Ch.3_TEACHER-led

Each protein molecule in the body is synthesized under the direction of a(n):

• Zygote

• Gene.

• Amino acid.

• Enzyme.

What differentiates monozygotic from dizygotic twins?

Suppose a researcher carries out a Mendelian study, beginning with two purebred strains of the same species of plant. One strain produces red flowers, the other yellow. The researcher crosses the strains and finds that all of the resulting plants have red flowers. What should the researcher get when they breed these offspring among themselves? (feel free to draw out punnet squares)

• All plants should have red flowers.

• All plants should have yellow flowers.

• Half the plants should have red flowers, the other half yellow flowers.

• Three-fourths of the plants should have red flowers, the other one-fourth yellow flowers.

Juliet and her sisters all have the gene for a widow's peak. However, it is only expressed in Juliet. This means that the gene is recessive and Juliet's genes have a _________ condition.

An allele is said to be dominant when it produces its observable effects:

• only in the heterozygous condition.

• only in the homozygous condition.

• in both the heterozygous and homozygous conditions.

• in neither the heterozygous nor homozygous condition.

Genes can only affect behavior by interacting with the...

(a)  

Pair and Share: What is selective breeding? You may also respond with an example.

How did Tryon address the potential criticism that the behavior of “maze bright” and “maze dull” rats might be due to learning rather than to genes?

• He tested the rats in the maze at an early age, before they had acquired learned behaviors.

• He raised all the rats together, so that the two strains intermingled.

• He demonstrated that the rats in each group were all genetically identical to one another.

• He raised some of the offspring from each strain using mothers from the other strain.

The term _____ refers to the set of genes that the individual inherits, and the term _____ refers to the observable properties of the body and behavioral traits.

• Genotype; phenotype.

• Homozygous; heterozygous.

• Phenotype; genotype.

• Heterozygous; homozygous.

Pair and Share: What regulates genes in epigenetics (hint. DNA code does not change)?