GENETICS AND ADAPTATIONS

BUTTERFLIES Count how many butterflies you can

spot on the wall

Count how many butterflies you can spot on the floor

INHERITED VS. ACQUIRED TRAITS What is an acquired trait?

A trait that an organism acquires or gains over its lifetime. It cannot be passed on to its offspring. Like the ability a monkey has to peel a banana.

What is an inherited trait? A trait that is passed to offspring because of

genetic inheritance. Could be good or bad for the organism.

INHERITED TRAITS What are some examples of traits that

make an organism MORE suited to its environment?

What are some examples of traits that make an organism LESS suited to its environment?

INHERITED OR ACQUIRED? Blue eyes

Dog’s short fur

Broken arm

Blonde hair

A Cold

Sun tan

Colorblindness

Ability to roll tongue

Love of music

Ability to do math well

TOOTHPICK ACTIVITY In your group of 3, time each person for

10 seconds while they pick up toothpicks one by one.

Make a chart in your notes of how many toothpicks of each color each person picked up.Person Brown Red Yellow

Leonardo

Donatello

Michaelangelo

HOMEWORK Write down 5 acquired traits.

Write down 5 traits that you have inherited from your parents.

LAMARCK When environments changed, organisms

had to change their behavior to survive. If they began to use an organ more than they had in the past, it would increase in its lifetime. If a giraffe stretched its neck for leaves, for example, a "nervous fluid" would flow into its neck and make it longer. Its offspring would inherit the longer neck, and continued stretching would make it longer still over several generations. Meanwhile organs that organisms stopped using would shrink.

Is this true?

HOW ARE TRAITS PASSED ON? Two ways to inherit traits. Most

organisms reproduce with one or the other, not both.Asexual reproductionSexual reproduction

Both use genetic information (DNA) to create offspring

ASEXUAL REPRODUCTION The DNA of the parent is the same as

the offspring.

Any genetic mutation (whether good or bad) will be passed onto the offspring.

Mitosis

BACTERIA

SOME PLANTS

ALGAE

MARINE LIFE

HYDRA

PLANERIA

FUNGI

SEXUAL REPRODUCTION A better system for producing genetic

variation and therefore “fitness” for an environment

½ of the DNA from one parent and ½ from the other parent

Meiosis

SEXUAL REPRODUCTION Advantages

More opportunity for mutationsMore DNA combinations

DisadvantagesSometimes takes longerSome bad genes are still possible

MAMMALS

BIRDS

FISH

REPTILES

DNA Double ½ genes on one side ½ genes on other side Sex cells have ½ Mutation is a change in the DNA. Can be goodor bad.

MITOSIS One cell splits into 2 cells

Makes an exact copy of itself

All the DNA, traits are exactly the same

MEIOSIS Cell divides and makes 4 copies.

Each new cell gets ½ the DNA of the first cell.

Used in sexual reproduction to make eggs, pollen, etc.

DNA ACTIVITY Read pg C97-103 as a class.

Make an example of an offspring’s DNA in asexual and sexual reproduction.

Follow the example on the board.

LIGERS

• Lion and tiger mixed together• Half of its DNA is from lion, half

from tiger• Has traits of both animals• Does not occur in nature

OTHER HYBRIDS

Splake- hybrid of male brook trout and female lake trout

Africanized honey bee- African and European bees, “killer bees”

Beefalo-cattle and bison

Zebroid-zebra and horse

ACTIVITY

• You need to create your own hybrid!• Draw a picture of what your hybrid

would look like• List the traits it would get from each

of its parents• List the advantages and

disadvantages it would have in the wild

• DUE AT THE END OF CLASS!!!

WORDS YOU NEED TO KNOW Allele: Different forms of a gene

Homozygous: the same alleles (either both are dominant or both are recessive).

Heterozygous: different alleles

Phenotype: what an organism LOOKS like

Genotype: what an organism’s GENES say

DOMINANT ALLELES Dominant alleles occur on sections of

DNA that code for a particular trait.

If a dominant allele is present, then the organism is going to have the phenotype for that trait

Example: If you have the gene for free ear lobes, then

you will have free ear lobes.

RECESSIVE ALLELES Recessive alleles occur on DNA sections

where BOTH strands of the DNA must have the recessive allele in order for the recessive trait to be shown or expressed.

Example: If you have 1 gene for connected ear lobes,

and 1 gene for free ear lobes, then you will have free ear lobes

If you have 2 genes for connected ear lobes, then you will have connected ear lobes

HOW TO REPRESENT GENES In “genetic writing”, dominant

traits/alleles are represented by capital letters, such as “B”

Recessive traits/alleles are represented by lower case letters, such as “b”

BB=homozygous dominant bb=homozygous recessive Bb=heterozygous

CODOMINANCE AND INCOMPLETE DOMINANCE Co-dominance is when there is more

than one dominant allele, as well as a recessive alleleBlood type: A, AB, B, OO is recessive, A & B are dominant

Incomplete Dominance is when a heterozygous gene (one dominant and one recessive) shows a “mix” of the twoPink flowers from a red and white allele

MENDEL What did he do?

Studied traits and inheritance in pea plantsCrossed purebred pea plantsOffspring, of F1 generationDominant and recessive alleles

ExampleRound seed is dominant and wrinkled is

recessiveYellow seed is dominant and green is

recessiveTall is dominant and short is recessive

PUNNETT SQUARES Method used to determine the

probability of offspring having recessive or dominant traits.

PRACTICE In humans, brown eyes (B) are dominant

over blue (b)

Blue eyed mom and homozygous brown eyed dad

Blue eyed mom and heterozygous dad

Heterozygous mom and dad

PRACTICE In dogs, there is an hereditary deafness

caused by a recessive gene, “d.”

What percentage of dogs would be deaf if…

Homozygous dominant and heterozygote

Heterozygote and homozygous recessive

Homozygous dominant and homozygous reccessive

2 heterozygotes

CLASSWORK/HOMEWORK Bikini Bottom Genetics worksheet

QUIZ ON FRIDAY!!!!

SQUIRRELS OF THE GRAND CANYON:  Originally, there was only one species of

squirrel living in the Grand Canyon. As the Grand Canyon deepened and widened, the group of squirrels on the north side of the canyon got separated from the group on the south side. The squirrels separated on the north side now have black fur, while the squirrels on the south side have red fur. The separation of the two groups caused them to evolve different traits. The two groups are becoming more and more genetically different, and in time will likely become two different species.

CORN AND COWS: People have been selectively breeding

plants and animals for a long time.  Native Americans produced corn by selectively breeding a species of weed.  The corn they produced had ears that were only three inches long.  Modern science has increased the length of the ears to one foot long.  Farmers cross cows that produce the most milk to produce new generations of cows that produce increasing amounts of milk.

FINCHES As Charles Darwin conducted research

on the Galapagos Islands, he noticed differences in finches from island to island.  One of the biggest differences was the sizes and shapes of the bird beaks.  Each bird had the type of beak it needed to survive.  Finches that ate insects had sharp needlelike beaks.  Those that ate seeds had strong, wide beaks.  The shape of the beak is an example of an adaptation, or change over time, that helped the birds survive.

POLAR BEARS Polar bears live in the Arctic areas. They

DO NOT live in the southern hemisphere

Adult males are 8-10 feet tall and weigh 550-1700 pounds

Adult females are 6-8 feet tall and weigh 200-700 pounds

POLAR BEARS Have 2 layers of fur. Their fur is clear

and hollow. It is oily and repels water.

They have a layer of blubber (fat) to insulate them. It can be up to 4.5 inches thick

Compact ears and small tail prevent heat loss

Bumps on feet keep them from slipping on the ice

POLAR BEARS Slightly webbed paws to help them

swim

Powerful claws to catch seals

Nose can detect prey from miles away

They can dig out shelters and curl up in them to get out of the cold, wind

POLAR BEARS Eat walruses, seals, small whales,

reindeer, birds, bird eggs, seaweed, small mammals, plants, berries

They try to kill a seal about every 5-6 days

POLAR BEARS In the wild, they live 15-18 years

In zoos, they can live 30-40 years

POLAR BEARS They do not hibernate

Mothers make dens when they give birth and the babies stay in it for about 4 months

Mothers usually have 2 cubs at a time

Baby polar bears are the size of a rat when they are born

POLAR BEARS Their predators are humans, other polar

bears, sometimes walruses.

Climate change is the biggest threat to bears

POLAR BEARS There are 25,000-40,000 polar bears in

the world.

In winter, polar bears sleep in shallow pits they dig in the snow with their sides or backs to the wind.

Polar bears need to have ice to hunt seals.