Test 5 Bio 103

Why is only one strand of DNA transcribed into mRNA?

Because transcribing both DNA strands would produce different amino acid sequences

Analysis of mitochondrial DNA from different species of stickleback fish in three lakes disproves the hypothesis of a common ancestor for all three species.

False

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

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

Introns in pre-mRNA:

are spliced out of the message.

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

biogeography

Autosomal monosomy is not seen in live births because:

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

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

Four-legged, land dwelling mammals

Which of the following is a characteristic of uracil?

It has the ability to bond with adenine

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

The four nucleic acid bases combine in three-letter sequences that define different amino acids.

Two species have homologous structures. What can we infer?

The species are related by a common ancestry.

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

Darwin observed that species fo und on ocean islands do not resemble species on islands with similar environment in other parts of the world

True

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

True

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

Turner

What is a cladogram?

a diagram shovwing lines of descent

Evolution is genetic change in that occurs over time

a population

Initiation of transcription requires:

a promoter sequence

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

a ribosome.

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

adaptation

Uracil forms a complementary pair with _____ in RNA and ______ in DNA

adenine; adenine

Ribose differs from deoxyribose by having:

an extra hydroxyl group

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

autosomal recessive

Cri du chat syndrome arises from:

deletion of part of chromosome 5

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

e.XXY karyotype; fertile male

The wobble hypothesis states that:

ecertain tRNA anticodons can pair with more than one codon sequence.

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

evolution by natural selection

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

genes

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

genes

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

heterozygous for albinism

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

heterozygous for albinism

Which of the following is made from DNA?

mRNA, tRNA, and rRNA

Turner syndrome is an example of a _____ condition

monosomic

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

normal meiosis

Huntington's disease is caused by a:

nucleotide triplet repeat

These noncoding sequences located within coding regions of _____ genes are called

only eukaryotic; introns

Translocation occurs when:

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

Polyploidy is the:

presence of multiple sets of chromosomes

Fragile X syndrome:

results in learning, attention, and hyperactivity disabilities in males

RNA is_and contains the nitrogenous basewhich is absent in DNA.

single stranded; uracil

In genomic imprinting:

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

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

the knowledge that all genetic variations lead to genetic disease

Down syndrome is characterized by:

the presence of 47 chromosomes per somatic cell

RNA synthesis is also known as:

transcription.

Nearly half of the pregnancies that end in miscarriage have:

trisomy of chromosome 21

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

64

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

15; father

The normal human karyotype contains ___ total chromosomes, consisting of ___ autosomes and ______ sex chromosomes

23; 22; 1

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

25,000 ; 2 %

The modern synthesis theory of evolution explains Darwin's observations of variation among offspring in terms of amino acids substitutions.

False