Honors Biology Exam Review

Each pea-plant gamete has how many alleles for the height gene

1

The different forms of a gene are called

alleles

Gregor Mendel removed the male parts from the flowers of some plants in order to

Control crosses between plants

If a pea plant has a recessive allele for green peas, it will produce

Green peas if it does not also have a dominant allele for yellow peas

When Gregor Mendel crossed a tall plant with a short plant, the F1 plants inherited

One allele form each parent

If a pea plant’s alleles for height are tt, what is true of its parents?

Both parents contributed a recessive allele

When Gregor Mendel crossed true-breeding tall plants with true-breeding short plants, why was it impossible to observe segregation?

Alleles in the F1 must be Tt to have height variety in the F2

A tall plant (TT) is crossed with a short plant (tt). If the tall F1 pea plants are allowed to self-pollinate,

the offspring can be tall or short

In the P generation, a tall plant was crossed with a short plant. Short plants reappeared in the F2 generation because

the alleles for both heights segregated when the F1 plants made gametes

When you flip a coin, what is the probability that it will come up tails?

1/2

The principles of probability can be used to

predict the traits of the offspring of genetic crosses

A heterozygous tall pea plant is crossed with a short plant. The probability that an F1 plant will be tall is

50%

Organisms that have two indentical alleles for a particular trait are said to be

Homozygous

What principle states that during gamete formation genes for different traits separate without influencing each other’s inheritance?

principle of independent assortment

Gregor Mendel’s principles of genetics apply to

all organisms

Why did Thomas Hunt Morgan use fruit flies in his studies?

Fruit flies produce a large number of offspring

A male and female bison that are both heterozygous for normal skin pigmentation (Aa) produce an albino offspring (aa). Which of Mendel’s principals explains why the offspring is albino?

dominance and segregation

Roan cattle show codominance for the color of their hair. There are alleles for red hair and white hair. What would you expect a heterozygous roan bull to look like if the trait showed incomplete dominance instead?

It would be pink

A breed of chicken shows codominance for feather color. One allele codes for black feathers, another codes for white feathers. The feathers of heterozygous chickens of this breed will be

speckled

Situations in which one allele for a gene is not completely dominant over another allele for that gene are called

incomplete dominance

In rabbits, there are four different versions of the gene for coat color. What pattern of inheritance is this?

multiple alleles

Variation in human skin color is an example of

Polygenic traits

What determines the color of western white butterflies?

Temperature and genes

The Arctic fox is blue-gray in the summer and white in the winter. What most likely influences this change?

genes and the environment

The number of chromosomes in a gamete is represented by the symbol

N

If an organim’s diploid number is 12, its haploid number is

6

Gametes are produced by the process of

Meiosis

Which bacteria killed the mice in Griffith’s transformation experiment?

live, harmless bacteria and heat-killed, harmful bacteria

Griffith called the process he observed transformation because

the harmless bacteria had been transformed

What did Avery conclude caused transformation?

DNA was the transforming factor

What happened when Griffith injected mice with the harmless, R-strain bacteria alone?

The mouse lived

What would have happened if Avery had added an enzyme that digested all the nucleic acids to the mixture of heat-killed bacteria, added the mixture to harmless bacteria, and injected the mixture into mice?

The harmless bacteria would not have been transformed, and the mice would have lived

What property of DNA does bacterial transformation illustrate?

Bacterial DNA can move into another bacteria and function

Griffith’s experiments advanced the study of genetics by proving that

there is a chemical that contains genetic information that can be passed from one organism to another

What is inside a bacteriophage?

nucleic acid

What do bacteriophages infect?

bacteria

Why did Hershey and Chase label the viral DNA with radioactive phosphorus and not radioactive sulfur?

DNA contains phosphorus and no sulfur

What stores information in a cell?

DNA

What happens when a piece of DNA is missing?

Genetic information is lost

In what way is DNA like a book?

DNA has stored information, that can be copied and passed on

In which cells in the accurate transmission of information most important?

Sex cells

Which of the following is a nucleotide found in DNA?

deoxyribose + phosphate group + cytosine

What structural problem prevents adenine of pairing with guanine?

The bases are both long

DNA makes a good molecule for storing information because

its bases can be joined together in any order, like the letters of the alphabet can be strung to from different words

What was Rosalind Franklin’s contribution to our understanding of the structure of DNA?

She purified large amounts of DNA, stretched the fibers so the strands were parallel, and used X-ray beam to produce an image of the molecule

Rosalind Franklin contributed to the understanding of DNA by

producing images of DNA molecules using X-rays

What was Chargaff’s contribution to the study of DNA?

Chargaff showed that adenine and thymine were found in equal percentages in DNA , but he did not know this was because of base-pairing

Which scientist(s) figured out that the shape of a DNA molecule in a double helix?

Watson and Crick

In the Hershey-Chase experiment, what happened to the bacteria that had been affected by viruses that had radioactive DNA, and to the bacteria that had been infected with viruses that had been marked with radioactive proteins?

The bacteria infected with viruses that had radioactive DNA had become radioactive. The bacteria that had been infected with viruses marked with radioactive proteins were not radioactive

What scientist made X-ray diffraction photos of DNA?

Franklin

What is the chronological order of the important discoveries in the structure of DNA?

Chargaff’s ratios of nucleotides>Franklin makes an X-ray diffraction photo of DNA>Watson and Crick identify the double helix

what forms a base pairs with thymine

Adenine

What did Rosalind Franklin contribute to the effort to identify the structure of DNA?

X-ray diffraction photos of the DNA molecule

Watson and Crick discovered the two strands in DNA

run in opposite directions

DNA replication results in two DNA molecules,

each with one new strand and one original strand

During DNA replication, a DNA strand that has the base CTAGGT produces a strand with the bases

GATCCA

What enzyme works to add DNA to ends of chromosomes in rapidly divining cells such as those found in an embryo, to prevent genes from being lost during replication?

telomerase

RNA contains the sugar

ribose

Unlike DNA, RNA contains

uracil

Which of the following are found in both DNA and RNA?

phosphate groups, guanine, cytosine

Which type of RNA brings the information in the genetic code from the nucleus to other parts of the cell?

mRNA

What is true about transcription?

RNA polymerase can make many molecules of RNA from a single DNA sequence

Which is true of eukaryotic DNA

Introns are sequences of DNA

Which molecules are involved in protein synthesis?

messenger RNA, ribosomal RNA, transfer RNA

From which molecules are mRNA molecules transcribed?

DNA

What is produced during transcription?

RNA molecule structure

How many nucleotides are needed to specify three amino acids?

9

There are 64 codons and 20 amino acids. Which of the following is true?

Several different codons can specify the same amino acid

A promoter is a

binding site for RNA polymerase

What happens during translation?

The cell uses a messenger RNA code to make proteins

During translation, the type of amino acid that is added to the growing polypeptide depends

A protein is being assembled when

RNA is being translated

Genes contain instructions for assembling

proteins

what is the correct sequence of the transfer of information in most organisms

DNA to RNA to protein

A mutation that involves one of a few nucleotides is called

a point mutation

Which of the following is a chromosomal mutation?

inversion

When a chromosome undergoes a deletion mutation, information is

lost

Most mutations

have no effect on an organism

What are some characteristics of polyploidy plants?

They tend to be bigger and stronger than diploid plants

What is found in both DNA and RNA?

phosphate groups, guanine, cytosine

Human females produce egg cells that have

one X chromosome

What percentage of human sperm cells carry an X chromosome?

50%

A human female inherits

two copies of every gene located on the X chromosome

How many chromosomes are shown in a normal human karyotype?

46

What is the probability of the coupe labeled 2 of having a child with a white forelock?

75%

Which of the following diseases and conditions does not appear until late in a person’s life?

Huntington disease

Sickle cell disease is caused by a

change in one allele

People who are heterozygous for sickle cell disease are generally healthy because they

have some normal hemoglobin in their red blood cells

The Human Genome Project

sequence the DNA of every human gene

Darwin noticed that many organisms seemed well suited to

surviving in the environments in which they lived

On the Galápagos Islands, Charles Darwin observed

species similar to mainland South American species

James Hutton’s and Charles Lyell’s work suggests that

Earth is several million years old

In the 1800s, Charles Lyell emphasized that

past geological events must be explained in terms of processes observable today

One scientist who attempted to explain how rock formations, such as rock layers, form and change over time was

James Hutton

Hutton’s and Lyell’s work was important to Darwin because these scientists

suggested the Earth was old enough for evolution to have occurred

Jean-Bapiste Lamarck proposed that organisms

have an innate tendency toward complexity and perfection

When farmers select animals or plants to use for breeding, they look for

natural variations that are present in a species

According to Darwin’s theory of natural selection, individuals who survive are the ones best adapted for their environment. Their survival is due to the

possession of inherited adaptations that maximize fitness

The hypothesis that all species are descended from common ancestors was proposed by

Darwin

Biogeography is the study of

where species and their ancestors live