Biological Diversity

Grade 9

What happens if there is a dominant allele?

It will always be expressed

Gene

A section of DNA that codes for a trait

Allele

A different version or expression of the same gene (can be dominant or recessive)

Genotype

An organisms’s combination of alleles (heterozygous vs homozygous)

Phenotype

The physical expression of a certain gene (e.g. brown eyes)

Homozygous dominant

An organism’s gene contains 2 dominant alleles

Heterozygous

One allele is dominant and the other is recessive (the recessive allele is not expressed)

Homozygous recessive

The organism’s gene contains 2 recessive alleles

What is the percentile chance of the offspring having brown eyes

100% chance

What is the percentile chance of the offspring having brown eyes

50% brown eyes, 50% blue eyes

Sexual Reproduction

A result of 2 parents donating 50% of their DNA to form a zygote whcih will become the offspring

What is the advantage of sexual reproduction

It gives a high degree of genetic variation

What are the steps in sexual reproduction

1. Fertilization

2. Mitosis

3. Mitosis and differentiation

Sex cells

Egg and sperm cell

n+n= 2n (50+50= 100%)

Zygote

Contains 2n (100%) of it’s own DNA

Fertilization

Process where 1 sperm cell and 1 egg cell combine

Mitosis

Process where cells divide and make copies

Blastocyst

A big ball or clump of cells

Mitosis and differentiation

The process where cells change and specialize

Mitosis

The replication/division process of all body cells

1 division

2 daughter cells

Explain each step in Mitosis

Meiosis

The process of forming gametes in reproductive organs

2 divisions

4 daughter cells

Explain each step in meiosis

What are some sexual reproduction strategies

• Bacterial conjugation

• Zygospores

• Angiosperms

• Gymnosperms

• External fertilization

• Internal fertilization

Disadvantages of sexual reproduction

• Can be difficult to find a mate

• Usually requires 2 bodies

• Requires more time and energy

• Physical limitations

What sexual reproduction strategy is this?

Bacterial conjugation

Bacterial conjugation

• Does not produce offspring

• Does increase genetic variation by exchanging DNA

Zygospores

• Use by mushroom, mold, etc.

• Hyphae from different colonies meet up and donate DNA to form offspring with increased variation

Angiosperms

Sexual reproduction of flowering plants

Gymnosperms

Sexual reproduction of coniferous trees using cones

External fertilization

Gametes from two parents are released into the surrounding environment, usually with fish eggs and needs MANY gametes

Internal fertilization

Fertilization occurs inside of the body of the parent with an egg cell, this has a high chance of fertilization and only one egg cell is necessary

Asexual reproduction

One parent makes a copy of themselves, the offspring and parent are genetically identical (AKA cloning)

Binary fission

• Primarily used by bacteria cells

• Cell doubles its genetic information (DNA), and then splits into 2 genetically identical cells

This process is similar to mitosis

Spores

• A single cell is formed by 1 parent to produce offspring

  • Spread by wind, animals and sometimes water

• Very hardy, and can survive many extreme conditions

• Used by mushrooms, mold, fungi and some ancient plants (e.g. ferns)

Budding

• Genetic info is copied but in a smaller version (some info is lost)

  • A smaller daughter cell is formed

• Used by yeasts, mods and some aquatic unicellular organisms

Vegetative reproduction

• Propagation

  • A basic stem cutting

  • The new roots develop in soil or water

  • New plant growth is in cells called meristem cells

Types of asexual reproduction

• Vegetative reproductions

• Binary fission

• Spores

• Budding

Advantages of asexual reproduction

• Fast- makes offspring quicker and repopulation is faster

• Alone- Don’t need a partner

• Possibly higher success- If the parent was successful due to genetics the offspring should be too

Disadvantages of asexual reproduction

• LESS genetic variation

  • More vulnerable to environmental changes

  • Less chance of survival

Natural selection

A process which selective pressures from the environment determine which traits/adaptations are passed down to offspring (happens over many years)

Rules for a species to survive

• All organisms will produce more offspring than the rate of mortality

• Variation will exist within a population

• Some variations will increase an organism’s chance of survival in a specific environment

• Organisms that survive will reproduce and pass down traits

Overtime the population “should” have higher advantageous traits

Explain this process

The white version in this baseline is more visible to predators in this environment, then fewer white organisms survive and proportionally reproduce, each generation we see a higher proportion of pink

Types of selective breeding

• Grafting

• Cross pollination

• Seed selection

• Cross-breeding

• Selective breeding

• Out crossing

Grafting

Take one part of one plant and attach it to another (e.g. an apple tree with 3 varieties)

Cross pollination

We take pollen from a “desirable” plant and use it to fertilize another “desirable” plant

Seed selection

We only replant seeds from “desirable” plants

Cross-breeding

We facilitate the reproduction between 2 breeds with “desirable” traits → Hybrids (e.g. Labradoodles)

Selective breeding

We only allow individuals with certain traits to reproduce (e.g. Golden retriever)

Out crossing

Trading and breeding animals between 2 zoos to increase variation within captivity

Genetic engineering

We provide specific changes to DNA

Bacterial over production

Making bacteria produce LOTS of a specific protein by injecting it with DNA

Pros and cons of bacterial overproduction

Pros- easy, quick and ethical

Cons- Public fear, limited application

Label the diagram

Transgenic animals

Isolating a gene from one animal and inserting it in another using CRISPR+ Cas9 (e.g. cows producing silk)

Pros and Cons of transgenic animals

Pros- Many applications, no death required

Cons- Complex, ethical concerns

Adaptation

An inherited characteristic that helps an organism survive

How many kinds of adaptation are there?

2

What are the kinds of adaptation?

Structural and behavioural

Variations

Differences in characteristics caused by genetic and environmental factors

What does generational trauma effect?

Variations (behaviour)

Biological diversity

Describes the variety of life forms on Earth

Species

A group of organisms that have the same structure and can reproduce with one another (e.g. humans can only reproduce with other humans)

How does the loss of one species affect another?

When a key species (e.g. coral) dies out it can causes the collapse of the ecosystem as a whole, but in most cases the ecosystem has enough biodiversity to not collapse (still affected though). *Depends on the biodiversity in the ecosystem

Population

When members of a species live in a specific area and share the same resources (e.g. all the magpies living in one park)

Community

When populations of different species live in the same area (the park has other bird species than the magpie)

What is the difference between an ecosystem and a community?

A community is all the different populations and an ecosystem is the communities combined

Speciation

The evolution of different species from one common ancestor (e.g. lynx, bobcat and cougar all came from the same commmon ancestor)

Structural adaptation

An inherited physical characteristic that helps an organism survive in it’s environment (e.g. pitcher plant’s shaped leaves helps them catch insects)

Behavioural adaptation

An inherited behavioural characteristic that helps an organism survive in it’s environment (e.g. owls hunting at night, bird migration, etc.)

Diversity index

The measure of diversity in an area, it compares the diversity of species in the area with the total number of species in the same area.

Diversity

The number and variety of species in an ecosystem

Survival

The ability to grow, live and reproduce despite environmental challenges

Higher genetic diversity (variation)=

Higher survival

What happens to diversity when nearing the poles vs. diversity around the equator?

Diversity decreases as you near the poles and there is an increase in competition for resources near the equator

The areas closer to the poles have…

More variable temperature and humidity, and food and shelter are more scarce

The areas near the equator has…

The region of highest biodiversity. The climate, temperature, and humidity is stable and sources of food and shelter are more plentiful

Niche

Where an organism lives and it’s overal role/place

Specialists

• Have a specific/narrow niche

• Have specific needs

• Don’t adapt easily

• High number of specialist species, less populations around the world

Generalists

• Have a broad/general niche

• Easily adapt because they can thrive in several niches

• Smaller number of generalist species, more populations around the world

Competition

the interaction between organisms trying to get an advantage with regards to resources

What kinds of resources do organisms compete for?

Food, water. shelter, territory, mates, sunlight, nutrients, etc.

Symbiotic relationship

Some organisms have evolved to live in close contact with each other, even though they are different species

Parasitism

A relationship in which one organism benefits and the other is negatively impacted

Examples of parasitism

Tape worm and human, leech and other organisms, cuckoos and other birds

Misconceptions with parasitism

Lice affects humans and dogs but not birds

Commensalism

A relationship in which one organism benefits and the other is not impacted

Examples of commensalism

Whale and barnacle, tree frogs and plants, cattle egrets and buffalo

Misconceptions with commensalism

Barnacles do not affect whales but they do harms organisms like turtles

Mutualism

A relationship in which both organisms benefit

Mutualism examples

Three sisters, bee and flower, clown fish and anemones

Misconceptions with mutualism

Cleaner fish and client

Genetic variation

Variations in heritable traits among members of the same species (e.g. height, eye colour, skin colour, etc.)

Diversity

Differences between different species, number and variety (e.g. 5 oak vs 3 spruce)

When we talk about the expression of genes to provide certain traits, how many types are there?

There are 2 types

Discrete

Variations that exist within a distinct number of separate categories (e.g. Rollins Rs, curling tongue or isothiocenate receptors)

Continuous

Variations that exist as a range of possibilities with room for nuance (e.g. hair colour, height, skin colour, etc.)

What is essential to a species survival?

Genetic variation, which is made possible due to changes in DNA