Genetics

Multiple Choice
Identify the choice that best completes the statement or answers the question.

____	1.	What happens when a true-breeding plant self-pollinates?
a.	One of its offspring has the same traits as the parent.	
b.	Some of its offspring have the same traits as the parent.	
c.	All of its offspring have the same traits as the parent.	
d.	None of its offspring have the same traits as the parent.	

____	2.	Each parent gives one set of these to the offspring.
a.	genes	c.	phenotypes	
b.	alleles	d.	meiosis	

____	3.	A plant with two dominant or two recessive alleles is said to be
a.	heterozygous.	c.	homozygous.	
b.	cross-pollinating.	d.	true-breeding.	

____	4.	Which one of the following statements is NOT true?
a.	One gene can influence many traits.	
b.	Several genes can influence a single trait.	
c.	The environment can have an influence on traits.	
d.	Genes are the only influence on traits.	

____	5.	How is asexual reproduction beneficial?
a.	Organisms reproduce very slowly.	
b.	Organisms reproduce with many genetic variations.	
c.	Organisms do not need other organisms to reproduce.	
d.	Organisms need other organisms to reproduce.	

____	6.	Asexual reproduction relates to humans in that
a.	none of our body cells reproduce this way.	
b.	many body cells reproduce this way.	
c.	the parent cells do not divide.	
d.	meiosis occurs.	

____	7.	How are sex cells different from other human cells?
a.	Sex cells have more chromosomes.	
b.	Sex cells have half as many chromosomes.	
c.	Sex cells are larger.	
d.	Sex cells have no chromosomes.	

____	8.	What is an advantage of sexual reproduction?
a.	It allows for genetic variations.	
b.	It does not allow for genetic variations.	
c.	Organisms do not need other organisms to reproduce.	
d.	Organisms can reproduce very quickly.	

____	9.	What occurs during meiosis?
a.	Chromosomes are copied once, and the nucleus divides twice.	
b.	The parent cell divides and makes two exact copies.	
c.	Cells with twice the usual number of chromosomes are produced.	
d.	Chromosomes are copied twice, and the nucleus divides once.	

____	10.	The process of mitosis occurs in
a.	selective breeding.	c.	asexual reproduction.	
b.	homologous breeding.	d.	sexual reproduction.	

____	11.	What are homologous chromosomes?
a.	chromosomes that carry the same set of genes	
b.	chromosomes that carry different sets of genes	
c.	chromosomes that are small	
d.	chromosomes that are large	

____	12.	The one thing that Gregor Mendel realized could explain the results of his experiments was that
a.	the traits were appearing at random.	
b.	the male traits were always the dominant ones.	
c.	each trait had two sets of instructions, one from each parent.	
d.	his important research would open the door to modern genetics.	

____	13.	What carries the genes that determine sex?
a.	homologous chromosomes	c.	sex chromosomes	
b.	pedigree	d.	phenotype	

____	14.	Instructions for an inherited trait are called
a.	alleles.	c.	albinism.	
b.	phenotype.	d.	genes.	

____	15.	The different forms of a gene that decide a characteristic are known as
a.	alleles.	c.	albinism.	
b.	phenotypes.	d.	genes.	

____	16.	What did Mendel discover about recessive traits?
a.	Recessive traits reappear in the second generation.	
b.	Recessive traits disappear altogether.	
c.	Recessive traits never appear in the second generation.	
d.	Recessive traits become dominant.	

____	17.	Which one of the following is the name for the way cells divide in asexual reproduction?
a.	twins	c.	meiosis	
b.	mitosis	d.	homologous	

____	18.	Which one of the following can have an influence on traits?
a.	environment	c.	pollen	
b.	phenotype	d.	albinism	

____	19.	What are chromosomes that carry the same sets of genes?
a.	twin chromosomes	c.	ordinary chromosomes	
b.	homologous chromosomes	d.	asexual chromosomes	

____	20.	Males are more likely to have sex-linked disorders because they have
a.	only one X chromosome.	c.	two X chromosomes.	
b.	two Y chromosomes.	d.	one X and two Y chromosomes.	

____	21.	When a plant fertilizes itself, it is called a(n)
a.	allele plant.	c.	self-pollinating plant.	
b.	true-breeding plant.	d.	cross-pollinating plant.	

____	22.	When there is incomplete dominance,
a.	one allele has more influence than the others.	
b.	blending occurs	
c.	the alleles have no influence.	
d.	there are no alleles present.	

____	23.	What kind of plant produces offspring with the same traits as the parent?
a.	self-pollinating	c.	true-breeding	
b.	cross-pollinating	d.	nonbreeding	

____	24.	What do you call one set of instructions for an inherited trait?
a.	alleles	c.	albinism	
b.	phenotype	d.	genes	

____	25.	Two forms of a gene, one from each parent, are called
a.	alleles.	c.	albinism.	
b.	phenotypes.	d.	genes.	

____	26.	Offspring that are different from both parents are produced by
a.	asexual reproduction.	c.	sexual reproduction.	
b.	something going wrong.	d.	mitosis.	

____	27.	What is heredity?
a.	traits passing from offspring to parents	c.	plants that are cross-pollinated	
b.	traits passing from parents to offspring	d.	the ratio of dominant to recessive traits	

____	28.	What is a plant that has two dominant genes or two recessive genes called?
a.	organism	c.	homozygous	
b.	genotype	d.	heterozygous	

____	29.	What is Mendel’s ratio for dominant to recessive traits?
a.	1 to 1	c.	3 to 1	
b.	2 to 1	d.	4 to 1	

____	30.	What is a phenotype?
a.	the way an organism feels	c.	a dominant gene	
b.	a group of 5 alleles	d.	the way an organism looks	

____	31.	What is it called when cells are copied with half the number of chromosomes?
a.	sex cells	c.	a nucleus	
b.	meiosis	d.	mitosis	

____	32.	What letters represent the four bases in DNA?
a.	A, B, C, D	c.	A, T, G, C	
b.	W, X, Y, Z	d.	E, Y, A, O	

____	33.	Using X-ray diffraction, what did Rosalind Franklin show the shape of DNA to be?
a.	a circle	c.	a square	
b.	a spiral	d.	a line	

____	34.	Watson and Crick built a DNA model like a
a.	long, twisted ladder.	c.	straight line.	
b.	piece of twine.	d.	pyramid.	

____	35.	The “rungs” of the DNA ladder are
a.	a pair of bases.	c.	a pair of phosphates.	
b.	a pair of sugars.	d.	a set of proteins.	

____	36.	To be copied, a DNA molecule splits
a.	across the top.	c.	along the sides.	
b.	down the middle.	d.	along the phosphates.	

____	37.	A string of nucleotides that has instructions for a certain trait is a
a.	cell.	c.	gene.	
b.	ribonucleic acid.	d.	chromosome.	

____	38.	Which best expresses the relationship between genes and DNA?
a.	genes carry DNA	c.	both carry chromosomes	
b.	DNA carries genes	d.	they are unrelated	

____	39.	What did Watson and Crick’s model of DNA look like?
a.	a ball	c.	links in a chain	
b.	a straight line	d.	a long, twisted ladder	

____	40.	A string of nucleotides that has information for making one trait is
a.	a protein.	c.	an amino acid.	
b.	a gene.	d.	a cell.	

____	41.	Which of the following is a disease that is caused by a gene mutation and that affects red blood cells?
a.	diabetes	c.	sickle cell disease	
b.	lung cancer	d.	Parkinson’s disease	

____	42.	Using DNA to identify who committed a crime is
a.	genetic engineering.	c.	genetic disease.	
b.	DNA fingerprinting.	d.	DNA cloning.	

____	43.	Some genetic disorders, such as sickle cell anemia, are due to
a.	a ribosome.	c.	a DNA fingerprint.	
b.	a mutation.	d.	genetic engineering.	

____	44.	The complementary strand to the DNA sequence TAGTCA is
a.	ATGAGT.	c.	GTAGAT.	
b.	GACAGT.	d.	ATCAGT.	

____	45.	What determines how tall you grow and whether your hair is curly or straight?
a.	a chromatid	c.	proteins	
b.	RNA	d.	ultraviolet radiation	

____	46.	What does each gene have instructions for making?
a.	a cell	c.	a protein	
b.	a ribosome	d.	RNA	

____	47.	If a scientist was trying to find out if a certain person had Benjamin Franklin as an ancestor, he/she would most likely use
a.	genetic engineering.	c.	substitution.	
b.	replication.	d.	DNA fingerprinting.	

____	48.	The substitution of the DNA sequence GAA to GTA, can result in the genetic disorder sickle cell disease. How does sickle cell disease affect the shape and function of red blood cells?
a.	they become sickle-shaped and carry less oxygen	
b.	they become sphere-shaped and carry more oxygen	
c.	they become sphere-shaped and carry less oxygen	
d.	they become sickle-shaped and carry more oxygen