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Genetics questions

Genetics as it applies to evolution, molecular biology, and medical aspects.

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Genetics questions

Postby Grace » Fri Dec 03, 2004 2:39 am

My biology teacher has given us a take-home-exam. He doesn't care how we get the answer (think pizza party, asking doctors), and here is part of the section i would appreciate any help on at all.

*The answers of these questions are supposed to be either a sentence or a word.*

76. When a red four o'clock plant was crossed with a four o'clock plant they produced pink four o'clock plants. Can you explain why?

77. If a color blind man marries a woman whose flower was color-blind, what is the probability for their first child being color-blind?

78. Our famous math teacher Mr. Stork noted that genetic traits for seeds are noted as follows: L = long, w = wrinkled, R= ribbed, l=short, W=smooth, y=white, r=grooved. what would be the genotype for a short, wrinkled, yellow, grooved seed?

79. a smaller number of genes in the X Chromosomes are of the dominant type. in these conditions a father will transmit the genes and resulting condition to?

80. In Drosophilia, the gene for eye color is on the X chromosome. red eye color is dominant over white eye color. What would be the result on the progeny?

81. Most chemical reactions in living things are dependent of?

82. Construct a diagram of the structure formula for the building block of an amino acid

83. Enzymes are composed of?

84. Meiosis is important because it?

85. What was the stimulus, which led Mendels research in plant breeding?

86. Unlike pea plants, corn may be self-or-cross pollinated by pollen dispersed by the wind. What methods would have to be used to insure that corn kernels would be hybrids?

87. Why would offspring of families with a history of diabetes mellitus on both the mother’s and father’s side be more likely to develop the disease than offspring of families in which diabetes had occurred only on one parents side of the family?

88. Two white sheep produce a black offspring. What must the parents’ genotype for color be? What is the possibility that the next offspring will be back?

89. What kind of gametes would be produced by organism having the following genotypes?

A) AaBB B) aaBB C) AAbb D) AaBBCc

90. How can you account for the fact that in some cases organisms of the same phenotype are not of the same genotype? How can you account for cases of organisms with the same genotype but different phenotypes?

91. An extra finger in man occurs rarely. It is due to a dominant gene. Suppose one parent is normal and the other parent has an extra finger, but is heterozygous for the trait. What is the probability that their next child will be normal for color? (Use a diagram to show your results) F = dominant, f = recessive.)

92. Albinism (lack of pigment) in man is caused by recessive gene. If normal parents have an albino child, what is the probability that their next child will be normal for color? (Use a diagram to show your results) A = dominant, a= recessive.)

93. If a woman who is not a carrier for hemophilia is married to a man who is a hemophiliac. What percentage of their male offspring could be expected to be hemophiliacs?

94. Suppose that the nucleus I removed from a cell. How would this affect the ability fo the cell to synthesize new protein?

95. What causes biologists to suspect that chromosomes are involved in the transmission of hereditary material?

96. Why is it not possible for a male to be heterozygous for color blindness?

97. Three babes were recently mixed up at your local hospital. The blood types of the parents and babies are shown below. Determine which baby belongs to which parents. Construct a blood type genotype graph to verify your choices.

Parents Parents I Parents II Parents III

A and B A and A AB and O

Baby 1= B Baby 2= O Baby 3= AB

98. Red fruit is dominant to yellow fruit (R = dominant; r = recessive) in tomatoes. Tallness (T) is dominant to shortness (t) in these plants. What phenotype and genotype ratios would you predict for the offspring of parent plants, one of which is red homozygous and tall homozygous, and the other of which is red heterozygous and tall heterozygous?

99. Suppose you were a cat fancier and were raising what you thought was a pure-bred line. Then you found that some of the cats had sports of white hair at the tips of their tails, while others did not. How would you determine whether this trait is recessive or dominant? (Assume that only one pair of genes is affecting this trait.)

100. Assume the ability to roll the tongue is dominant to the lack of this ability. Mr. and Mrs. Jones could roll their tongues. They had a daughter, Sally, who was unable to roll her tongue. Mr. Smith could roll his tongue, but Mrs. Smith could not. They had a son, John, who could roll his tongue; Mrs. Smith and Mr. Jones, died. Mr. Smith married Mrs. Jones. They had a daughter, Mary, who could roll her tongue. What were the genotypes of all of the individuals involved?
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Postby njyothi_2000 » Fri Dec 03, 2004 11:40 am

here r answers 2 very few q
i will get back 2 the rest of the questions

76.incomplete dominance
77.3 of the 4 children will be color blind or carriers of color blindness.the first child will be 100% colorblind.the ratio color blindness :non color blindness is 3:1
80.all red
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Postby Grace » Sat Dec 04, 2004 1:27 am

Many Thanks!

Any more help would be deeply appreciated!
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Postby biostudent84 » Sat Dec 04, 2004 2:42 am

76. Partial dominance
77. (Assuming you meant father, not flower) 1 in 2
78. llwwYyrr or llwwYYrr
79. If the father carries the dominant gene...yes if the child is female, no if the child is male.
80. Females: Red
Males: Red or White (red if the gene does make it through reproduction)
81. Enzymes
................. |
83. Proteins!!
84. Halves the number of chromosomes to allow sexual reproduction
85. Peas!
86. Not sure exactly what he's asking there...hybrids is when an organism has both a dominant and a recessive gene
87. More of a chance of two recessive genes coming together and causing diabetes mellitus.
88. W=white w=black
Mother: Ww
Father: Ww
Offspring: ww
Next generation: Odds are 1 in 2
89. A: AB, aB
B: aB
C: Ab
D: ABC, aBC, ABc, aBc
90. A: Aa and AA genotypes will both have the phenotype of A
B: The same phenotype codes for brown and black hair...envornmental variables makes one have more pigment, and thus, black hair.
91. Probability is 1 in 4 or 1 to 3 (both mean the same thing)
92. 3 in 4 or 3 to 1 (both mean the same thing)
Note: I am not talented enough to make the boxes need to look it up how to do them.
93. 50%
94. mRNA could not be formed, therefore the ribosomes would have no programming to synthesize new proteins.
95. Chromosomes are made up of DNA, and chromosomes are the only things that are randomly recombined at reproduction.
96. (double check this one) It is a gene only on the X chromosome. A male cannot have 2 X chromosomes ;)
98. RRTT, RrTt parents
Potential children
All offspring will be tall and red
Information you were given by your instructor should allow you to get the ratios
99. If more cats had white-tips than non-white, then the trait is dominant. If not, recessive.
100. A-able a-unable
Mrs. Smith: Aa
Mr. Smith: Aa
Sally: aa
Mrs. Jones:Aa
Mr. Jones: Aa
John: AA
Mary: Aa
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Postby Poison » Fri May 20, 2005 9:18 pm

I haven't heard the term 'partial dominance'. is the same as incomplete dominance?
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Postby b_d_41501 » Sat May 21, 2005 1:34 am

I think i've read somewhere before that partial dominance is a synonym for incomplete dominance
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Postby MrMistery » Sat May 21, 2005 10:02 am

Yes, that is true b_d_41501
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Postby Poison » Sat May 21, 2005 5:15 pm

Thanks... :)
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How charged with punishment the scroll
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Re: Genetics questions

Postby anutheprincess2 » Fri Sep 15, 2006 7:42 am

86-the stimilus which lead mendel to search on plant breeding was that when he found two pea plants having different seed colours(yellow and green) in his monastery
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Postby dianne » Thu Sep 21, 2006 10:57 am

76. I think the red and white four o'clock plant became red because of codominance. Codominance happens when two dominant trait are interbreed.
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Postby dianne » Thu Oct 05, 2006 4:28 am

76. incomplete dominance, the dominant genes are partial.


84.meiosis is important bcoz it reduces d number of choromosomes to have 23 pairs

88.Rr and Rr
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Postby ainala8055 » Tue Oct 13, 2009 10:14 am

97) Baby3 belongs to parent1.(AB,AO,BO,OO)
Baby2 belongs to parent2.(AO,OO)
Baby1 belongs to parent3.(AO,BO)
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