Question

21.
Choose the best answer.

This refers to the structure formed by double-stranded molecules of nucleic acids such as DNA and RNA.

codon

helix

double helix

gamete
22.
Choose the best answer.

A ___ is part of a bacterial cell.

mutant

clone

plasmid

bacterium
23.
Choose the best answer.

A hereditary unit consisting of a sequence of DNA that occupies a specific location on a chromosome and determines a particular characteristic is a(n) __________.

genotype

gene

trait

allele
24.
Choose the best answer.

The allele in which only one of its type needs to be present for the trait to be expressed is called ___.

homozygous

recessive allele

dominant allele

genotype
25.
Fill in the blank.

Use the Punnet Square below for this cross. Answer the following questions:


C c
C CC Cc
c Cc cc


Cc = recessive cystic fibrosis disease
cc = cystic fibrosis disease
1. What is the probability that they will have a child with cystic fibrosis?



2. Identify the genotypes that will express the cystic fibrosis disease.


26.
Choose the best answer.

A gene that alters or influences the expression function of another gene is a ___________.

recessive

modifying gene

dominant

regulating gene
27.
Choose the best answer.

A relationship among alleles where both alleles contribute to the phenotype of the heterozygote is __________.

polyploidy

triploidy

pleiotropy

codominance
28.
Select 2 that apply.

Nucleotides form base pairs for DNA, namely: _____ and _____.


adenine (A) & thymine (T)

cytosine (C) & thymine (T)

cytosine (C) & guanine (G)

adenine (A) & cytosine (C)

adenine (A) & guanine (G)
29.
Choose the best answer.

the allele that requires two of its type on a gene in order to show up in the phenotype is called ____.

dominant allele

genotype

homozygous

recessive allele
30.
Choose the best answer.

Who is regarded as the founder of modern genetics?

Aristotle

Charles Darwin

Gregor Mendel

Socrates

Answer 1

21. double helix

22. plasmid

23. gene

24. dominant allele

25.
1) 25% (1 out of 4)
2) cc (homozygous recessive expresses cystic fibrosis; Cc are carriers)

26. modifying gene

27. codominance

28. adenine (A) & thymine (T); cytosine (C) & guanine (G)

29. recessive allele

30. Gregor Mendel