BIOL 100 LECTURE EXAM 3

Terms in this set (51)

Liver cells and kidney cells do different tasks because they
contain the same DNA but use different genes.
How is nuclear DNA modified in order for gene expression to occur?
It is separated from histone proteins by acetylation.
What is a chromosome?
a large, tightly bound piece of DNA and protein found in the nucleus of cells
An individual's DNA is
identical in all cells.
What is a genome?
the complete set of genetic material encoded within the DNA of an organism
A mutation in a DNA coding region of a protein can cause
a change in tertiary structure of the protein.

a change in primary structure of the protein.

a change in quaternary structure of the protein.

a change in secondary structure of the protein.

All of the above.
If a trait is not displayed in the phenotype, it is called
recessive.
All of the following are true of alleles, EXCEPT

there may be many different alleles in the population.

when alleles of a gene differ, the organism is said to be homozygous.

for some diseases, if a person has only one disease allele, they may be healthy.

pairs of alleles reside on homologous chromosomes.

they vary in nucleotide sequence.
when alleles of a gene differ, the organism is said to be homozygous.
An organism's _________ determines its __________.
genotype; phenotype
When Mendel self-pollinated plants from the purple-flowered F1 generation, he saw that one out of every four plants in the F2 had white flowers. What reasoning did Mendel use to explain how the white, hidden trait reappeared?
He reasoned that each parent had two elements, one representing purple and one white.

He reasoned that, during gamete formation, the two elements separate randomly.


He reasoned that the recessive or hidden allele only shows up in offspring with two copies of the recessive allele.

He reasoned that two parental elements separate during gamete formation, and each gamete receives only one of the two parental alleles.

All of the answers are correct.
Skin color is controlled by six separate genes, making the inheritance of skin color a good example of
polygenic inheritance.
Mendel observed that crossing a purple-flowered pea plant with a white-flowered pea plant always produced purple-flowered offspring in the F1 generation. Select TWO inferences could he make from this observation?
The purple trait is dominant, and the white trait is recessive.

The two parental traits were not blended in the F1 generation.
Multifactorial inheritance includes what factors in addition to multiple genes interacting?
general health

amount of exercise

environment

diet

All of the above.
What does it mean for a trait to be both polygenic and multifactorial?
Multiple genes each produce aspects of a trait, and environmental factors influence the expression of those genes.
What does it mean for a trait to be both polygenic and multifactorial?
Multiple genes each produce aspects of a trait, and environmental factors influence the expression of those genes.
What is a chromosome?
a large, tightly bound piece of DNA and protein found in the nucleus of cells
Which statement accurately describes how genes, chromosomes, and proteins are related?
A gene on a chromosome encodes a protein.
What is a genotype?
the genetic makeup of an individual
A phenotype is
a physical trait.
What information do genes provide about proteins? Select the TWO answers that are correct.
how much a protein will be expressed

how long a translated protein will be
What is the final product of gene expression?
a protein
Liver cells and kidney cells do different tasks because they
contain the same DNA but use different genes.
What is the significance of gene mutations in terms of protein function and clinical outcome?
A and B.

Analyzing specific mutations allows researchers to study overall gene function.

Changes in gene sequence can alter the shape or function of a protein.

Gene mutations allow researchers to identify deficient proteins and aid in therapeutic intervention, such as in cystic fibrosis.

All of the above.
An individual's genotype predicts an adult height of 6.5 feet, but that individual grows to only 5.5 feet in adulthood. What accounts for the difference in height?
environmental factors
The _____ control(s) the timing of gene expression.
regulatory sequence for a gene
A gene is a section of a(n) __________ molecule.
DNA
What would happen if spindle fibers failed to form during the cell cycle?
The chromosomes of the parent cell would not divide.
Relative to one of your liver cells, one of your skin cells has _____.
the same genome and a different pattern of gene expression
How does interphase relate to mitosis?
Interphase alternates with mitosis.
If every cell contains the entire genome, how do cells specialize?
by turning on a subset of specific genes
Chromosomes are duplicated during
the S phase.
The process of _____ is used to replace damaged or worn-out cells.
cell division
How are proto-oncogenes and tumor suppressor genes different?
Proto-oncogenes promote cell division when a cell is ready, and tumor suppressor genes halt cell division when a DNA sequence needs correction or repair.
What is the result of the mitosis checkpoint being passed before the cell is ready?
improperly aligned chromosomes that are not equally distributed to daughter cells
What is the purpose of cell cycle checkpoints?
to ensure that cell cycle phases proceed only when the cell is ready
Cell cycle checkpoints detect and control
DNA content.

signals that promote cell division.

DNA damage.

proper chromosome alignment.

All of the above.
Select three possible ways mutations can be acquired. Select the THREE answers that are correct.


transcribing DNA incorrectly during protein synthesis

leaving mistakes uncorrected during DNA replication

being exposed to substances that damage DNA

receiving mutations through a vaccination

inheriting mutations from one's parents
leaving mistakes uncorrected during DNA replication

being exposed to substances that damage DNA

inheriting mutations from one's parents
In an otherwise normal cell, what happens if one mistake is made during DNA replication?
A cell cycle checkpoint detects the error and pauses the cell cycle so the error can be corrected.
What is the result of the mitosis checkpoint being passed before the cell is ready?
improperly aligned chromosomes that are not equally distributed to daughter cells
Which phrases accurately describe the role of microtubules in the cell cycle? Select the TWO answers that are correct.

migration of the chromosomes

disassembly of the nuclear membrane

organization of the chromosomes

replication of the chromosomes

separation of the cell cytoplasm
migration of the chromosomes

organization of the chromosomes
Why does wearing sunscreen reduce cancer risk?
Sunscreen can reduce the chance of mutations caused by exposure to UV radiation present in sunlight.
Some cancer chemotherapy blocks the formation of the mitotic spindle during prophase. Why would cancer chemotherapy limit the ability of adult stem cells to perform the normal cell turnover in a tissue?
Cancer chemotherapy blocks mitosis.
Select three possible ways mutations can be acquired. Select the THREE answers that are correct.

transcribing DNA incorrectly during protein synthesis

leaving mistakes uncorrected during DNA replication

being exposed to substances that damage DNA

receiving mutations through a vaccination

inheriting mutations from one's parents
leaving mistakes uncorrected during DNA replication

being exposed to substances that damage DNA

inheriting mutations from one's parents
How are proto-oncogenes and tumor suppressor genes different?
Proto-oncogenes promote cell division when a cell is ready, and tumor suppressor genes halt cell division when a DNA sequence needs correction or repair.
Cell division is usually kept under control by
several checkpoints in the cell cycle and by apoptosis.
A potential cancer-causing gene coding for a protein with cell cycle control responsibilities is a _____, and a gene coding for a protein that stimulates cell division is a _____.
carcinogen; proto-oncogene
What types of genes do all cells have turned on?
genes for basic cell functions
What might be the result of a mutation in one of the proteins responsible for the G1 checkpoint?
The cell would continue to S phase without signals to divide being present.

The cell would divide uncontrollably.

The cell would move through the cell cycle more rapidly than normal.

Nothing; one of the other checkpoints would make up for its absence.

All of the above.
CRISPR is a molecular tool that naturally exists in some types of ___________.
bacteria
CRISPR is made up of
RNA and an enzyme.
CRISPR differs from other methods of genetic engineering because
it can alter a precise location of the genome.
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