Open Sci Ed Genetics

In pea plants, the smooth pea gene is dominant over the wrinkly pea gene. A farmer crossed two pea plants and obtained offspring pea plants with wrinkly peas.

Which statement is true about inheritance of the trait by the offspring?

• The offspring inherited two recessive alleles, one from each parent.

• The offspring inherited two dominant alleles, one from each parent.

• The offspring inherited two recessive alleles from the same parent.

• The offspring inherited two dominant alleles from the same parent.

Tags

NGSS.MS-LS3-2

In cattle, the allele for a long-haired coat (L) is dominant over the allele for a short-haired coat (l). What combination of parental alleles will produce all purebred, long-haired offspring?

• ll x ll

• Ll x Ll

• LL x ll

• LL x LL

Tags

NGSS.HS-LS3-1

What is shown by the inheritance of pink flowers?

• The white flower allele is dominant over the red flower allele because it is expressed in more genotypes than the red flower gene.

• The alleles show incomplete dominance because the phenotype for two of the offspring is a blending of both alleles.

• The alleles show codominance because they are both expressed in the genotype of the offspring with the pink flower phenotype.

• The red flower allele is dominant over the white flower allele because it is always written first in the genotypes.

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

A teacher tells her students that the inheritance of flower color in Camellia plants shows codominance. In Camellia plants, both red (R) and white (W) are dominant alleles.

Which Punnett square correctly predicts the possible genotypes for a cross between a homozygous dominant plant with red flowers and a homozygous dominant plant with white flowers?

• 
• 
• 
• 

Tags

NGSS.HS-LS3-1

The Punnett square shows a cross between a curly haired female and a straight haired male. The couple have three children, all have wavy hair.

What phenomenon is shown by the production of wavy hair?

• codominance

• complete dominance

• incomplete dominance

• recessiveness

In humans, hair lines can have a widow's peak (H) or be straight (h). The Punnett square shows a cross between a mom with a widow's peak and a dad with a straight hairline.

Which statement explains why all offspring have a widow's peak?

• All the offspring have the dominant allele.

• All the offspring have the recessive allele.

• Both parents have a dominant allele.

• Both parents have a recessive allele.

The table shows the phenotypes of plants produced from two plants with tall pea plants. The allele for tall plants (T) is dominant over the allele for short plants (t).

Phenotype : Number of Offspring

tall plants : 21

short plants : 6

What can be concluded about the genotypes of the parents?

• Both parents are Tt

• One parent is TT and the other is Tt

• Both parents are tt

• One parent is Tt and the other is tt

Examine the Punnett square that shows the probable offspring of a cross between two humans where R represents can roll tongue and r represents cannot roll tongue.

What would be the genotypes for the parents?

• RR x RR

• rr x rr

• RR x Rr

• Rr x Rr

Tags

NGSS.HS-LS3-1

Which genotype represents a plant with short stems?

• tr

• tt

• TT

• Tt

The Punnett square shows four combinations of alleles for cleft chin (C) and smooth chin (c).

Which genotype should replace the question mark?

• CC

• Cc

• cc

• c