Laboratory Study Guide,

Preparation: Inheritance in Drosophila
Inheritance in Drosophila

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Preparation: Inheritance in Drosophila, pp 1-2.
Inhderitance in Drosophila, pp. 1-6.

Terms to Know in This Chapter:

egg (sing.)

larva (sing.) [LAR vah]

larvae (pl.) [LAR vee]

pupa (sing.) [PUU pah]

pupae (pl.) [PUU pee]

molt

hook (sing.)

spiracle (sing.) [SPIRE ah kul]

instar (sing.) [IN star]

Instant Drosophila Medium [dro SOF eh lah]

yeast

genotype (sing.) [GIN oh type]

phenotype (sing.) [FEN oh type]

sex comb (sing.)

abdomen (sing.) [AB do men]

wild type

chromosome (sing.) [CROW moe zome]

sex-linked inheritance

X chromosome

dominant [DOM eh nant]

recessive [ree SESS ive]

allele (sing.) [ah LEEL]

haploid [HAP lloyd]

diploid [DIP lloyd]

autosomal [aw toe ZOME al]

red eye

white eye

normal

vestigial [ves TIGE ee ul]

Y crhomosome

mutation (sing.) [mew TAY shun]

homozygous [hoe moe ZIE gus]

heterozygous [het er oh ZIE gus]

hybrid (sing.) [HIGH brid]

parental generation

first filial generation [FILL ee ul]

second filial generation

ether [EE thur]

etherizer (sing.) [EE thur rize er]

observed

expected

goodness of fit

chi square [KIE]

degrees of freedom

hypothesis (sing.) [high POTH eh siss]

hypotheses (pl.) [high POTH eh seez]

probability [prob ah BILL ah tee]

deviation [dee vee AY shun]

+vgX^wY

+vgX⁺X⁺

Genera You Need to Know

Drosophila [drow SOF eh lah]

People You Need to Know

Thomas Hunt Morgan

What You Need to Know:

You should be able to:

1. sex fruit flies,
2. describe the life cycle and stages of a fruit fly,
3. rear fruit flies for lab,
4. anestitize fruit flies and separate them according to eye color and wing type,
5. distinguish between homozygous and heterozygous; phenotype and genotype; dominant and recessive; sex-linked and autosomal, and
6. count your flies, calculate expected versus observed ratios and calculate chi-square values for your F₂ generation.

Exercises: Fill in the Blank.

1. The diploid number of chromosomes for fruit flies is .
2. There are two methods of sexing fruit flies. One is to look at the abdomens. Males have a smaller, more compact, less colored abdomen. The other way is to look for .
3. ++X^wY would indicate a fruit fly.
4. What is the stage between molts? .
5. From egg to adult takes approximately days.
6. What is meant by wild type in wings? .
7. If there are 8 phenotypic classes, how many degrees of freedom would you use?
8. What would the result of a cross between a vestigial wing, red-eyed female with a normal winged (homozygous), white-eyed male? .
9. Assuming your F₂ cross, out of 500 flies, how many should be expected with vestigial wings and red eyes?
10. If your chi-square value is higher than 7.815, what has occured? .
11. The square of the deviation divided by the expected equals .
12. What stage of the life cycle crawls up on the surface of the glass and incubates?

Exercises: Multiple Choice. Select the Best Answer.

1. The stage between molts is called
   

   (1) eggs.
   

   (2) larvae.
   

   (3) pupae.
   

   (4) adults.
   

   (5) instars.

2. If you have 1000 fruit flies in your F₂ cross in lab, how many should be normal winged, red-eyed?

   (1) 1000
   

   (2) 562.5
   

   (3) 93.75
   

   (4) 62.5
   

   (5) Cannot be calculated from the above information.

3. If your chi-square value is 6.064 and your degrees of freedom is 4, what is the possibility that the event occurred strictly through chance and not some outside influence?
   

   (1) 30%
   

   (2) 70%
   

   (3) 80-90%
   

   (4) 70-80%
   

   (5) 30-50%

4. Which would represent a vestigial female with red eyes?
   

   (1) ++X^wX^W
   

   (2) +vgX^WY
   

   (3) vgvgX^WX^w
   

   (4) wwX⁺X⁺
   

   (5) None of the above.

5. A red-eyed female with normal wings would be called a(n)
   

   (1) genotype.
   

   (2) phenotype.
   

   (3) homozygous.
   

   (4) heterozygous.
   

   (5) haploid.