Mer Scott
Quiz by , created more than 1 year ago

Identify causes of deviations from simple Mendelian ratios. • Discuss how environmental factors may affect phenotype. • Explain how single genes can affect numerous phenotypic traits. • Explain that some phenotypic traits are affected by several loci.

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Mer Scott
Created by Mer Scott over 7 years ago
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L24 Extensions of Mendelian genetics

Question 1 of 10

1

If two events are of each other, we use the product rule, and their probabilities.

Drag and drop to complete the text.

    independent
    multiply

Explanation

Question 2 of 10

1

What is the probability of getting an AaBbcc offspring from the cross of Aa BB Cc x Aa Bb cc?

Select one of the following:

  • 50%

  • 25%

  • 12.5%

Explanation

Question 3 of 10

1

If you observed a 2:1 ratio for a gene in offspring, what could you assume?

Select one of the following:

  • One allele combination is lethal and so is never observed.

  • One allele combination never leads to a phenotype.

  • One allele combination is very rare.

Explanation

Question 4 of 10

1

Greater polymorphism in a population can be advantageous for survival and evolution.

Select one of the following:

  • True
  • False

Explanation

Question 5 of 10

1

Choose the incorrect statement about Incomplete Dominance.

Select one of the following:

  • Both alleles appear to be expressed equally by all cells, showing an intermediate phenotype which is neither.

  • A cross between two F1 individuals with a blended appearance of alleles will produce offspring in a 1:2:1 ratio, where 50% of the offspring have the phenotype of a blended appearance and the other 50% display single alleles.

  • It proves the blending inheritance theory.

Explanation

Question 6 of 10

1

Which statement best describes co-dominance?

Select one of the following:

  • Both alleles are expressed on the phenotype at the same time.

  • Neither alleles appear to be expressed on the phenotype, but instead an intermediate between them is seen.

Explanation

Question 7 of 10

1

The ABO blood antigen system is a good example of:

Select one of the following:

  • incomplete dominance

  • co-dominance

Explanation

Question 8 of 10

1

Epistasis describes the situation where one gene the action of another. Hence, if the gene to produce one enzyme in a is damaged or ineffective, the next enzyme and gene in the chain may be perfectly but will never produce an end product because their precursor is dysfunctional. The second gene is said to be under of the first.

Drag and drop to complete the text.

    affects
    metabolic pathway
    functional
    epistatic control

Explanation

Question 9 of 10

1

Select from the dropdown lists to complete the text.

A phenotype controlled by many genes which have an additive effect is known as a ( polymorphic, polygenic ) trait, and example being ( skin colour, weight, or height etc., eye colour, hair colour, etc. ).

Explanation

Question 10 of 10

1

What is pleiotropy?

Select one of the following:

  • One gene having many phenotypic affects.

  • One gene affecting many other genes.

  • Many genes affecting the phenotype in a summative way.

Explanation