LOE
What is a species?
What is monoculture?
Species: organisms that can reproduce with one another and produce fertile offspring
A farm with only one plant growing.
Why do Cells Divide?
● Because they cannot grow any larger
● To repair or replace damaged cells
● For reproduction and growth
There are two types of cell division:
● Mitosis ● Meiosis
What is Competition? Example.
Competition occurs when species compete for resources, mates, or territory. Organisms may compete for food, water, sunlight, shelter, territory and mates
Important:
Competition does not always involve physical fighting.
There are two types of competition....
interspecific competition - competition between different species
Examples:
- Coyotes and foxes hunting similar prey
- Grass and dandelions using water from the same soil
intraspecific competition - competition among members of the same species Examples:
Examples:
- Elks competing for the
same mate
- Two bears fishing in the
same area
-
Variation of Characteristics
Continous vs. Discrete
Variation of Characteristics
Discrete Variation
● You either have the characteristic or you don't.
● Individuals fall into a number of distinct classes or categories
● Example: Blood groups, hand clasping, Widows Peak
Continuous Variation
● There is a range (variety) of possibilities
● Is the combined effect of many genes
● Significantly affected by environmental influences.
● Example: Milk yield in cows, length of human hands,
height, weight
Natural Selection, Artificial Selection, Evolution
Evolution
Over time, changes can lead to drastically different species, even if they have a common ancestor!
Can happen naturally (natural selection) or influenced by humans (artificial selection)
Natural Selection is the driver of evolution.
● The environment “selects” which individuals
will survive, reproduce and pass on their “favoured/selected” traits.
Theory of Natural Selection
1. All organisms produce more offspring than can possibly survive
2. There is incredible variation within each species
3. Some of these variations increase the chances of an organism
surviving to reproduce (survival of the “fittest”)
4. Over time, variations that are passed on lead to changes in the
genetic characteristics of a species
What is Biodiversity ?
Biodiversity: The variety of species and ecosystems on Earth and the ecological processes of which they are a part
Meiosis.
Meiosis
Meiosis is the process of cell division where genetic material is copied, divided, then divided again (50% of the chromosomes as the parent cell)!
50% 50% 50% 50% DNA DNA DNA DNA
When does Meiosis Occur?
● For production of gametes (reproductive cells)
● Each new cell only has HALF of the genetic information (half
the number of chromosomes) as the original
● Organisms that reproduce sexually, produce gametes through this process.
Symbiotic Relationships
A symbiotic relationship between living things happens when different species live in direct contact with one another.
Commensalism is where one organism benefits and the other is neutral
- Mutualism is where both organisms benefit
- Parasitism is where one organism benefits and the
other is harmed
Behavioural adaptation vs. Structural adaptation.
Structural Adaptation
Structural Adaptation:
● Physical characteristic (appearance/body structures) that helps an organism survive in its environment
● It can be passed on from generation to generation.
Behavioural Adaptation
Behavioural adaptation
● Behavioural characteristic (what an organism does or how it acts) that helps an organism survive in its environment
● It can be passed on from generation to generation.
Asexual Reproduction. Sexual Reproduction.
Asexual Reproduction
● Asexual Reproduction - formation of a new individual from a single organism
● Offspring are identical to the parent (clones).
● Inherited traits are like the parents (i.e SAME DNA)
● Ex. bacteria, fungi, and sea stars!
Asexual Reproduction - Advantages
● No energy wasted in finding a mate
● Does not require a specialized cell or
way of getting the gametes together
● Can occur rapidly (bacteria - 20
minutes!)
● Large numbers of offspring
● Can occur in various environments
Asexual Reproduction - Disadvantages
● Negative mutations linger longer
● Diversity is limited
● Inability to adapt
● Overcrowding
● Reproduction can create competition and species cannot adapt to survive
Sexual Reproduction - Involving two sexes/mating types and results in offspring with in a combination of genes
● Both parents supply genetic characteristics so the offspring will display a combination of both of the parents
Sexual Reproduction - Advantages
● Creates genetic diversity
● More diversity = more resistant to change
● Evolutionary advances due to variation
Sexual Reproduction - Disadvantages
● Takes time & more energy
● Must provide a way for gametes (sperm and egg) to meet
● Limited number of offspring
● Not 100% certain/effective
● Favourable genetics might not get passed on
What is abiotic? What is biotic? What do all living things have?
Abiotic factors : are the parts of an ecosystem that are not living(water, rocks, sunlight etc.)
Biotic factors : are the parts of an ecosystem which are living (or were living at one time) All living things:
- Made of cells
- Can grow
- Require energy (food to survive but how they get or make food differs)
- Reproduce
- Respond to changes in their environment
- Can adapt/evolve with their environment
What is a niche?
Niche is the role or job an organism has in an ecosystem. One organism may fill several niches.
A niche includes where it lives, goes and it’s impact on other organisms in the ecosystem.
What is a community?
What is a population?
Community: A collection of different species that live in the same ecosystem.
Population: All of the individuals from one specie that live in the same ecosystem.
Heritable vs Non-heritable.
Heritable traits- are passed on from parent to offspring
through genes
Non-heritable- traits that are acquired, not passed down
Examples of heritable traits?
- fur/hair colour
- Facial features (nose, eyes,
ears)
- Eye colour
- Skin colour
- Height
- Weight
Examples of non-heritable traits?
- Scars
- Personality
- Athletic skills - Apparel
- Dyed hair
Binary Fission - Asexual Reproduction
Binary Fission
● Binary Fission - when a parent cell duplicates its genetic information (DNA) and splits itself in two exact copies (daughter cells).
● The parent cell undergoes mitosis
Only single celled organisms, such as bacteria, and some protists (amoebas and algae), reproduce by binary fission
What is Ecosystem Diversity?
What is Species Diversity?
What is Genetics Diversity?
1. The variety of different habitats, communities, and non-living factors (like climate and water) in a region or across the planet.
2.The number of different species (and how evenly they are distributed) in a specific place.
3. The variety of genes and DNA inside a single species or population.
What is a Generalist? Example.
What is a Specialist? Example.
Generalists have adaptations that allow them to
survive in a variety of environments and eat a variety of foods - they fulfill a broad niche.
Example: Raccoons
- Omnivores (eat fruits, nuts, insects, small animals, bird eggs and human garbage
- They den in tree cavities, rock crevices, abandoned burrows, chimneys, and human-made structures
Specialists have very specific adaptations that make them very
efficient at surviving in that one type of stable environment - they fulfill
a narrow niche.
Example: Giant Pandas
Specialist
- Bamboo makes up 99% of their diet. They must eat huge amounts of it every day to survive.
- They live only in high-altitude temperate forests in the mountains of central China where bamboo grows.
- They evolved a special enlarged wrist bone that acts like a thumb to grip bamboo stalks.
What is variation?
Variation
Variation refers to physical or behavioural differences in organisms caused by genetics or environmental factors.
Genetic Variation: caused by differences in DNA. Environmental Variation: caused by differences in
surroundings and lifestyle.
Genetic + Enviro: some variation is linked to genes but also dependent on lifestyle!
DNA, chromosomes, alleles, genes
DNA (deoxyribonucleic acid)- the carrier of genetic information.
It is like a blueprint to what makes each organisms unique.
Allele - Different forms of a gene that are caused by mutation and are found at the same place on a chromosome.
You have the gene for eye color – the allele OF that gene causes you to have various eye colors (brown, blue, green)
All living things on earth have DNA
DNA is all made out of the same molecules, called nucleotides
There are 4 types of nucleotides A,C,G,T
The different patterns of these 4 molecules, cause each organism to have unique DNA
If you took all of your DNA and stretched it out, it would loop around the solar system twice..... DNA is very long.
Chromosomes- structures that contain DNA. Keeps it organized
Genes- a section of DNA that expresses a characteristic.
Spore Reproduction - Asexual
Spores- are when certain organisms produce small circular bodies that are genetically identical to the parent organism.
These small circular bodies (spores), when released, can create a new copy of the parent organism.
Many fungi, green algae, some moulds, and non-flowering plants (ie. Ferns) reproduce by producing spores.
● Spores are usually
spread/carried by the wind, water, animals, etc.
● Very hardy, can survive harsh conditions
Internal vs External Fertilization
Internal Fertilization
● Insects, reptiles, birds, mammals and some fish and amphibians
● Sperm meets the egg inside of the body
● Reduces harsh climates and predators
● Smaller number of sperm and eggs are needed
External Fertilization
● Worms, fish, amphibians
● Sperm meets the egg outside
of the body
● Moisture is needed for the sperm to swim
● Lots of energy is spent to produce large numbers of eggs and sperm
Mitosis.
Mitosis
Mitosis is the process of cell division where the genetic material is copied then divided so that the new cells have identical information to the original cell (same number of chromosomes as the parent cell).
100% DNA
100% DNA
When does Mitosis Occur?
● For the reproduction of somatic cells (body cells, NOT reproductive cells)
● For growth, repair, and replacement of tissues
● Process by which ASEXUAL reproduction occurs
What is Speciation?
Over time, living things can evolve into similar yet separate species, due to environmental changes or struggles - this is called speciation.
● Much of Earth's biological diversity is due to speciation.
Evolutionary process by which new species are created.
Alleles
Heterozygous
Homozygous
There are two types of alleles: dominant and recessive
- A DOMINANT allele will “hide” the recessive allele.
Both parents do not need to
have the allele.
- A RECESSIVE allele will only
show if both parents have the allele.
————— Heterozygous = different alleles.
————— Homozygous = same alleles
Vegetative Reproduction - Asexual
Vegetative Reproduction
● A new plant can grow from a part of the parent
● If you take a cutting from certain plants and place it in water, the cutting will grow roots, eventually developing a new identical plant.
Ex: Ex:
Strawberry plants have runners that put down roots
Roots develop in water from cuttings