Genotype and Phenotype Quiz

Q1

Genotype is the observable features of an organism True/False

Answer

False

Remember in our lesson on genotype and phenotype, we discovered that the genotype is what we have within our DNA, and is not observable or physical. Rather, the physical features we see like skin and hair color are what we describe as phenotype. Thus, the statement is false. The genotype is the non-observable information contained in our DNA, and which dictates the observable features of an organism.

Q2

Phenotype is the non-observable information encoded in the DNA. True/False

Answer

False

The non-observable information or genetic information is what genotype. Phenotype is the observable features coded by our genome.

Q3

The formation of protein begins with the transcription of DNA to messenger RNA. True/False

Answer

True

The statement is true because the whole process begins inside the nucleus by the formation of messenger RNA. This messenger RNA is then able to leave the nucleus and gets into the cytoplasm, specifically into the ribosomes, an organelle that specializes in the synthesis of proteins. At this location, transcription takes place with the help of various enzymes and ribosomal subunits.

Q4

Translation takes in the nucleus True/False

Answer

False

Transcription makes RNA copy of the gene, a process that is performed by the RNA polymerase enzyme. Translation forms sequence of amino acids using the RNA strand. Transcription takes place in the nucleus while translation takes place in the ribosome.

Summary

Transfer RNA transfers amino acid during protein synthesis in the ribosome. Ribosomal RNA forms part of the ribosome that reads through the RNA strand. The translation is a process of converting mRNA to protein. The three-nucleotide sequence on the mRNA is codon while the tRNA molecule complementary to this sequence is known as an anticodon. The non-coding regions of a gene are introns while the coding regions are the exons.

The promoter is a sequence on the genome which indicates where transcription begins. A change in the sequence of DNA that has an impact on genetic information is called a mutation. If the mutation affects only one nucleotide, it is described as point mutation, and if the reading frame of the gene is affected by either inserting or deleting nucleotide(s), this is described as frameshift mutation.

Revision

Allele
A variation of a gene.

Backcross
A cross between F1 individuals and the pure breeding recessive parent.

Codominance
The quality of two heterozygous alleles that are fully expressed in the phenotype.

Complete Dominance
The phenotype that will be expressed in a heterozygous individual.

Dihybrid Cross
A cross between two individuals that are heterozygous at two loci.

Dominant Phenotype
The characteristic that will be fully expressed in a heterozygous individual.

F1 Generation
The offspring resulting from the first cross of parents.

F2 Generation
The offspring of a cross of parents selected from the F1 generation.

Genotype
The particular allele combination of an individual.

Hemizygote
An organism with only one pair of alleles transmitting a particular character.

Heterozygote
A diploid individual with different alleles at a particular genetic locus.

Homozygote
A diploid individual with two identical alleles at a particular genetic locus.

Incomplete Dominance
The condition where both alleles of a gene are expressed in the phenotype.

Monohybrid Cross
A cross between organisms that involves only a single gene, usually with two different alleles.

Mutant
An organism that carries an altered or changed gene.

Phenotype
The expressed characteristic or trait of an organism that results from the genotype.

Principle of Independent Assortment
Mendel’s second law of heredity, which states that in a cross concerning two traits, each controlled by one gene with two alleles, each allele is segregated independently of other alleles into the gametes.

Principle of Segregation
Mendel’s first law of heredity that states that each allele segregates into a different gamete during sex cell formation so that each gamete receives one copy of each allele for one gene.

Pure-Breeding
Another term for homozygous where an organism has two identical alleles at a particular locus.

Recessive Phenotype
The phenotype that will only be expressed when both alleles at a particular locus are recessive.

Recessive Lethal
A mutation that is a dangerous to the homozygous organism.

Regulatory Gene
Genes that function to regulate the expressions of other genes.

Testcross
A cross between an unknown heterozygous individual and their homozygous recessive parent.

Trait
A characteristic or feature of an organism.

Wild-type
The genotypes and phenotypes that are most commonly observed in the natural populations of the species.