Grade 9 Genetics Assessment 2020

What can you say about the results of the punnett square pictured?

• It is guaranteed that 75% of the offspring from these 2 parent flowers will be purple

• There will always be 1 white flower for every 3 purple flowers

• The probability of an offspring with white flower is 25%

• It is impossible that about half of the offspring will be white

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

NGSS.HS-LS3-3

Scientists refer to an organism that has 2 different alleles for a trait as a ________

• Pure breed

• hybrid

• Dominant phenotype

• Recessive phenotype

The set of observable characteristics of an individual as a result of interaction between their genetic information and the environment is an individual’s ____________

• genotype

• Allele frequency

• genome

• phenotype

When a cell is preparing to make a copy of itself, the DNA is neatly arranged in the form of ____________, otherwise the DNA is part of a disorganized “mess” called _______

• chromosomes…….chromatin

• protein…...cells

• gene…...allele

• chromatin……. chromosomes

Tags

NGSS.HS-LS1-4

In cats, ears that curl backwards is a recessive trait.

Two cats that are both heterozygous for normal ears are crossed. What percentage of the offspring can be expected to have normal ears?

• 0%

• 50%

• 25%

• 75%

In a certain plant, the alleles A, B, and C are dominant to the alleles a, b, and c. A plant with the genotype AABbcc will have the same phenotype as the plant with the genotype __________

• Aabbcc

• aabbcc

• AaBBcc

• AABBCc

In carrots the color is inherited according to incomplete dominance. There are homozygous purple carrots and homozygous orange carrots, but the heterozygous genotype produces a red carrot. What is the expected genotype ratio when a purple carrot is crossed with a red carrot?

The alleles can be represented with the following letters:

P = purple O = orange

• PP : OO

  2 : 2

• PO : OO

  2 : 2

• PP : PO

  2 : 2

• PP : OO : PO

  1 : 2. : 1

In guinea pigs, rough fur is completely dominant to smooth fur. What is the expected phenotype ration when two heterozygous guinea pigs are crossed?

• smooth : rough

  0 : 4

• rough : smooth

  3 : 1

• rough : smooth

  2 : 2

• rough : smooth

  1 : 3

In a particular species of gecko, black eyes are completely dominant to red eyes. When 2 geckos with black eyes are crossed, 40 offspring are produced. 11 have red eyes, and 29 have black eyes.

B = black eyes b = red eyes

What are the genotypes of the parents?

• BB and Bb

• bb and bb

• Bb and Bb

• BB and bb

Hemophilia is a disease carried by a recessive allele on the X-chromosome. Joanne and Phil are thinking about having children (neither of them have hemophilia), but Phil’s father had hemophilia and Joanne’s mother had hemophilia.

What are the chances of Phil and Joanne having a son with hemophilia?

• 0%

• 12.5%

• 75%

• 25%