Genetics and Adaptations

1. Genetics and Adaptations

2. Butterflies • Count how many butterflies you can spot on the wall • Count how many butterflies you can spot on the floor

3. 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.

4. 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?

5. 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

6. 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.

7. Homework • Write down 5 acquired traits. • Write down 5 traits that you have inherited from your parents.

8. 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?

9. How are traits passed on? • Two ways to inherit traits. Most organisms reproduce with one or the other, not both. • Asexual reproduction • Sexual reproduction • Both use genetic information (DNA) to create offspring

10. 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

11. Bacteria

12. Some Plants

13. Algae

14. Marine Life

15. hydra

16. Planeria

17. Fungi

18. 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

19. Sexual Reproduction • Advantages • More opportunity for mutations • More DNA combinations • Disadvantages • Sometimes takes longer • Some bad genes are still possible

20. Mammals

21. Birds

22. Fish

23. REptiles

24. 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 good or bad.

25. Mitosis • One cell splits into 2 cells • Makes an exact copy of itself • All the DNA, traits are exactly the same

26. 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.

27. 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.

28. 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

29. 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

30. 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!!!

31. 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

32. 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.

33. 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

34. 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

35. CoDominance and Incomplete Dominance • Co-dominance is when there is more than one dominant allele, as well as a recessive allele • Blood type: A, AB, B, O • O is recessive, A & B are dominant • Incomplete Dominance is when a heterozygous gene (one dominant and one recessive) shows a “mix” of the two • Pink flowers from a red and white allele

36. Mendel • What did he do? • Studied traits and inheritance in pea plants • Crossed purebred pea plants • Offspring, of F1 generation • Dominant and recessive alleles • Example • Round seed is dominant and wrinkled is recessive • Yellow seed is dominant and green is recessive • Tall is dominant and short is recessive

37. Punnett Squares • Method used to determine the probability of offspring having recessive or dominant traits.

38. 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

39. 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

40. Classwork/Homework • Bikini Bottom Genetics worksheet • QUIZ ON FRIDAY!!!!

41. 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.

42. 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.

43. 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.

44. 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

45. 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

46. 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

47. 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

48. Polar bears • In the wild, they live 15-18 years • In zoos, they can live 30-40 years

49. 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

50. Polar Bears • Their predators are humans, other polar bears, sometimes walruses. • Climate change is the biggest threat to bears