TLS Online TPP Program

#Question id: 7154


Cancer is believed to often arise from stem cells, rather than fully differentiated cells. Which of the following are consistent with this view?

#Unit 4. Cell Communication and Cell Signaling
  1. Stem cells are actively dividing and express few differentiated functions, so they may have fewer changes to undergo than do fully differentiated cells in becoming cancer cells.
  2. DNA replication is necessary for mutations to occur, and stem cells are replicating their DNA whereas differentiated cells are for the most part not replicating their DNA.
  3. Teratocarcinomas are tumors that arise from germ cells or embryonic stem (ES) cells, under certain circumstances, demonstrating that tumors can arise from stem cells without further mutation.
  4. All of the above are reasons that cancer cells may more readily arise from stem cells than from fully differentiated cells.
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TLS Online TPP Program

#Question id: 15379

#Unit 8. Inheritance Biology

What are the possible offspring from a type A mother and a type AB father?

TLS Online TPP Program

#Question id: 15378

#Unit 8. Inheritance Biology

You find a pink geranium in your flowerbed of red geraniums. Seeds from self fertilization of this plant produce ¼ red plants, ½ pink plants, and ¼ white plants. When considering the visible phenotype, which explanation is most likely?

TLS Online TPP Program

#Question id: 15194

#Unit 8. Inheritance Biology

 Genes that control coat color in mammals represent some of the best early examples of genes with multiple alleles exhibiting different phenotypes. A classic example is the C gene in hamsters. Three of the known alleles of this gene are C, ca and ck. Each supplies a different amount of black pigment to the coat hair. The phenotypes of three different homozygous strains are as follows.

would mate the true-breeding  ca ca  hamsters to the true-breeding ck ck  hamsters to produce heterozygous  ca and ck  F1 progeny,  the F1 progeny cack  hamsters self fertilized, From the fraction of F2 progeny that have the wild type black phenotype, 

Crosses and their interpretation that would have allowed geneticists to come to the conclusion that ca and ck were likely to be alleles of the different gene. 
What will be the ratio of F2 hamster;

TLS Online TPP Program

#Question id: 15193

#Unit 8. Inheritance Biology

Genes that control coat color in mammals represent some of the best early examples of genes with multiple alleles exhibiting different phenotypes. A classic example is the C gene in hamsters. Three of the known alleles of this gene are C, ca and ck. Each supplies a different amount of black pigment to the coat hair. The phenotypes of three different homozygous strains are as follows.
would mate the true-breeding  ca ca  hamsters to the true-breeding ck c hamsters to produce heterozygous  ca and ck  F1 progeny. Crosses and their interpretation that would have allowed geneticists to come to the conclusion that ca and ck were likely to be alleles of the same using the concept that alleles of the same gene will be tightly linked. What will be the ratio of F2 hamster;

TLS Online TPP Program

#Question id: 15192

#Unit 8. Inheritance Biology

Genes that control coat color in mammals represent some of the best early examples of genes with multiple alleles exhibiting different phenotypes. A classic example is the C gene in hamsters. Three of the known alleles of this gene are C, ca and ck. Each supplies a different amount of black pigment to the coat hair. The phenotypes of three different homozygous strains are as follows.
Based on the concepts of recessivity, determine whether ck and ca were dominant or recessive alleles by crossing the true-breeding albino hamsters  with the true-breeding sepia hamsters. From the resulting F1 progeny phenotype, what would be the ratio of F2 phenotype

TLS Online TPP Program

#Question id: 15191

#Unit 8. Inheritance Biology

Genes that control coat color in mammals represent some of the best early examples of genes with multiple alleles exhibiting different phenotypes. A classic example is the C gene in hamsters. Three of the known alleles of this gene are C, ck and ca. Each supplies a different amount of black pigment to the coat hair. The phenotypes of three different homozygous strains are as follows.
Based on the concepts of dominance, determine whether ck and ca were dominant or recessive alleles by crossing the true-breeding sepia hamsters to true-breeding black hamsters. From the resulting F1 progeny phenotype, what would be the ratio of F2 phenotype