Genetics Basics
A gene is a specific segment of DNA. What is the primary role of a gene in an organism?
A. To store energy
B. To code for a specific trait
C. To control cell movement
D. To produce oxygen
B. To code for a specific trait
When both a dominant and recessive allele are present, which trait will be expressed?
A. Recessive
B. Dominant
C. Both equally
D. Neither
B. Dominant
What does a Punnett square help scientists predict?
A. The number of parents
B. All possible offspring outcomes
C. The environment of offspring
D. Only dominant traits
B. All possible outcomes
A cross between BB and bb results in what percentage of offspring showing dominant traits?
A. 25%
B. 50%
C. 75%
D. 100%
D. 100%
Which type of reproduction produces genetically identical offspring.
A. Asexual
B. Sexual
C. Both
D. Neither
A. Asexual
A scientist observes an organism with genotype AA. How would this genotype be classified?
A. Heterozygous
B. Homozygous dominant
C. Homozygous recessive
D. Incomplete dominant
B. Homozygous Dominant
Two parents have brown eyes, but their child has green eyes. What is the most likely explanation?
A. A mutation occurred
B. The child inherited two dominant alleles
C. Each parent contributed a recessive allele
D. Eye color is not genetic
C. Each parent contributed a recessive allele.
A cross between TT and tt is performed. What will be the genotype of all offspring?
A. TT
B. tt
C. Tt
D. Mixed genotypes
C. Tt
A cross between Rr and Rr results in what percentage of offspring showing the dominant phenotype?
A. 25%
B. 50%
C. 75%
D. 100%
C. 75%
Which type of reproduction produces the greatest genetic diversity?
A. Both equally
B. Neither
C. Asexual
D. Sexual
D. Sexual
A plant has the genotype Rr. What does this indicate about the plant?
A. It has two dominant alleles
B. It has two recessive alleles
C. It has one dominant and one recessive allele
D. It has no alleles
C. It has one dominant and one recessive allele
A plant with genotype Yy produces yellow seeds, even though it carries a green allele. What does this indicate?
A. Green is dominant
B. Yellow is recessive
C. Yellow is dominant
D. Both alleles are equally expressed
C. Yellow is dominant
A cross between Tt and tt is performed. What percentage of offspring will be tall?
A. 25%
B. 50%
C. 75%
D. 100%
B. 50%
Two heterozygous long-haired cats are crossed. What percentage of offspring will have long hair?
A. 25%
B. 50%
C. 75%
D. 100%
C. 75%
Why do siblings from the same parents often look different?
A. They receive DNA from only one parent
B. They are clones
C. They inherit different combinations of genes
D. They mutate randomly.
C. They inherit different combinations of genes.
If D represents a dominant allele, which correctly represents the recessive allele?
A. D
B. DD
C. d
D. Dd
C. d
Two organisms have genotypes BB and Bb. How do their phenotypes compare?
A. They will be different
B. They will be the same
C. One will not show a trait
D. Both will show recessive traits
B. They will be the same
Rabbits can have long ears or short ears. Long ears are dominant over short ears. If two heterozygous long ear rabbits breed, what is the probability they will have homozygous recessive offspring?
A. 25%
B. 50%
C. 75%
D. 100%
A. 25%
A genetic cross results in 75% dominant and 25% recessive offspring. What are the most likely genotypes of the parents?
A. AA x aa
B. Aa x Aa
C. AA x Aa
D. Aa x aa
B. Aa x Aa
In sexual reproduction, how many parents contribute genetic material to the offspring?
A. One
B. Two
C. Three
D. Four
B. Two
An organism has two different alleles for a trait. What term best describes this?
A. Homozygous
B. Dominant
C. Recessive
D. Heterozygous
D. Heterozygous
Two brothers both have brown eyes. One has genotype BB and the other Bb. What is true?
A. They have different phenotypes and genotypes
B. They have the same phenotype but different genotypes
C. They have the same genotype but different phenotypes
D. They are genetically identical
B. They have the same phenotype but different genotypes.
In pea plants, purple flowers (P) is dominant to white flowers(p). Two plants are crossed. Among the offsprings, 50% have purple flowers and 50% have white flowers. What are the most likely genotypes of the parents?
A. PP and pp
B. Pp and PP
C. Pp and pp
D. pp and pp
C. Pp and pp
A cross between TT x Tt is performed. What percentage of offspring will be TT?
A. 25%
B. 50%
C. 75%
D. 100%
B. 50%
A group of kittens is born from two parent cats. Even though they have the same parents, the kittens show differences in traits such as fur color, patterns, and eye color. Based on your understanding of genetics and reproduction, what is the best explanation for these differences?
A. Each kitten receied genetic material from only one parent.
B. The kittens were produced through asexual reproduction.
C. Each kitten inherited a different combination of genetic material during sexual reproduction.
D. All of the kittens developed from identical genetic material.
C. Each kitten inherited a different combination of genetic material during sexual reproduction.