Meiosis and Genetics Review
1. What are offspring that result from crosses between parents with different traits called? hybrid
2. What are the chemical factors that determine traits? genes
3. What did Gregor Mendel conclude about how traits are inherited? Inherited through the passing of
factors from parent to offspring.
4. What does the principle of dominance? Some alleles are dominant and others are recessive.
5. Why were all offspring tall when Mendel crossed true-breeding tall plants with true-breeding short
plants? The allele for tall plants is dominant.
6. When you flip a coin, what is the probability that it will come up tails? 1/2
7. Organisms that have two identical alleles for a particular trait are said to be homozygous.
8. In a cross between Tt x TT, what is the phenotypes of the offspring? All are expected to be tall.
9. What principle states that during gamete formation genes for different traits separate without
influencing each other’s inheritance? Principle of Independent Assortment
10. Situations in which one allele for a gene is not completely dominant over another allele for that
gene are called incomplete dominance.
11. A cross of a woman with type A blood and a man with type B blood produces a child with type AB
blood. This type of inheritance is known as codominance.
12. If an organism’s diploid number is 12, its haploid number is 6.
13. How many alleles are in each gamete and where are they inherited from? one allele for each gene.
14. Gametes are produced by the process of meiosis.
15. What is shown in the figure below? Crossing-over
Meiosis and Genetics Review
16. Chromosomes form tetrads during prophase I stage of meiosis.
17. Unlike mitosis, meiosis results in the formation of haploid or diploid cells? Haploid cells
18. Unlike mitosis, meiosis results in the formation of four genetically different cells.
19. Linked genes are found on the same chromosome.
20. If two genes are on the same chromosome and rarely assort independently, the genes are probably
located close to each other.
21. Draw the circle diagram of meiosis.
N
N
2N
N
N
22. What types of cells are produced by meiosis? Gamete, aka sex cells or egg and sperm
23. The different forms of a gene are called alleles.
24. Probability is the likelihood that a particular event will occur.
25. If you flip a coin five times and it comes up head each time, the probability that it will come up
heads the next time is 1/2.
26. What are the possible phenotypes of the offspring of the cross between Tt x TT? Tall and short
Meiosis and Genetics Review
27. What is the expected genotype ratio of the offspring of the cross between Tt x TT? 1 TT: 2 Tt: 1 tt
28. An organism’s gametes have half the number of chromosomes found in the organism’s body cells.
29. Crossing over occurs during the stage of meiosis called prophase I.
30. In the figure above, what is the genotype of the pink-flowered snapdragons? RI
31. Explain whether the alleles in the figure about show dominance, incomplete dominance, or
codominance. The alleles show incomplete dominance, because a cross between red-flowered
snapdragons and ivory-flowered snapdragons produces snapdragons with an in-between trait—pink
flowers.
32. According to the figure above, if red-flowered snapdragons and ivory-flowered snapdragons are
crossed, what percentage of their offspring would be expected to be pink-flowered? One hundred
percent of the offspring would be expected to be pink-flowered.
33. According to the figure above, if two pink-flowered snapdragons are crossed, what percentage of
their offspring would be expected to be pink-flowered? Fifty percent of the offspring would be
expected to be pink-flowered.
Meiosis and Genetics Review
34. In the figure above, what is the structure labeled X in stage A? The structure is a tetrad.
35. If the stages shown in the above figure are taking place in a female animal, how many eggs will
result from stage G? Explain your answer. One egg will result. One of the four haploid cells will form
an egg. The other three will form polar bodies.