Genetics

1. Genetics

2. Reproduction REVIEW (not in Genetics Notes) • Genetic information is passed on through the process of reproduction. • Organisms reproduce in two ways: either sexually or asexually. • Sexual Reproduction • The offspring receive equal amounts of genetic information from two parent organisms. • The offspring show characteristics or traits from both parents but they are not exactly like either parent. • Sexual reproduction is the most common form of reproduction in multi-cellular organisms. • Advantages of Sexual Reproduction • Because genes are being mixed, the offspring of organisms can receive different forms of the same gene. Eventually (over a very long period of time), the forms of the genes that benefit a organism in terms of its ability to survive will win out over those forms of the gene that are not as beneficial to survival. This strengthens the species of organism. • Disadvantages of Sexual Reproduction • 1. It is labor intensive. Animals must find willing mates and breed. Plants must rely on wind or animals to carry the sex cell from one plant to another. It is not nearly as efficient as asexual reproduction.

3. Asexual Reproduction • The offspring receive genetic information from only one parent organism. • The offspring are genetically identical to the parent organism • Asexual reproduction is the most common form of reproduction in most cells. Some plants, small animals, and fungi can reproduce through asexual reproduction (fragmentation, budding). • Advantages of Asexual Reproduction • It is much faster and more efficient than sexual reproduction. It doesn’t rely upon outside forces to join genetic material. • Disadvantages of Asexual Reproduction • 1. Since it does not involve joining genetic material from multiple sources, it is much more difficult for organisms that undergo only asexual reproduction to adapt to changes in their environment.

4. Website links http://learn.genetics.utah.edu/content/begin/tour/ Mendel’s Experiments http://www.sumanasinc.com/webcontent/animations/content/mendel/mendel.html DNA replication http://www.johnkyrk.com/DNAreplication.html Punnett Square tutorial http://www.biology.arizona.edu/mendelian_genetics/problem_sets/monohybrid_cross/01t.html Mendel Yellow Pea Green Pea http://www.teachersdomain.org/asset/hew06_int_dominantgene/ Punnet Square animation http://www.siskiyous.edu/class/bio1/genetics/monohybrid_v2.html

5. Genetics refers to the study of inherited biological traits. At its most complex level, genetics is the study of the science of the billions of tiny building blocks that form an organism. http://www.youtube.com/watch?v=bVk0twJYL6Y Hyperlink: What makes you you?

6. Gregor Mendel is considered to be the “father” of the science of genetics. Born a poor peasant farmer in the early 1800’s, Mendel entered a monastery as a young adult. While there, Mendel experimented with growing 7 different types of peas. He noticed there were specific physical characteristics ranging from flower color to the shape of the pea that were passed on through fertilization. Mendel began to experiment with these different types of peas, crossbreeding them, etc. He was able to discover that certain physical traits were dominant, or stronger than others. From his studies, laws of heredity were born. Later, genetic scientists used fruit flies for genetic research. They were cheap and bred fast. http://www.youtube.com/watch?v=0vAAf4g5iF8

7. Mendelian Traits Genetic scientists have been able to create a huge list of dominant and recessive traits. Will learn what this means later. These traits are referred to as Mendelian Traits after Gregor Mendel. They include such things as: Free (Dominant) vs. attached earlobes. Straight thumb (D) vs. “Hitchhiker” thumb. Tongue roll (D) Let’s take a few minutes and use the Mendelian checklist to survey our fellow students for dominant and recessive traits…

9. Free earlobes-dominant

10. Cleft chin-dominant

11. Dimples- dominant

12. Freckles-dominant

13. no- hitchhiker’s thumb: dominant

14. Widow’s peak

15. Bent Pinky Finger

16. Webbed toes are usually an inherited trait. “Webbed” doesn’t mean webbed like a frog’s feet.

17. Straight Thumb Hitchhiker's Thumb Mid Digital Hair Naturally Curly Hair Naturally Straight Hair Widow's Peak Freckles Straight Pinky Finger Bent Pinky Finger Webbed Toes or Hands Cleft Chin Baldness Long Middle Toe(s) Finger Flex Thumb Crossing (right over left) Thumb Crossing (left over right) Brown Eyes Blue Eyes Hazel Eyes Green Eyes Brown Hair Black Hair Blond Hair Red Hair Dimples We are now going to survey the members of this class and create a graph using the data.

18. Show Genetics Traits Graph Example for Mendelian Traits Activity

20. Closing/Formative AssessmentWrite in your interactive notebook questions and answers. Genes • 1. ____________________ control individual traits. • 2. ____________________ is considered the father of the study of genetics. • 3. All complex organisms have ___________ of every gene. • 4. List two important discoveries about heredity made by Mendel during his experiments with garden peas. • A. Organisms have two genes for every trait, and they may be different forms of the gene. • B. Some forms of genes are stronger than others. • C. Some traits can remain hidden in one generation but appear in the next. Mendel two

21. Genetics Day TwoActivator • Genotype vs. Phenotype • Heterozygous vs. Homozygous • B-Black (Dominant) b-red (recessive) • Purebred vs. Hybrid • What is your genotype? • What is your phenotype? • Is your allele pair heterozygous or homozygous? • Are you purebred or hybrid for this trait? • (For playing card activity)

22. REVIEW DNA is the building blocks of life. DNA molecules join to form genes. Genes join to form Chromosomes. Think Don’t Go Crazy, then think of your whole genetic make-up (genome) as a book. The DNA molecules are the letters that are used to form the words. ab cdef gh i j k lmno pqrstuvw x y z The letters are put together to form words. Words are the genes, each of which controls a different trait (so is a different “word.”) Genes, like words, vary in length. Some genes are made up of more “letters” or sections of DNA. p l e a s e a tt e n ti o nc l o s ep a y t h et ot e a c h e r The words (genes) are placed together to make sentences. The sentences are the chromosomes. Like sentences, chromosomes vary in length. Some chromosomes can have hundreds of “words/genes” in them. P l e a s e p a y c l o s ea tt e n ti o nt ot h et e a c h e r. Finally, the chromosomes join together to form the complete genome---all the genetic info found inside the nuclei of each cell in your body. These chromosomes (sentences) joined together form a book. The book of YOUR life.

23. Deoxyribonucleic acid (DNA) is a nucleic acid that contains the genetic instructions or genetic code for the development and functioning of all known living organisms and some viruses. The main role of DNA molecules is the long-term storage of information. DNA is often compared to a set of blueprints, since it contains the instructions needed to construct other components of cells, such as proteins. DNA molecules are in the memorable shape of a double helix, a spiral ladder. Each rung of the spiral ladder consists of two paired chemicals calledbases. There are four types of bases. They are adenine (A), thymine (T), cytosine (C), and guanine (G). Certain bases always pair together (AT and GC). Different arrangements (known as sequences) of base pairs form coded messages. In other words, the way these bases are arranged determines which genetic trait it will effect. Hyperlink http://www.youtube.com/watch?v=qy8dk5iS1f0

24. Remember that before all cells divide, they must create an exact copy of their DNA first. DNA when it is flattened out is said to look like a ladder or a zipper. When the DNA divides in half, picture unzipping a jacket.

25. Hyperlink http://www.youtube.com/watch?v=OnuspQG0Jd0 http://www.youtube.com/watch?v=zdDkiRw1PdU Alternative Hyperlink

26. Genes join together to form chromosomes. Humans have 23 pair or 46 total chromosomes—1/2 from each parent. A chromosome is made up of thousands of genes.

27. DNA is letters. Genes are words. Chromosomes are sentences. All the sentences form a book. Don’t Go Crazy!

28. Genes –DNA molecules join together to form genes. Genes control individual traits like hair color, free earlobes, toe length, and thousands of other traits. Complex organisms have two genes for each of these traits, one from each parent. These gene pairs are known as alleles. These two alleles in the pair may be the same form of the gene (both genes for hazel eyes) or different forms of the gene (one for hazel eyes, one for blue eyes.) Different forms of the SAME gene for eye color If a person has two different forms of the same gene, what color eyes will that person have? It depends. Remember Mendel learned that some forms of genes beat out other forms of the same gene. In the case of eye color, the brown eye form of the gene always beats the blue eye form. With regards to hair color, brown always beats red. The form of the allele that is the stronger form is known as the dominant allele. The other form is the recessive allele. (Important note: Eye color is often used in genetics examples because it is easy, but these examples are not entirely accurate. Eye color is actually determined by two or three different genes. One controls color, another the amount of dark pigment.) Hazel form blue form

29. Genotype/Genome- • The term genotype refers to the combination of alleles a person has for a particular trait. A person’s genotype is represented by two letters. CAPITAL letters are always used to indicate a dominant allele. LOWER CASE letters are used to indicated a recessive allele. • For example, with Mendel’s pea plants, the color purple was dominant in the flowers. • The color white was recessive. Rather than use ‘w’ we use the same letter as the dominant but in lower case instead. P: Purple p: white Since each plant will have a pair of alleles for every trait including flower color, a plant may have any of the following allele pairs or GENOTYPES: PPPppp

30. Phenotype-the genetic traits that are visible in an organismare referred to as the organism’s phenotype. A person’s blue eyes, brown hair, long toes, and big ears are all visible signs of her phenotype. Perhaps the term “activated” is more accurate. • Not all phenotype traits are clear to see by just looking at a person. For example, a person can inherit the physical traits from a parent that lead to high blood pressure. You can’t look at a person and see that he or she has high blood pressure, but there are ways to measure it. PPPppp 3. A plant with this genotype would have what color flowers? 1. A plant with this genotype would have what color flowers? 2. A plant with this genotype would have what color flowers? Purple white Purple

31. Homozygousallele pairs have identical alleles for the same gene (the prefix homo means “same.”) For example, let’s suppose there are two different forms of the allele controlling the shape of a pea. The dominant form of the allele (Y) is the round, smooth shape. The recessive form of the allele (y) is the wrinkled shape. If the allele pairs contain identical forms of the allele (YY or yy ), they are homozygous. Y allele makes the pea round and smooth y allele makes the pea bumpy. YY seed is round, smooth yy seed is bumpy

32. Heterozygous allele pairs have different forms of the same gene (Rr) [see above] (The prefix hetero means “different.”) Y Dominant allele makes the pea round and smooth y recessive allele makes the pea bumpy. Yy gene pairs have one allele for the round smooth pea and one allele for the bumpy pea. So, for plants that have the Yy gene pair, what shape will the seed be?

33. Hybrid vs. Purebred Let’s take a look at fuzzy bunnies. In a bunch of bunnies, we have some that are white and some that are black. In the world of bunnies, black is dominant over white. Since all bunnies have two forms of the same gene, there are two ways that baby bunnies can be born black: If the capital B stands for Black and the lower case b stands for white These two bunnies look the same. But genetically they are not

34. This bunny is black. His phenotype is black. This bunny received two black fur alleles, so his genotype is BB. His allele pair is homozygous. Animals and plants that are homozygous for a particular are known as purebreds. This Fluffy bunny received one black allele from his mother but he received a white allele from his father. His phenotype is still black. His alleles are Bb, so the pair is heterozygous. Since black is dominant over white, the bunny had to turn out black. In this case, the bunny is not considered a purebred. He is considered a hybrid for black fur.

35. This fuzzy bunny is white. Is white fur a recessive trait or a dominant trait? recessive What is its phenotype? white What is its genotype? bb Is it a purebred or a hybrid for white? It would be impossible for it to be a hybrid for a recessive trait. He is a purebred white rabbit.

36. Homework Bikini Bottom Genetics Questions 1-3 You are to complete this on your own. I will not be checking them. The answers to the questions appear on p.3 of the document. Write down your answers on a sheet of paper, then check them. If you are having trouble determining the correct answer, you need to let me know during class. You WILL have a quiz that COUNTS for a grade one day this week. BE PREPARED at any moment 

37. Genetics Day Three Bell Ringer • ______________________ molecules contain the instructions or code for all living organisms. • ______________________ control individual traits. • ______________________ consist of thousands of interconnect genes. • Prior to dividing, all cells must first___________________ • ___________________________________________________. DNA Genes Chromosomes Create a copy of its DNA

38. How many different traits are you able to observe in the dragons below?

39. Guided Practice In certain species of rabbit, black fur (B) is dominant over white fur (b.) Answer the following questions related to the images of these wabbits. • My genotype is___________. • My phenotype is ___________. • My allele pair for this trait is homozygous/heterozygous (circle one.) • I am purebred/hybrid for my white color (circle one.) 5. What possible genotype(s) might I have? ________________ 6. If I have genotype Bb, what would my phenotype be? _______________ 7. If my allele pair is homozygous, what would my genotype be? ______ 8. If I am hybrid for the black fur trait, what would my genotype be? ______

40. In the human world, there are six separate genes (that we know of) that influence eye color. On the alien planet of Hodgdonia, there are only two genes that influence eye color. These questions are for the aliens of Hodgdonia Suppose Aneesahlupa’s two alleles for eye color are different forms of the gene. One is Black (B), the other red (b) . (Aneesahlupa) 4. If ‘B’ represents black and ‘b’ represents red, what will Aneesahlupa’s genotype be? Bb 5. What is Aneesalupa’s phenotype if black is dominant over red? Black since black is dominant over red. 6. Is Aneesahlupa purebred or hybrid for black eyes? hybrid

41. Rossapalooza has red eyes (his phenotype is red eyes.) Red is a recessive form of the eye color gene. 7. What MUST his genotype be? The only way he could have red eyes is if BOTH forms of his allele were bred. Red is RECESSIVE, so other forms(colors) of the eye color gene would beat it if paired with it. His genotype must be ‘bb’. 8. What form of the eye color gene will be passed on in his sex cells? Since he only has red forms of the allele, he can only pass on red.

42. 9. If the black form of the allele is dominant over the red form, which of the male sex cells will win the race to fertilize the egg? Outta my way, loser. I’M the dominator here! Whatever, dude. There is no way to tell. Dominant vs. recessive makes NO DIFFERENCE before fertilization. It only has an effect when the two forms of the gene are paired together in the zygote.

43. 10. A Hodgdonian who was heterozygous for black eyes would have what genotype? 11. What are the possible genotypes for this alien’s eye color? 12. How can we tell which of these aliens is purebred for black eyes and which is a hybrid for black eyes? b B bb You can’t…

44. 13. Aliens on a nearby planet have eyes on tops of stalks (like snails and slugs.) The form of the allele for two stalks (S) is dominant over the form of the allele for five stalks (s). What possible genotype(s) might the alien Theodorkia have? 14. This is Kellygobula. What is her eye stalk phenotype? Five Stalk 15. These two aliens (Willsicula and Sydcila) are found in the forests of Hodgdonia. In their species, purple skin (P) is dominant and red (p) is recessive. What genotype(s) might Willsicula have? 16. Based on her skin phenotype, what MUST be true about Sydcila’s parents? SS or Ss Theodorkia PP or Pp Each parent MUST have passed on a recessive p allele to Jacobleon.

45. 17. So, the only way a baby can be born with a recessive trait is: • One of the parents must have two of the recessive alleles • One of the parents must have at least one of the recessive allele to pass on. • Both parents must possess at least one of the recess allele • Both parents must have two of the recessive alleles

46. Closing/Formative Assessment Round nose (R) is dominant over pointy noses (r) in the Smoogle population. • What genotype(s) will result in a round nose? RR and Rr 2. If Snorglet is heterozygous for round nose, what is his genotype? Rr 3. Chilipophas genotype rr. What is her phenotype? Pointy nose. 4. __________ control individual traits. Genes

47. Let’s say that long toes are dominant (T) and short toes are recessive (t) 20. What possible genotypes could a person have for toes? TT, Tt, tt 21. If her genotype is… …which is (het/hom) …then her phenotype would be 22. Kyle has really long toes. What possible genotypes might he have? ___________ Homozygous long toes Heterozygous long toes also Homozygous short toes TT or Tt

48. Guided Practice (Students complete on board or on SchoolPad.) 23.

49. Guided Practice (Students complete on board or on SchoolPad.) 24. T- full tail t- bobtail P p

50. Guided Practice (Students complete on board or on SchoolPad.) B- Brown R-Round b- blue r- wrinkled 25.