Genetics Practice Problems Genetics Practice Problems You may type in your own answers, then check to see if you were right. If you’re totally stumped, you can tell the computer to show you the answer to a particular question. Monohybrid Cross: In humans, brown eyes (B) are dominant over blue (b)*. A brown-eyed man marries a blue-eyed woman and they have three children, two of whom are brown-eyed and one of whom is blue-eyed. (* Actually, the situation is complicated by the fact that there is more than one gene involved in eye color, but for this example, we’ll consider only this one gene.) Testcross: In dogs, there is an hereditary deafness caused by a recessive gene, “d.” Incomplete Dominance: Note: at least one textbook I’ve seen also uses this as an example of pleiotropy (one gene – multiple effects), though to my mind, the malaria part of this is not a direct “effect” of the gene. A photo, taken by Dr. Dihybrid Cross: If the man is both Rr and Tt (How do we know that?) Multiple Alleles and Codominance: Ms. Epistasis:
Harry Potter's World Renaissance Science, Magic, and Medicine - Science Learning Outcomes Background Information Vocabulary Materials Pre-Lesson Lesson 1 Lesson 2 Evaluations Extension Standards Grade Level: 7th-11th grades Time Needed: Four 40-minute class periods for younger students with little knowledge of genetics (two periods for Pre-lesson Activity and Lesson 1, and the other two periods for Lesson 2) Two 40-mintue class periods for older students with strong knowledge of genetics (one period for Pre-lesson Activity and Lesson 1 and the second period for Lesson 2) Description: The purpose of this lesson is to give students an introductory understanding of genetic inheritance. Note: The purpose of this lesson is to give students an introductory understanding of genetic inheritance. Learning Outcomes Students will be able to: Define the basic genetic terms and concepts— DNA, chromosome, gene, allele, homozygous, heterozygous, recessive and dominant genes, genotype, phenotype, and Medelian inheritance. Back to top Background Information J. Vocabulary Materials
Cracking the Code of Life Cracking the Code of Life PBS Airdate: April 17, 2001 ROBERT KRULWICH: When I look at this—and these are the three billion chemical letters, instructions for a human being—my eyes glaze over. But when scientist Eric Lander looks at this he sees stories. ERIC LANDER (Whitehead Institute/MIT): The genome is a storybook that's been edited for a couple billion years. ROBERT KRULWICH: This is the story of one of the greatest scientific adventures ever, and at the heart of it is a small, very powerful molecule, DNA. For the past ten years, scientists all over the world have been painstakingly trying to read the tiny instructions buried inside our DNA. J. FRANCIS COLLINS (National Human Genome Research Institute): This is the ultimate imaginable thing that one could do scientifically...is to go and look at our own instruction book and then try to figure out what it's telling us. ROBERT KRULWICH: And what it's telling us is so surprising and so strange and so unexpected. I'm Robert Krulwich. DR.
Geniverse Research Overview Geniverse research is being led by our research partner, BSCS, with assistance from our evaluator partner, TERC. Our research study is examining how the Geniverse materials affect students’ genetics content knowledge and abilities to engage in scientific argumentation. The research study began in the fall of 2012 with 48 teachers. An added feature of our research design is the ability to avoid measuring implementation dip – that is, the effects of immature implementation often measured in randomized experiments. Student Outcome Measures Student Content Knowledge Our primary measure of student achievement employs two sets of test questions. For the proximal items, we looked closely at each Geniverse learning goal and activity, and developed or identified items that aligned with each. For the distal items, we are using an instrument by Tsui and Treagust (2010) designed to diagnose scientific reasoning in genetics. Motivation Argumentation Other Measures
Sleep & Gene Expression Photo Credit: Clipart.com Just one week of sleep deprivation alters the expression of at least 711 different genes. Transcript Sleep loss affects gene function. I’m Bob Hirshon and this is Science Update. Just one week of mild sleep deprivation affects the function of 711 different genes. Archer:The changes are quite large, and they’re comparable to the kinds of differences that you would see if you were to compare, for example, a normal tissue with a diseased tissue. Genes linked to inflammation and stress increased their activity in sleep-deprived people, while master control switches that regulate the whole body became sluggish. Making Sense of the Research It's well known that sleep deprivation can have a wide range of effects, including irritability and depression, memory and cognitive deficits, impaired driving skills, and a higher risk of obesity, cardiovascular disease, and possibly even some kinds of cancer. But those instructions aren't always carried out in the exact same way.
Genetic Disorders Road salt can change sex ratios in frog populations: Naturally occurring leaf litter can also alter sex outcomes -- ScienceDaily Naturally occurring chemicals found in road salts commonly used to de-ice paved surfaces can alter the sex ratios in nearby frog populations, a phenomenon that could reduce the size and viability of species populations, according to a new study by scientists at Yale and Rensselaer Polytechnic Institute (RPI). The researchers found that the proportion of females within tadpole populations was reduced by 10 percent when exposed to road salt, or sodium chloride, suggesting that the salt has a masculinizing effect. They also found that exposure to fallen oak leaves also significantly altered the sex ratios in the frog populations, as well as the size of individual females in some cases. Maple leaf litter, on the other hand, had no effect. More than 22 million metric tons of road salt is applied to roads in the United States each year. The results were published in the Canadian Journal of Fisheries and Aquatic Sciences.
New Genetic Twist: 4-Stranded DNA Lurks in Human Cells Sixty years after scientists described the chemical code of life — an interweaving double helix called DNA — researchers have found four-stranded DNA is also lurking in human cells. The odd structures are called G-quadruplexes because they form in regions of deoxyribonucleic acid (DNA) that are full of guanine, one of the DNA molecule's four building blocks, with the others being adenine, cytosine, thymine. The structure comprises four guanines held together by a type of hydrogen bonding to form a sort of squarelike shape. (The DNA molecule is itself a double strand held together by these building blocks and wrapped together like a helix.) The new visualization of the G-quadruplex is detailed this week in the journal Nature Chemistry. "I think this paper is important in showing directly the existence of this structure in vivo in the human genome, but it is not completely unexpected," said Hans-Joachim Lipps, of the University of Witten in Germany, who was not involved in the study.
Study of Holocaust survivors finds trauma passed on to children's genes | Science Genetic changes stemming from the trauma suffered by Holocaust survivors are capable of being passed on to their children, the clearest sign yet that one person’s life experience can affect subsequent generations. They also analysed the genes of their children, who are known to have increased likelihood of stress disorders, and compared the results with Jewish families who were living outside of Europe during the war. “The gene changes in the children could only be attributed to Holocaust exposure in the parents,” said Yehuda. Her team’s work is the clearest example in humans of the transmission of trauma to a child via what is called “epigenetic inheritance” - the idea that environmental influences such as smoking, diet and stress can affect the genes of your children and possibly even grandchildren. The idea is controversial, as scientific convention states that genes contained in DNA are the only way to transmit biological information between generations.