Unit 4 Genetics Section 3 Genetics Access Biology
Unit 4 Genetics Section 3 Genetics Access Biology
Vocabulary with videos What is DNA? Genetics Biotechnology Sections for the Genetics Unit
SC. 912. L. 16. 1 Use Mendel's laws of segregation and independent assortment to analyze patterns of inheritance. Standards for Genetics • SC. 912. L. 16. In. 1 Identify that genes are sets of instructions that determine which characteristics are passed from parent to offspring. • SC. 912. L. 16. Su. 1 Recognize characteristics (traits) that offspring inherit from parents. • SC. 912. L. 16. Pa. 1 Recognize similar characteristics (traits) between a child and parents, such as hair, eye, and skin color, or height. SC. 912. L. 16. 8 Explain the relationship between mutation, cell cycle, and uncontrolled cell growth potentially resulting in cancer. • SC. 912. L. 16. In. 4 Identify that cancer can result when cells change or grow uncontrollably. • SC. 912. L. 16. Su. 3 Recognize that cancer may result when cells change or grow too fast. • SC. 912. L. 16. Pa. 3 Recognize that illness can result when parts of our bodies are not working properly. SC. 912. L. 14. 6 Explain the significance of genetic factors, environmental factors, and pathogenic agents to health from the perspectives of both individual and public health • SC. 912. L. 14. In. 4 Describe common human health issues. • SC. 912. L. 14. Su. 3 Recognize common human health issues. • SC. 912. L. 14. Pa. 3 Identify ways to prevent infection from bacteria and viruses, such as hand washing and first aid.
What is Genetics and who is Mendel? Essential Questions/Big Ideas for Genetics What is a Punnett Square and how can they be used to predict traits? What is a mutation and how does it impact genes?
Who is Gregor Mendel? The father of Genetics, learn more about him by viewing his biography. Click image to open … https: //www. biography. com/video/gregor-mendel-mini-biography-35737667892
He did some experiments with pea plants What he learned helped to establish many of the rules of heredity • Click on the link to learn more… https: //www. youtube. com/watch? v=Yx. KFd. Qo 10 r. E&fea ture=youtu. be • • Study on Pea Plants
Mendel’s Laws Based on his research, Mendel developed 3 laws about heredity: The Law of Dominance The Law of Segregation The Law of Independent Assortment
A dominant trait is a trait whose appearance will always be seen in offspring. https: //www. youtube. com /watch? v=w 3 Cm. T 3 Wmt 3 g • The Law of Dominance
The Law of Segregation • A parent may have two distinct alleles for a certain gene, each on one copy of a given chromosome. • The law of segregation, states that these two alleles will be separated from each other during meiosis causing the two distinct alleles located on those chromosomes to separate apart from one another. Click on this link for a video example… https: //www. youtube. com/w atch? v=Fs 0 -STXp 7 NQ •
• https: //www. youtube. com/watch? v=q. IGXTJLr. Lf 8 The Law of Independent Assortment The law of independent assortment, states that the way an allele pair gets segregated into two daughter cells during the second division of meiosis has no effect on how any other allele pair gets segregated.
Click to open link… https: //florida. pbslearningmedia. org/resource/hew 06. sci. life. gen. mend elinherit/mendels-laws-of-genetic-inheritance/
Breaking it down Genes and Alleles Genes and Traits Dominant and Recessive Genes Genotypes and Phenotypes Using a Punnett Square The remainder of this unit will discuss in greater depth these concepts discussed in Mendel’s Laws Sex Linked Traits Mutations
Genes and Alleles Gene - Inside the DNA molecule are sections of information called genes. Each gene tells the cell how to make a certain protein which may determine a trait such as the color of the eyes. Allele - While the section of DNA is called a gene, a specific pattern in a gene is called an allele. For example, the gene would determine the hair color. The specific pattern of the hair color gene that causes the hair to be black would be the allele.
Click on link to play… https: //www. youtube. com/watch? v=pv 3 Kj 0 Uji. LE
https: //www. youtube. com/watch? v=YJHGfb. W 55 l 0 6 types of Inheritance. • • • Simple dominance Incomplete dominance Codominance X-linked Polygenic Inheritance Dihybrid Cross.
Traits In Genetics it is the study of how traits are passed from parent to offspring
https: //www. youtube. com/watch? v=Sldwz. OJ 23 J 8 What are traits? • A trait or character is a feature of an organism that is passed down from one generations to the next. • Click on the link to learn more…
What determines a trait? Traits are determined by the genes on the chromosomes. A gene is a segment of DNA that determines a trait.
Click the link to learn more about genes, traits and DNA… https: //learn. genetics. utah. edu/content/basics/dnathings
Read about traits at Tarheelreader. org… https: //tarheelreader. org/2009/10/22/trait s/
What do you think these traits are?
Here are more examples of traits
Complete the checklist to see what traits you have
Click link to read the article… consider questions below… What is “uncombable hair syndrome. ” How common is uncombable hair syndrome? What animals did scientist use to conduct hair experiments on? Discuss the conclusion of the experiment. https: //www. sciencenewsforstudents. org/artic le/scientists-find-genes-make-some-kids-hairuncombable
Genes and Traits • Coded in the chromosomes are genes which determine traits. • Depending on the pairing and order of the genes we have different traits.
Chromosomes and homologous pairs • • Chromosomes come in homologous pairs, thus genes come in pairs. Homologous pairs or matching genes one from female parent and one from male parent Example: Humans have 46 chromosomes or 23 pairs. One set from dad – 23 in sperm One set from mom – 23 in egg
Gene for eye color Blue Eyes Brown Eyes Alleles are different genes (possibilities) for the same trait ex: blue eyes or brown eyes Homologous pair of chromosomes
Dominant and Recessive Genes Gene that prevents the other gene from “showing” – dominant Gene that does NOT “show” even though it is present – recessive
Click the image to learn more…
Writing dominant and recessive genes Dominant gene upper case letter Recessive gene lower case letter
Let’s look at this example Example: • Straight thumb is dominant versus hitchhiker thumb • Straight thumb = HH • Straight thumb = Hh • Hitchhikers thumb = hh Always use the same letter for the same alleles Do not mix S = straight h = hitchhiker
Dominant and Recessive Genes Make a guess as to which would be the dominant and recessive gene for this litter of puppies?
Black dog BB – Black Bb – Black w/white gene Homozygous and Heterozygous Homozygous • Both genes of a pair are the same • Maybe referred to as purebred and can be dominant or recessive White dog bb – White Heterozygous • One dominant and one recessive gene • May be referred to as hybrid
For each genotype listed determine if the is heterozygous (He) or homozygous (HO) AA______ Ee ______ Ii______ MM ______ Bb ______ ff ______Kk ______Pp ______ DD ______HH ______dd ______LL ______ Cc ______ nn ______Qq ______RR ______
Genotype and Phenotype Genotype • Combination of genes an organism has (actual gene makeup) –Ex: TT, Tt, tt Phenotype • Physical appearance resulting from gene make-up (its what you see) Click image below for video link…
Punnett Square and Probability • Used to predict the possible gene makeup of offspring – Punnett Square Click the image above for step by step directions in creating and interpreting a Punnett Square… • Example: Black fur (B) is dominant to white fur (b) in mice • Cross a heterozygous male with a homozygous recessive female.
Your turn to practice… A green pea plant (Gg) is crossed with a yellow pea plant (gg). What is the probability that the offspring will be yellow? ________% green ________% yellow
Your turn to practice… A red flower (Rr) is crossed with a white flower (rr). What is the probability that the offspring will be red or white? ________% red ________% white
Click image to learn more about Mendel’s Model
Genetic Variations Click image to begin…
What determines if you are male or female? People have 46 chromosomes or 23 pairs 22 pairs are homologous (look alike) and are called autosomes. These determine body traits 1 pair is the sex chromosomes either an X or Y. How they combine determines if you are a male XY or female XX Male Female
Use the Punnett Square to determine probability parents having a boy vs. girl Mom is XX Dad is XY Chances baby is: ______girl ______boy
Learn more, click image below… Note that this video has a link to a video recap worksheet
Sex Linked Traits • If a gene is found only on the X chromosome and not the Y chromosome, it is said to be a sexlinked trait. Because the gene controlling the trait is located on the sex chromosome, sex linkage is linked to the gender of the individual. • Usually such genes are found on the X chromosome. • The Y chromosome is thus missing such genes
Hemophilia In humans, hemophilia is a recessive sex-linked trait (h). It is found on the X chromosome, not the Y. Males only have one X chromosome and have a much greater chance of having hemophilia. Females would have to be homozygous recessive in order to have hemophilia. This is when your blood will not clot. If you have this and get cut, it may take a long time for it to heal, or you may have internal bleeding.
• • Color Blindness This is the inability to distinguish between certain colors The most common type is red-green color blindness, where red and green are seen as the same color. Men are much more likely to be colorblind The most common, inherited color blindness are on the X chromosome
XN Xn X NX N X NX n X NY X n. Y Y Phenotype: Pull arrow for answer 2 normal vision females 1 normal vision male 1 colorblind male
Here are some examples of tiles used to test color blindness You should see 58 (upper left), 18 (upper right), E (lower left) and 17 (lower right).
What can you see? Click on the image and see if you can see the #’s
Down’s syndrome or Trisomy 21 7 chromosomes, extra chromosome at pair #21
Turner Syndrome They have only 45 chromosomes, missing a sex chromosome (X) Girls are affected and may have short, slow growth, heart problems, learning problems
Klinefelter Syndrome • Klinefelter syndrome is not inherited, and results from a random error called chromosomal nondisjunction leading to an extra X chromosome in males. • 47 chromosomes with an extra X chromosomes (XXY) • Boys affected and often not diagnosed until puberty. Symptoms may include weaker muscles, greater height, poor coordination, less body hair
Mutation are a sudden genetic change (change in base pair sequence of DNA) Harmful mutations – organism less able to survive: genetic disorders, cancer, death Mutations Beneficial mutations – allows organism to better survive: provides genetic variation Neutral mutations – neither harmful nor helpful to organism Mutations can occur in 2 ways: chromosomal mutation or gene/point mutation
Learn more about Mutations click image to play…
Click on video for an introduction to what cancer is and how it is the byproduct of broken DNA replication.
• Learn more about Cancer Cells and Mutaitons By the end of this tutorial, you should be able to explain the relationship between mutations, the cell cycle, and uncontrolled cell growth which may result in cancer.
Click on image to view this video where George Zaidan explains how rapid cell division is cancer's "strength" -- and also its weakness. Think about…. • How do cancer cells grow? • How does chemotherapy fight cancer (and cause negative side effects)?
Below are 2 ways scientist are learning from cancer.
Click on attachments at the cpalms link to open more resources Additional Cpalms Lesson on Cell Mutations and Cancer
Mutations in Plants Having an extra set of chromosomes is fatal in animals, but in plants it makes them larger and hardier.
Article and Discussion Questions click image to link… • What are family trees? • What is a chemical blueprint? • What are the segments of DNA that contain the instructions for making specific body proteins called?
Extension Activities click image to launch…
For additional resources click image…
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