Question

1. which of the following correctly describes the structure of dna?

a. triple - stranded helix
b. double - stranded helix
c. coiled structure without nucleotides
d. single - stranded helix

1. in mendelian genetics, what happens during the law of segregation?

a. traits from different parents assort independently
b. parents pass all of their traits to their offspring
c. different traits do not depend on each other
d. parents pass half of their traits to their offspring; the child will receive one allele from their father and one from their mother for a given trait

1. how does the sequence of nitrogenous bases in dna affect an organism?

a. it controls the organisms environment
b. it determines the organisms age
c. it dictates the organisms habitat
d. it influences the organisms characteristics

1. what term refers to the observable, physical traits resulting from the interaction between an organisms genotype and its environment?

a. genotype
b. recessiveness
c. phenotype
d. dominance

1. what does a homozygous genotype indicate?

a. a dominant trait being expressed
b. a recessive trait being expressed
c. two identical alleles for a gene
d. two different alleles for a gene

1. which of the following represents a dominant allele?

a. uppercase letter
b. letter with an exclamation point
c. lowercase letter
d. letter that is always hidden by the recessive allele

1. when crossing two homozygous individuals for a dominant trait (bb x bb), what is the chance of their offspring will be heterozygous?

a. 0%
b. 25%
c. 50%

Explanation:

1. DNA has a double - stranded helix structure. This is a well - known fact in molecular biology.
2. The Law of Segregation in Mendelian genetics states that parents pass half of their traits to their offspring; the child will receive one allele from their father and one from their mother for a given trait.
3. The sequence of nitrogenous bases in DNA influences the organism's characteristics as it codes for proteins and other cellular functions.
4. The observable, physical traits resulting from the interaction between an organism's genotype and its environment are called the phenotype.
5. A homozygous genotype indicates two identical alleles for a gene.
6. A dominant allele is typically represented by an uppercase letter.
7. When crossing two homozygous individuals for a dominant trait (AA x AA), all offspring will be homozygous, so the chance of heterozygous offspring is 0%.

Answer:

1. b. Double - stranded helix
2. d. Parents pass half of their traits to their offspring; the child will receive one allele from their father and one from their mother for a given trait.
3. d. It influences the organism's characteristics
4. c. Phenotype
5. c. Two identical alleles for a gene
6. a. Uppercase letter
7. a. 0%