Science Homework Help

LAST SET

A new chemotherapy drug has been developed and it stopes the production of the

microtubules that are used to create the spindle fibers? Why is this an effective chemotherapy medication?

• It prevents meiosis so patients with cancer cannot pass on the disease
• It prevents cytokinesis, so new cells cannot form a tumor
• It prevents DNA replication during the S phase
• It prevents sister chromatids from pulling apart during anaphase of mitosis

Bacterial infections have become much more of a threat to human health due to which of the following?

• A an increase in acquired antibiotic resistance by innocuous strains
• B horizontal transfer of pathogenicity
• C an increased use of antibiotics, horizontal transfer of pathogenicity, and an increase in acquired antibiotic resistance by innocuous strains
• the increased use of antibiotics
• D an increased use of antibiotics coupled with an increase in acquired antibiotic resistance by innocuous strains

Linked genes generally do not follow the laws of independent assortment.

• are polygenic.
• show pleiotropy.
• reflect a pattern of codominance.

In mice, the gene for insulin-like growth factor is imprinted.  During embryonic development, only the paternal allele for insulin-like growth factor is expressed.  This means:

• that the paternal allele is hyper-methylated.
• that the maternal allele is expressed.
• that the paternal allele is mutated.
• that the maternal allele is imprinted.
• that the paternal allele is imprinted. (my guess)

Which of the following diseases is not caused by a mutation in a mitochondrial gene?

• Turner syndrome
• Leber’s Inherited Optic Neuropathy (LHON)
• secretion of lactic acid into the bloodstream: neurogenic muscle weakness
• myoclonic epilepsy
• cardiomyopathy (this is my guess)

Which of the following is FALSE of epigenetic inheritance?

• It affects the phenotype.
• It occurs during gamete or early embryonic formation.
• It may be passed on to offspring.

Mitosis results in the formation of two genetically identical daughter cells. This is because:

• after replication, the material is compared and corrected to be identical.
• the chromosomes pair up (synapse) in prophase as a counting mechanism.
• all the genetic material is duplicated then segregated equally to the daughter cells.
• daughter cells are initially haploid, but they duplicate their chromosomes to become diploid again.
• the number of chromosomes needs to be reduced before cytokinesis.

A horticulturist is breeding a new variety of houseplant in which two genes control leaf color. G (allele for green) is dominant to g (yellow) and B (second allele for green) is dominant to b (yellow). The recessive homozygous condition of either gene will mask a dominant allele. What color is a plant with the genotype Ggbb?