2. What is meiosis? The process of forming gametes (sperm and egg) 4. Where does meiosis take place? Ovaries- eggs and testicles- sperm

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1 Name KEY Period Biology Review Standard 3 Main Idea Explain the significance of meiosis and fertilization in genetic variation. How I can demonstrate what a smart. Person I am 1. What is fertilization? 2 gametes with 23 chromosomes come together form a zygote with 46 chromosomes 2. What is meiosis? The process of forming gametes (sperm and egg) Compare the advantages/disadvantages of sexual and asexual reproduction to survival of species. 3. How is meiosis and mitosis different? Mitosis: somatic (normal) body cells & 46 chromosomes, end with two cells. Meiosis: gametes, 23 chromosomes and end with 4 cells. 4. Where does meiosis take place? Ovaries- eggs and testicles- sperm 5. What is a chromosome? structure of nucleic acids and protein found in the nucleus of most living cells, carrying genetic information in the form of genes. 6. What is a gene? basic physical and functional unit of heredity. Genes, which are made up of DNA, act as instructions to make molecules called proteins. 7. Advantages of Sexual Genetic variation, easier to adapt to environment 8. Disadvantage of Sexual Have to find mate, takes more time and energy Advantages of ASexual Quick, don t need to find a mate Disadvantages of Asexual Difficult to adapt, no genetic variety Formulate, defend, and 9.Define a mutation and what it might be caused by: support a perspective of a Changing of a gene. Caused by mistake by dna polymerase or an environmental mutagen bioethical issue related to intentional or unintentional chromoso mutations. Explain Mendel s laws of segregation and independent assortment and their role in genetic inheritance. 10. Define the following laws and explain how they increase genetic variation. Law of Segregation: two alleles coding for the same trait will separate from each other during meiosis. This way offspring will each acquire one copy of the trait from each parent. Law of independent assortment: g enes for one trait are not inherited with genes for another trait. Different traits an equal opportunity of occurring together.

2 Demonstrate possible results of recombination in sexually reproducing organisms using one or two pairs of contrasting traits in the following crosses: dominance/recessive, incomplete dominance, codominance, and sex-linked traits. 11. What is phenotype? Physical expression of a gene 12. What is genotype? The different genes an organism carries 13. Define Dominant: What will be expressed as the phenotype over the recessive. 14. Define Recessive: Phenotype that can be masked by the dominant allele. 15.In dogs, there is a hereditary deafness caused by a recessive gene, d. A kennel owner has a male dog that she wants to use for breeding purposes if possible. The dog can hear, so the owner knows his genotype is either DD or Dd. If the dog s genotype is Dd, the owner does not wish to use him for breeding so that the deafness gene will not be passed on. This can be tested by breeding the dog to a deaf female (dd). Draw the Punnett squares to illustrate these two possible crosses. In each case, what percentage/how many of the offspring would be expected to be hearing? deaf? D d D D d Dd dd d Dd Dd d Dd dd d Dd Dd 50% hearing, 50% deaf 100% hearing, 0% deaf

3 16. Also, using a Punnett square, show how two hearing dogs could produce deaf offspring. Each would have to be heterozygous. 17. SpongeBob loves growing flowers for his pal Sandy! Her favorite flowers, Poofkins, are found in red, blue, and purple. Use the information provided and your knowledge of incomplete dominance to complete each section below. 1. Write the correct genotype for each color if R represents a red gene and B represents a blue gene. Red - _ RR Blue - _ _BB Purple - _ _RB 2. What would happen if SpongeBob crossed a Poofkin with red flowers with a Poofkin with blue flowers. Complete the Punnett square to determine the chances of each flower color. (a) Give the genotypes and phenotypes for the offspring. (b) How many of the plants would have red flowers? 0 % (c) How many of the plants would have purple flowers? _100 % (d) How many of the plants would have blue flowers? 0 % 3. What would happen if SpongeBob crossed two Poofkins with purple flowers? Complete the Punnett square to show the probability for each flower color. (a) Give the genotypes and phenotypes for the offspring. (b) How many of the plants would have red flowers? 25 % (c) How many of the plants would have purple flowers? _50 % (d) How many of the plants would have blue flowers? 25 %

4 4. What would happen if SpongeBob crossed a Poofkin with purple flowers with a Poofkin with blue flowers? Complete the Punnett square to show the probability for plants with each flower color. (a) Give the genotypes and phenotypes for the offspring. BB 50%, BR 50%. Blue 50%, Purple 50% (b) If SpongeBob planted 100 seeds from this cross, how many should he expect to have of each color? Purple flowers - 50 Blue flowers - 50 Red flowers - 0 Relate Mendelian principles to modern-day practice of plant and animal breeding 18. Tell me how selective breeding of plants and animals using Mendel's principles of inheritance affects us: We breed plants and animals to fit our needs. Farming for meat, any seedless fruit. 19. What is a major drawback to selective breeding? (think about dogs) Decrease genetic variability. Can lead to inbreeding and illness. Unhealthy.

5 Use a model to describe the structure of DNA. Fill in the blanks: DNA is a double helix, in the nucleus, and has a t instead of a u that pairs with at. Double helix because two strands wrap around in a spiral. Explain the importance of DNA replication in cell reproduction. Summarize how genetic information encoded in DNA provides instructions for assembling protein molecules. 22. Why must a cell replicate the DNA in cell reproduction? We want each new cell to have 46 chromosomes (a normal amount of DNA) 23. What is the process for protein synthesis? Fill in the blanks below: DNA is located in the nucleus. DNA gets trans_transcribed into mrna.

6 RNA leaves the nucleus. RNA molecules are single stranded. Thymine is replaced by U_uracil. RNA travels to the ribosome in a cell where trans translation Takes place. This is where RNA provides the code for amino acids to be translated into a proteins which does all the work in our body. Enzymes are an example of a protein. Describe how mutations may affect genetic expression and cite examples of mutagens. 24. What does trna do? Bring amino acids to the ribosome 25. What is a mutagen? Anything that can cause a mutation in DNA 26.Give an example of two mutagens. Accutane, radioactive waste, UV light, etc. 27.How does a mutagen alter genetic material? Causes bases to be mismatched. Destroys parts of DNA. Relate the historical events that lead to our present understanding of DNA to the cumulative nature of science knowledge and technology. 28. Describe how historical events have led to our present understanding of DNA. Use the words: KNOWLEDGE; TECHNOLOGY; MENDEL; WATSON AND CRICK; FRANKLIN. Describe the effects of environmental factors on natural selection. 29.What is natural selection? the process whereby organisms better adapted to their environment tend to survive and produce more offspring. 30.Give an example how a change in environment may stress an organism: New predator, water source drying up, change in weather 31. An organism is able to survive the changed environment, what can it do that others cannot? Adapt Relate genetic variability to a species potential for adaptation 32.Explain why a species with the greatest variation in their genetic material will have the greatest potential for adaptation:

7 to a changing environment. Population can have multiple alleles that may become useful in overcoming future environmental stresses. Relate reproductive isolation to speciation. 33.Reproductive isolation can occur several ways, describe 2 ways how: Gametic isolation: sperm can t fertilize egg If sperm can fertilize egg, offspring is unhealthy/sterile 34.Geographic or Habitat Isolation: physical space that separates organisms, like a river or canyon. 35.Reproductive Behaviors: Wont mate without specific behavior, like a dance 36.What is a species?: breed together and have healthy offspring Cite evidence that supports biological evolution over time 37.How does the fossil record show evidence of evolution? shows changing populations over time 38.How does similarities in DNA show evidence of the fossil record? Shared DNA = shared history 39.What are homologous structures? How does homologous structures show evidence of evolution? A homologous structure is an example of an organ or bone that appears in different animals, underlining anatomical commonalities demonstrating descent from a common ancestor. 40.What is a vestigial structure? Structure that once had a function, but no longer does. Identify the role of mutation and recombination in evolution. Relate the nature of science to the historical development of the theory of evolution 41.Explain how Mutations help provide the variation in genetic material that natural selection depends on: It can create new alleles 42.Science conclusions are tentative and therefore never final. What do we do when we have new evidence that doesn t fit our current accepted theory or model? We change it! 43.Scientific conclusions are based on the assumption that natural laws operate today as they did in the past and that they will continue to do so in the future. Give an example of this: Gravity, superposition

8 44. When we use the word theory, what does that mean? well-substantiated explanation of some aspect of the natural world, based on a body of facts that have been repeatedly confirmed through observation and experiment.