blue = Red and Blue)

Multiple alleles have more than 2 variations

Environmental factors can also affect DNA.

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Science 9: Unit 1 - Biodiversity

Topic 3.1 - Reduction and Conservation of Biodiversity

Biodiversity is being reduced on Earth. Due to many human activities(Habitat Destruction, Introduction of Non-native Species, and Over-hunting). Some natural causes can also affect things(Volcano eruptions, floods, fires, starvation, disease, overspecialization)

Threatened: The species is soon to become endangered

Endangered: The species are at risk of going extinct

Extirpation: The disappearance of a species from a certain area

Extinction: The disappearance of a species from the entire planet

Overspecialization: An organism has too little to rely on to survive Eg. Panda (bamboo is rare)

To Reduce our Biological Footprint we have In-situ Conservation and Ex-situ Conservation:

In-situ Conservation: The conservation of biodiversity within the species' natural habitat Eg. National Parks

Ex-situ Conservation: The conservation of biodiversity outside the species' natural habitat Eg. Zoo

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Science 9: Unit 1 - Biodiversity

Topic 3.2 - Selecting Desirable Traits

Biodiversity: is the process of intervention to get desirable results

- Clone: Producing populations of genetically identical individuals

- Artificial Insemination: Artificially joining the male and female gametes

- In-Vitro Fertilization: Male and female gametes are placed in a controlled environment and forced to fertilize

- Genetic Engineering: Directly altering the DNA of an organism