Passing it OnPassing it On

Topic 3: BiodiversityTopic 3: Biodiversity

After this Topic, I need to After this Topic, I need to be able to:be able to:

DescribeDescribe the types of asexual the types of asexual reproductionreproduction

DistinguishDistinguish between sexual and asexual between sexual and asexual reproductionreproduction

Provide examplesProvide examples of organisms that of organisms that show each type of reproductionshow each type of reproduction

DescribeDescribe zygote and embryo formation in zygote and embryo formation in plants and in animalsplants and in animals

…… Think about your parents… do you look like them?Think about your parents… do you look like them? How does reproduction allow for variation?How does reproduction allow for variation?

Not only do the physical traits of organisms vary, Not only do the physical traits of organisms vary, but but thethe ways in which organisms reproduce ways in which organisms reproduce show variation as well. show variation as well.

Heritable:Heritable: Traits that are passed on from parent to Traits that are passed on from parent to

offspring.offspring. Passed on in genetic materialPassed on in genetic material

Reproductive Strategies:Reproductive Strategies: Binary fissionBinary fission SporesSpores Vegetative growth in plantsVegetative growth in plants BuddingBudding Sexual reproductionSexual reproduction

http://www.youtube.com/watch?http://www.youtube.com/watch?v=jk2RJm5RBEkv=jk2RJm5RBEk

Asexual Reproduction

Asexual ReproductionAsexual Reproduction

Occurs when only one parent supplies Occurs when only one parent supplies the information to the offspring.the information to the offspring.

The genetic material of the offspring, and The genetic material of the offspring, and thus their inherited characteristics, are thus their inherited characteristics, are identical to those of the parent.identical to those of the parent.

Common among:Common among: BacteriaBacteria FungiFungi

Advantages:Advantages:

No need for an organism to find a mateNo need for an organism to find a mate

Reproduction occurs quite rapidlyReproduction occurs quite rapidly

Offspring will be able to survive and Offspring will be able to survive and reproduce as their parents did, as long as reproduce as their parents did, as long as the environment does not change too the environment does not change too muchmuch

How would the use of wind-borne seeds How would the use of wind-borne seeds increase variation in plant species?increase variation in plant species?

Figure 1.20Figure 1.20

Write a different type of asexual reproduction Write a different type of asexual reproduction in each square.in each square. Binary fissionBinary fission Asexual sporesAsexual spores Vegetative reproduction – asexual reproduction Vegetative reproduction – asexual reproduction

in plantsin plants BuddingBudding

In each square:In each square: Include 2 pieces of important information about Include 2 pieces of important information about

the type of asexual reproductionthe type of asexual reproduction Include 1 example Include 1 example

Binary Fission, Spores, Binary Fission, Spores, Vegetative Reproduction, Vegetative Reproduction, BuddingBudding

In each square:In each square: Include 2 pieces of important Include 2 pieces of important

information about the type of information about the type of asexual reproductionasexual reproduction

Include 1 example Include 1 example

Binary Fission (AS)Binary Fission (AS) Cell divisionCell division

Steps:Steps: The cell duplicates its contents, including The cell duplicates its contents, including

it’s nucleus and other organellesit’s nucleus and other organelles DivisionDivision Each new cell has a copy of genetic Each new cell has a copy of genetic

material and half of a cytoplasmmaterial and half of a cytoplasm Offspring are identical!Offspring are identical!

What are the new cells referred to as?What are the new cells referred to as? ““daughter cells”daughter cells”

Asexual SporesAsexual Spores

Common in fungi (mushrooms) Common in fungi (mushrooms) Spores:Spores:

A single-celled reproductive structure from which an A single-celled reproductive structure from which an individual offspring develops plants, algae and fungiindividual offspring develops plants, algae and fungi

Only one parent organism supplies the genetic Only one parent organism supplies the genetic material material

Produced to ensure that at least some of them Produced to ensure that at least some of them survive survive

Common examples:Common examples: FungiFungi AlgaeAlgae

ChlamydomonasChlamydomonas UlvaUlva

Why do you think zoospores have flagella? Why do you think zoospores have flagella?

Produce zoospores:

- Move using tail-like flagella.

Asexual Reproduction in Asexual Reproduction in Plants (Vegetative Plants (Vegetative Growth)Growth)

Plants continue to grow throughout their Plants continue to grow throughout their liveslives

MeristemMeristem:: Growing tips on roots and stems that contain Growing tips on roots and stems that contain

rapidly reproducing cellsrapidly reproducing cells

Meristematic cells are able to make Meristematic cells are able to make repairs to damaged roots, leaves, or the repairs to damaged roots, leaves, or the stem of the plant.stem of the plant.

You can try this at home!You can try this at home! Cuttings from a parent stem may be used to Cuttings from a parent stem may be used to

produce new plantsproduce new plants that are that are clonesclones (exact copies) of their(exact copies) of their parents. parents.

BuddingBudding

What is budding? (find the definition and What is budding? (find the definition and write it down!)write it down!)

A bud forms on an organism, grows, and A bud forms on an organism, grows, and eventually breaks away to become a new eventually breaks away to become a new organism independent of the parent. organism independent of the parent.

Common among:Common among: Sea spongesSea sponges hydrahydra

Sponge buds may remain attached to the parent which Sponge buds may remain attached to the parent which results in a colony. What advantage does the bud have results in a colony. What advantage does the bud have by being attached to its parent?by being attached to its parent?

Hydras are very small organisms that live in Hydras are very small organisms that live in water. Based on what you have learned about water. Based on what you have learned about budding, describe what is happening in this budding, describe what is happening in this picture. picture.

Sexual ReproductionSexual Reproduction Occurs when 2 parents supply genetic Occurs when 2 parents supply genetic

material to the offspring material to the offspring

Offspring will Offspring will NOT be exactly the same NOT be exactly the same have a combination of both parents characteristics have a combination of both parents characteristics allows for allows for VARIATIONVARIATION!!

Takes a lot of energy – few offspringTakes a lot of energy – few offspring

The Best of Both WorldsThe Best of Both Worlds

Many organisms are capable of both Many organisms are capable of both asexual and sexual reproductionasexual and sexual reproduction

Ex: Rhizopus (mould)Ex: Rhizopus (mould) Produce spores with both parents genetic Produce spores with both parents genetic

informationinformation

Types of Sexual Types of Sexual ReproductionReproduction

Notes on:Notes on: bacterial conjugationbacterial conjugation animal reproduction,animal reproduction,

and and flowering plant reproductionflowering plant reproduction

http://www.sciencedaily.com/videos/http://www.sciencedaily.com/videos/6ede1a6561dcae63b529a554ba5f704c.h6ede1a6561dcae63b529a554ba5f704c.htmtm

Topic 4: Wearing Your Topic 4: Wearing Your GenesGenes

Read pg. 37 paragraph #1Read pg. 37 paragraph #1

Genetics: Genetics: the study of genes or heritable the study of genes or heritable traitstraits

Study this family Study this family portrait and look for portrait and look for the child’s traits that the child’s traits that are:are:

the same as both the same as both parentsparents

the same as one the same as one parentparent

intermediate intermediate characteristics (in characteristics (in between the traits of between the traits of both parents)both parents)

different from both different from both parentsparents

Variation is only a benefit if it passed on Variation is only a benefit if it passed on to the next generation.to the next generation.

HeritabilityHeritability:: info can be passed on from info can be passed on from generation to generationgeneration to generation Colour of eyesColour of eyes

Non-heritableNon-heritable: gain something from your : gain something from your environmentenvironment Ex: musclesEx: muscles

2 Kinds of Variations2 Kinds of Variations

1.1. Continuous variation Continuous variation : refers to a : refers to a rangerange of different forms of a characteristicsof different forms of a characteristics

Have a defined formHave a defined form Ex: range of hair colourEx: range of hair colour

2.2. Discrete variationDiscrete variation: : either/oreither/or form of a form of a characteristiccharacteristic

Not a set number or anotherNot a set number or another Ex: light Ex: light dark hair colour dark hair colour

Bring your hands Bring your hands together and interlock together and interlock your fingers.your fingers. Which thumb is on top?Which thumb is on top?

Now, do opposite.... Is it Now, do opposite.... Is it uncomfortable?uncomfortable?

The way you put your The way you put your hands together is a hands together is a genetic trait!genetic trait!

To do:To do:

Pg. 38 “Observing Human Pg. 38 “Observing Human Characteristics”Characteristics” Make a bar graphMake a bar graph #1-3 questions#1-3 questions

Allele:Allele: Is one of two or more forms of the DNA Is one of two or more forms of the DNA

sequence in a particular gene sequence in a particular gene

InheritanceInheritance

Every animal has 2 alleles for every traitEvery animal has 2 alleles for every trait 1 from the mother, 1 from the father1 from the mother, 1 from the father

TraitTrait: a characteristic of an organism: a characteristic of an organism

Capital letter – dominant allele (Ex. B)Capital letter – dominant allele (Ex. B) Lower case letter – recessive allele (Ex. b)Lower case letter – recessive allele (Ex. b)

BB or bb– BB or bb– purebredpurebred animals animals Bb – Bb – hybridhybrid (also called carriers) (also called carriers)

How can we figure out what How can we figure out what allele is dominant?allele is dominant?

By crossing 2 different purebred animalsBy crossing 2 different purebred animals Ex: You have a white female cat and a

black male cat and all the kittens are black. Which color is dominant? Are these kittens still hybrids? Would the same the same results happen each time? Would a Bb & BB look the same?

The hidden traits (the b in Bb) are called The hidden traits (the b in Bb) are called recessive recessive while the ones that we can see (B while the ones that we can see (B in Bb) are called in Bb) are called dominantdominant

Ex #2: Two hybrid cats mate. 3 kittens are black, 1 is white. Why?

Other Patterns of Other Patterns of InheritanceInheritance

Incomplete DominanceIncomplete Dominance

Note: the dominant/recessive pattern of Note: the dominant/recessive pattern of inheritance does not always occur!inheritance does not always occur!

Ex: white purebred snapdragon is Ex: white purebred snapdragon is crossed with a red purebred snapdragon crossed with a red purebred snapdragon = What is the outcome?= What is the outcome?

PINK snapdragons!PINK snapdragons! Therefore both the white and red traits Therefore both the white and red traits

are dominant OR recessive!are dominant OR recessive!

An Assumption...An Assumption...

Many people connect the Many people connect the frequency of a frequency of a characteristic with whether characteristic with whether it is dominant or recessive. it is dominant or recessive. People often assume that if People often assume that if a trait is widespread a trait is widespread (frequency) in a population, (frequency) in a population, then it must be dominant.then it must be dominant.

However dominance and However dominance and frequency are different. frequency are different. The frequency of a trait The frequency of a trait can vary from population to can vary from population to population.population.

Changing Our Genetic Changing Our Genetic InformationInformation

Genetic information can be changed by Genetic information can be changed by factors in the environment and by random factors in the environment and by random errorserrors

These changes to DNA are called These changes to DNA are called mutationsmutations

MutagensMutagens: cause mutations: cause mutations Ex: x-rays, UV rays, cosmic rays, chemicalsEx: x-rays, UV rays, cosmic rays, chemicals

Mutations can have little or a lot of effect on Mutations can have little or a lot of effect on an organism.an organism.

Can be beneficial or harmful!!!Can be beneficial or harmful!!!

Mutations can:Mutations can: Cause cancer (uncontrolled dividing of cells)Cause cancer (uncontrolled dividing of cells) Be passed on from parent to offspringBe passed on from parent to offspring

Are mutations always negative? Provide Are mutations always negative? Provide one examples of a positive mutation, and one examples of a positive mutation, and describe how it is beneficial. describe how it is beneficial.