bio1010 test 2 gayyyy

The pancreatic cancer cell karyotype shown was most likely a somatic/germ line cell and the abnormal chromosome distribution most likely occurred during mitosis/meiosis. Choose the correct answer for the two slashed words.

somatic & mitosis

How many cells are in an average human?

100 trillion

What is the word for the two halves of a chromosome?

chromatid(s)

What is the center point of the chromosome called?

Centromere

What holds chromatids together?

cohesins

What are cohesins?

Protiens (that hold chromatids together)

What occurs during the interphase?

Chromosome duplication and cohesion, (and) centromere duplication

What occurs during the prophase?

Breakdown of the interphase microtubule display and its replacement by mitotic asters, mitotic aster separation, and chromosome condensation.

What occurs during the prometaphase?

Nuclear envelope breakdown, chromosomes captured, bi-oriented, and brought to the spindle equator.

What occurs during the metaphase?

Chromosomes alligned at the metaphase plate.

What occurs during the anaphase?

APC/C is activated and cohesins degraded, chromosomes move to poles, and spindle pole separation.

What occurs during the telophase?

Nuclear envelope reassembly, assembly of contractile ring.

What occurs during cytokenesis?

Reformation of interphase microtubule array, contractile ring forms cleavage furrow.

What is a somatic cell?

Any cell in the body except for sperm and egg cells.

Name two chemicals used in cancer chemotherapy and their functions in this format: Chemical: Function, Chemical 2: Function

Taxol: Freezes mitotic spindle in actively dividing cells, Vinblastine: Stops formation of spindle

What is a karyotype?

A composite photograph of the chromosomes in a single cell undergoing mitosis.

The cell cycle is regulated at several steps. What could be the result of disturbances in this regulation?

Cancer

What is the level of DNA during G2 of the human liver cell cycle?

Tetraploid

The uses of taxol and vinblastine

have similar problems to DDT or penicillin.

What is the level of DNA during G2 of the human liver cell cycle?

Tetraploid

What are the first four phases of meiosis?

Interphase, prophase I, metaphase I, anaphase I

What are the last five phases of meiosis?

Telophase I, Prophase II, Metaphase II, Anaphase II, Telophase II

Homologous chromosomes carry

different versions of the same genes.

Who is the father of genetics?

Gregor Mendel

What did Mendel invent?

A quantitative approach for the study of inheritance.

What are the two types of phenotype?

Recessive and dominant.

Sex-linkage

Genes located on sex chromosomes.

Consequence of sex-linkage

Patterns of inheritance in males and females differ.

LInkage

Two genes found on same chromosome

Consequence of linkage

Linked genes violate principle of independent assortment

Incomplete Dominance

Heterozygotes have intermediate phenotype

Consequence of incomplete dominance

Polymorphism-Heterozygotes have unique phenotype.

Codominance

Heterozygotes have a phenotype of both alleles.

Multiple Allelism

In a population, more than two alleles present at a locus.

Polymorphism

In a population, more than two phenotypes are present.

Pleitropy

A single allele affects many traits

Variation in genetic environment

IN discrete traits, the phenotype assosiated with an allele depends on whcih alleles are present at another gene

Variation in the physical environment

Phenotype influenced by environment experienced by an individual

Consequence of variation in the physical environment

Some genotypes can be associated with different phenotypes

Polygenic inheritance of quantitative traits

Many genes are involved in specifying traits that exhibit continuous variation

What is the gene that determines male sex determination

the SRY gene

Example of environmental influence

Himalayan rabbit

Who discovered the chemical structure of the gene, and in what year was this discovery?

James Watson and Francis Crick in 1953

The human ABO blood group system examples of

Dominance, co-dominance, and recessiveness

Molecular Flow of Genetic Information

How the genotype is converted to the phenotype

Transfer RNA (tRNA)

Match an amino acid to its corresponding mRNA codon

Codon

a sequence of three DNA or RNA nucleotides that corresponds with a specific amino acid to stop signal during protein synthesis.

Elongation

The addition of amino acids to the polypetide chain

What are the tree steps of elongation

Codon recognition, peptide bond formation, and translocation

How is RNA different from DNA?

Bases are CGAU, and is only one strand.

Translation

the process of making proteins

What do ribosomes do?

Translate RNA into proteins.

What reads DNA and makes a copy?

RNA polymerase

Gene Expression

The process by which information flows from DNA to RNA to protein or genotype or phenotype

Pandemic

Occurring over wide geographical area and affecting an exceptionally high proportion of the population

Zoonotic diseases

infectious diseases that can be transmitted form other vertebrate animals to humans.

The lowest level of DNA/protein structure utilized for packing DNA into chromosomes is the while the highest level of condensation of chromosomes occurs in _.

nucleosome : mitotic chromosomes

The most significant genetic event during mitosis is:

distributing a copy of each chromosome to the opposite pole of the cells.

The ABO blood group system is a good example of

codominance and multiple allelism

In the disease hemophilia:

A mother carrying the hemophilia gene (heterozygous) will pass the disease on to a son with a 50% probability

How can a person with an XY genotype have the external genitalia of a woman?

A gene on the Y chromosome that is necessary to generate male genitalia is mutant or missing.

DNA polymerase is the enzyme that adds deoxyribonucleotides into the new DNA strands. Its general mode of action is different on the leading strand than on the lagging strand. Why?

DNA polymerase activity on the leading strand is continuous while DNA replication on the lagging strand is discontinuous or made in small pieces.

Suppose that grain color in wheat is controlled by a single gene. Suppose further that I have two pure bred strains of wheat, one with red grains and one with dark brown grains, resulting from the action of this single gene. I make a hybrid of these and it has dark brown grains. When I cross this hybrid with the red grained strain, which of the following is a likely result?

Half the progeny will have red grains

The alleles of a gene are found at chromosomes.

the same locus on homologous

Most people afflicted with recessive disorders are born to parents who were

not affected at all by the disease.

Which of the following shows the greatest promise as a cancer chemotherapy agent?

a drug that prevents mitotic spindle from forming

Independent orientation of chromosomes at metaphase I of meiosis results in an increase in the number of

possible combinations of characteristics.

Nondisjunction occurs when

members of a chromosome pair fail to separate.

Imagine that beak color in a finch species is controlled by a single gene. A multicolored pattern of color expression is most likely to be an example of

incomplete dominance.

In humans, a property of ear wax is under the control of a single genetic locus, with sticky ear wax dominant to dry. A woman with dry ear wax who married a man with sticky ear wax

would have children with a 50% chance of having sticky ear wax if the man's genome was heterozygous.

Define Heterozygous

A diploid organism's cells contain two different alleles of a gene

Define Homozygous

identical alleles of the gene are present on both homologous chromosomes.

Dengue fever

Is spreading into temperate zones because of climate changes

Suppose you find in a forensic analysis that a crime sample matches all 14 of the standard DNA polymorphisms of a suspect. (That is, the genotype is exactly the same at all 14 standard polymorphic loci). To calculate the chance that this is a coincidence, i.e., the result of a random match, what information do you need?

The frequency of each of these polymorphic alleles in the population.

Suppose you want to clone a bacterial gene in yeast. Which of the following steps do you NOT have to do?:

a. Isolate mRNA from the bacteria

b. Mix the bacterial gene with vector DNA

c. Transform the yeast with recombinant DNA

d. Screen yeast cells for the bacterial gene sequence.

Isolate mRNA from the bacteria

4) The concept of alleles has been extended to noncoding sequences in DNA, such as STR sequences. These alleles can be tracked in pedigrees and compared with in order to identify genes that cause disease.

health records in the pedigree

In the lac operon in E. coli, covered in class, suppose there is a mutation that completely deletes the operator sequence. In this mutant, which of the following characteristics would be found?

the cell is always making enzymes for the utilization of lactose, even when no lactose is available

A sequence in a certain stretch of DNA is

5'P-AGTCCGG-3'OH.

The RNA transcribed from this template would therefore have the sequence

. 5'-CCGGACU-3'OH

7) _ is an example of post-translational modification of proteins

Insulin

Why does a DNA strand grow only in the 5' to 3' direction?

because DNA polymerases can only add nucleotides to the 3' end of the growing molecule

Which of the following enzymes is used by viruses and in biotechnology applications to synthesize DNA on an RNA template?

reverse transcriptase

Which of the following statements about the treatment or prevention for a prion infection is true?

There is no known treatment or cure for prion infections.

In female mammals, the inactive X chromosome in each cell

is transcriptionally inactive.

The number of proteins in humans

is much greater than the number of genes.

describe the function of tRNA

Transferes amino acids to ribosomes for the synthesis of proteins

describe the function of mRNA

carries the coding instructions for polypeptide chains from DNA to the ribosome