Purdue Bio 111 Exam 1

Which process describes cell division in prokaryotic organisms?

binary fission

What is the term used to describe about 150 nucleotides of DNA wrapped around a core of histone proteins?

nucleosome

Meiotic cell division plays a key role in which biological processes?

sexual reproduction

During the G1 phase of the cell cycle, most of the DNA would be in what state of compaction?

30-nm fiber

During telophase of mitosis, how many DNA double helices make up a single chromosome?

one

A cell starts with 40 chromosomes (20 homologous pairs). After DNA replication how many chromosomes does that cell have?

40 (homologous pairs)

Catenins are proteins that link one cell to another into unified tissues. Loss of function mutations to catenins cause loss of contact inhibition. Normally functioning catenins are best catergorized as what type of protein?

tumor supressor genes

During which phase of the cell cycle does the nuclear envelope reassemble?

Telophase

Disruption of the signaling of growth factors will directly affect which of the cell cycle check points?

G1

Which of the following conditions is required to proceed from metaphase to anaphase?

seperase is active

Which two processes are most similar compared to each other?

meiosis II and mitosis

A cell starts with 40 chromosomes (20 homologous pairs). After meiosis I what is the arrangement of chromosomes in each cell?

20 chromosomes; each with two nonidentical chromatids

Which of the following is true regarding chromosomes during different forms of cell division?

None of the above are true

At what point of cell division are the nuclei of cells undergoing meiosis first considered haploid nuclei?

After telophase of meiosis I

A toxin that prevented the formation of vesicles inside of a cell would most disrupt which process?

cytokinesis in plants

What do we mean when we use the terms monohybrid cross and dihybrid cross?

a dihybrid cross involves organisms that are heterozygous for two characters, and a monohybrid cross involves only one

What was the most significant conclusion that Gregor Mendel drew from his experiments with pea plants?

traits are inherited in discrete units, and are not the results of "blending"

Which of the following differentiates between independent assortment and segregation?

The law of independent assortment requires describing two or more genes relative to one another

Two plants are crossed, resulting in offspring with a 3:1 ratio for a particular trait. What does this suggest?

that parents were both heterozygous for a single trait

flower position is a trait inherited in true mendelian fashion; A=axial, a=terminal. What is the genotype of a pea plant with axial flowers if a test cross with that pea plant yields offspring, all of which have axial flowers?

AA

What is the probability of the genotype aaBBcc appearing in the offspring a Mendelian cross of parents with the genotypes aaBbCc x aaBbcc?

1/8

In cattle, roan coat color (mixed red & white hairs) occurs in the heterozygous (Rr) offspring of red (RR) and and white (rr) homozygotes. Which of the following crosses would produce offspring in the ratio of 1 red: 2 roan: 1 white?

roan x roan

cystic fibrosis results from a single gene mutation and affects the lungs, pancreas, the digestive system, and other organs resulting in symptoms ranging from breathing difficulties to recurrent infections. Which of the following terms best describes this?

pleiotropy

a woman who has blood type A has a daughter who is type O and a son who is type B. Which of the following is a possible partial genotype for the son?

I^B i

When thomas..crossed his red-eyed F1 generation flies to each other, the F2 generation included both red and white eyes flies. remarkably, all the white eyes flies were male. What was this explanation?

the gene involved is on the X chromosome

Males are more often affected by the sex-linked traits than females becuase

males are hemizygous for the X chromosome