Bio Test 5

Overproduction, variation, limits on population growth, and differential reproductive success are all components of:

d. Evolution by natural selection

Two species have homologous structures. What can we infer?

d. The species are related by a common ancestry.

Cri du chat syndrome arises from:

d. nondisjunction

Polyploidy is the:

d. presence of multiple sets of chromosomes

In genomic imprinting:

d. the expression of a gene in the progeny depends upon which parent the gene is inherited from.

The molecule that connects a growing polypeptide chain and mRNA is called:

e. a ribosome.

The wobble hypothesis states that:

e. certain tRNA anticodons can pair with more than one codon sequence.

The discovery of fossils of whale intermediates suggest that whales evolved from:

e. four-legged, land dwelling mammals

Which of the following is made from DNA?

e. mRNA, tRNA, and rRNA

RNA synthesis is also known as:

e. transcription

The human genome contains about ____ genes, which comprises about _____ of the genome.

20,000 to 25,000; 1%

Initiation of transcription requires:

C. an RNA primer

Medicine must respond with new drugs and vaccinations to the slow evolution of disease-causing organisms such as bacteria and viruses. TRUE or FALSE

False

The genotypes of the normal females in the second generation in accompanying figure are:

Heterozygous for albinism

The total number of different three-base combinations of the four nucleic acid bases is:

d. 64

Acquired variations that are favorable to the survival of an organism tend to be present in greater frequency in the next generation of those organisms. TRUE OR FALSE

TRUE

The accumulation of genetic changes in vertebrates that modified the basic body plan laid out in fish development illustrates evolutionary development from a common ancestor. TRUE OR FALSE

TRUE

A karyotype reveals that an individual is XYY. Based on your knowledge of human genetics, you correctly conclude that this individual has ____, and is a phenotypically _____.

XXY karyotype; fertile male

Refer to the accompanying figure. Based on the phenotypes of the third generation, the genotype of the father in the second generation must be:

a. Heterozygous for albinism

Which of the following is a characteristic of uracil?

a. It has the ability to bond with adenine.

Persons having an XO karyotype are sterile females. They have ____ syndrome.

a. Turner

Which is the study of past and present distributions of organisms on earth?

a. biogeography

Turner syndrome is an example of a __________ condition.

a. monosomic

.The sperm in the figure below were most likely produced by:

a. nondisjunction

These noncoding sequences located within coding regions of ____ genes are called ____.

a. only eukaryotic; introns

Translocation occurs when:

a. part of a chromosome breaks off and attaches to a nonhomologous chromosome

Huntington's disease is caused by a:

a. rare recessive allele

What was revealed with the completion of the Human Genome Project?

a. the sequence of the entire human genome

Down syndrome is characterized by:

a. trisomy of chromosome 21

An individual who inherits the specific chromosome ____ deletion from his/her ____ will most likely have Prader-Willi syndrome rather than Angelman syndrome.

b. 15; father

Why is only one strand of DNA transcribed into mRNA?

b. Because transcribing both DNA strands would produce different amino acid sequences

Evolution is genetic change in ____ that occurs over time.

b. Population

How is the four-letter language of nucleic acids converted into the 20-word language of amino acids?

b. The 4 nucleic acid bases combine in 3-letter sequences that define different amino acids.

What is a cladogram?

b. a diagram showing lines of descent

Uracil forms a complementary pair with ____ in RNA and ____ in DNA.

b. adenine; thymine

Introns in pre-mRNA:

b. are spliced out of the message.

The genetic code is sometimes called "universal," meaning that all organisms share the same:

b. coding mechanism

Scientific evidence in the field of developmental biology overwhelmingly demonstrates that development in different animals is controlled by the same kinds of:

b. genes

The normal human karyotype contains ____ total chromosomes, consisting of ____ autosomes and ____ sex chromosomes.

c. 46; 22, 2

How does the first nucleotide at the 5′ end of a new mRNA chain differ from the other nucleotides in the chain?

c. The first nucleotide retains its triphosphate group, while the others do not.

The inheritance pattern demonstrated by the pedigree in accompanying figure is:

c. X-linked recessive

Ribose differs from deoxyribose by having:

c. an extra hydroxyl group

.Autosomal monosomy is not seen in live births because:

c. its effects are so lethal as to cause spontaneous abortion early in pregnancy.

Nearly half of the pregnancies that end in miscarriage have:

c. major chromosomal abnormalities

Which process provides the genetic variability that natural selection acts on during evolution?

c. mutation

RNA is ____ and contains the nitrogenous base ____, which is absent in DNA.

c. single stranded; uracil