Staar Biology Genetics

The butterflies represent the offspring in the F1 generation. What statement is best supported by the phenotypes of these offspring?

• the  F1 generation is composed only of males
• two of the offspring in the F1 generation will not be able to reproduce
• the F1 generation is the result of a dihybrid cross
• two of the offspring in the F1 generation will experience spontaneous mutation

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NGSS.HS-LS3-1

NGSS.HS-LS3-2

Frizzled feathers are dominant over straight feathers. Two chickens with straight feathers are crossed. What percentage of the offspring will have frizzled feathers?

• 0%
• 25%
• 50%
• 100%

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NGSS.HS-LS3-1

NGSS.HS-LS3-2

NGSS.HS-LS3-3

Tomato plants usually have hairy stems. Hairless stems are present in tomato plants that are homozygous recessive for this trait. What is the expected outcome of crossing two tomato plants that are heterozygous for hairy stems?

• 75: hairy stems; 25% hairless stems
• 100% hairy stems
• 100% hairless stems
• 50% hairy stems; 50% hairless stems

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

Black fur (B) is dominant over brown fur (b) and short fur (F) is dominant over long fur (f). What percentage of the offspring from BbFf x bbff would be expected to be heterozygous for both traits?

• 0%
• 25%
• 50%
• 100%

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NGSS.HS-LS3-2

NGSS.HS-LS3-3

Plants with the genotype TTYy are crossed with pea plants with the genotype Ttyy. What percentage of the offspring will be expected to have the TTYy combination?

• 25%
• 40%
• 50%
• 75%

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NGSS.HS-LS3-2

NGSS.HS-LS3-3

Normal fruit flies have brownish-yellow bodies which is the dominant trait. A homozygous normal fruit fly (e+ e+) is crossed with a homozygous ebony fruit fly (ee). What is the predicted outcome of this genetic cross?

• all the offspring will have ebony bodies
• 75% will have brownish-yellow bodies and 25% will have ebony bodies
• all the offspring will have brownish-yellow bodies
• 75% will have ebony bodies and 25% will have brownish-yellow bodies

Tags

NGSS.HS-LS3-1