Name: Nicholas Ireland Pd: 8 Genetics & Meiosis Test Review Guide GENETICS 1. Define the following terms: a. Allele: letter to represent the gene b. Dominant: trait that will take over no matter what c. Recessive: the trait that skips or taken over by the dominant allele d. Phenotype: physical traits e. Genotype: the allele combinations from your parents 2. In pea plants plant height displays a classic Mendelian inheritance pattern. Tall (T) is dominant to short (t). A. What is the genotype for a homozygous tall plant? TT B. What is the genotype of a heterozygous tall plant? Tt C. What is the genotype for a short plant? tt D. What are the two possible genotypes for a tall plant? TT,tt 3. In pea plants, tall (T) is dominant to short (t). A heterozygous tall pea plant is crossing with a short pea plant. A. What is the probability that one offspring will be Tt? 50% T t Tt t Tt t tt tt B. What is the phenotype ratio? 50/50 4. Does a Punnett square show you the actual outcome of the cross or just the probability of certain offspring? Explain. Shows the probability of each outcome not the real offspring. 5. What is the difference between a codominance and an incomplete dominance inheritance pattern? In codominance, both 6. What is an example given in class of codominance? What are the 3 phenotypes for each genotype? 7. Normal red blood cells (N) and sickled blood cells (S) are codominant alleles. When both alleles are inherited, the heterozygote (HNHS) displays both types of red blood cells TOGETHER (CO=TOGETHER) . A heterozygous individual (HNHS) and a heterozygous individual (HNHS) have a child. Determine the possible outcomes using a punnett square. A. What percentage will have all normal red blood cells ? ______ B. What percentage will have all sickled cells? _______ C. What percentage would we expect to have some sickle and some normal red blood cells? ________ 8. Snapdragons show an incomplete dominance pattern in flower color. Red (R) is incompletely dominant over white (W). If both alleles are inherited, a blended or intermediate phenotype of pink results (RW). A pink flower and a red flower are crossed. A. What percentage of offspring would we expect to be red?______ B. What percentage of offspring would we expect to be white? _____ C. What percentage of offspring would we expect to be pink? _____ For questions 9-14. Use the pedigree chart below. Some labels may be used more than once. Description Label 9. A male 10. A female 11. A marriage 12. A person who expresses the trait 13. A person who does not express the trait 14. A connection between parent and offspring 15. Does the pedigree to the right show an autosomal dominant or autosomal recessive trait? Explain, being sure to include all genotypes of the individuals in the pedigree. CHROMOSOMES AND MEIOSIS 16. What types of cells are diploid? ____________________________________ 17. What types of cells are haploid? ___________________________________ 18. A goldfish egg (gamete) has 50 chromosomes. How many chromosomes are found in the scale cell?_____ 19. How many divisions occur during meiosis?______ 20. What is the final product of meiosis? 21. Draw out a tetrad, aka a homologous chromosome pair crossing over---> Label sister chromatids, non sister chromatids, centromere, chromosome and homologous pair. 22. What shuffles genes and increases genetic variation in gametes during meiosis, when these homologous pairs are paired up? 23. What occurs during independent assortment? How does it increase genetic variation? 24. How does fertilization restore the diploid number of chromosomes? 25. What is random fertilization? 26. What is a zygote? 27. Compared to a somatic cell, a zygote has A. The same number of chromosomes B. Half the number of chromosomes C. Double the number of chromosomes 28. Which letter in Figure 1 represents meiosis? Why? 29. Which letter in Figure 1 represents fertilization? Why? 30. What is the difference between a haploid, diploid, and zygote? 31. Fill in the following table: 32a. Look at stage 1-2 of Meiosis I. What process is occurring that introduces genetic variation to the resulting gametes? Describe the process. 32b. In the image above, the initial cell begins with a diploid number of 4. Circle the first cell that becomes haploid from the overall process of meiosis. 33. Look at Karyotypes A and B. For each of the following statements below on the right, determine if the statement describes karyotype A, karyotype B, Both karyotypes, or neither karyotype. Statement Answer I would be from a diploid cell I would be from a sperm cell I would be from a skin cell I would be from an egg cell I am from a female’s cell 34. What might an abnormal human karyotype look like? You can give an example if you’d like. 35. How do abnormal karyotypes of an individual occur? 36. Identify whether each statement about asexual reproduction is TRUE or FALSE. ● Asexual reproduction does not increase genetic variation. ______ ● Asexual reproduction produces clones of the original cell. ______ ● Asexual reproduction does not require a mate for reproduction. _______ ● Sexual reproduction requires two gametes to fuse or combine________ 37. Name two similarities and two differences between meiosis and mitosis.
