BIO EXAM CH 11 LEARNING CURVE

First-division nondisjunction will only yield gametes with an extra chromosome, whereas second-division nondisjunction will only yield gametes missing a chromosome.

false

Crossing over occurs during which step in meiosis?

prophase 1

Evidence exists (especially in dinoflagellates) that mitosis evolved from binary fission. For example, in certain eukaryotic cells during mitosis, DNA is attached to the membrane of the nucleus (much like a circular chromosome of a bacterium is attached to the plasma membrane).

true

Nondisjunction can occur in both mitosis and meiosis.

true

In human cells, at the end of mitosis and after cytokinesis, how many chromatids have moved into each daughter cell?

46

The process of cell division in a prokaryotic cell is called:

binary fission

Non-sister chromatids are:

copies of homologs but not fully identical chromosomes.

Some types of leukemia are the result of constitutively active (that is, "always on") growth factor receptors.

true

To visualize chromosomes, a picture of each can be arranged such that homologous chromosomes are aligned with each other and arranged as pairs in order of decreasing size. What is this called?

a karyotype

The prokaryotic protein FtsZ is evolutionarily related to eukaryotic tubulin. What does this mean? -All of these choices are correct. - The amino acid sequence for FtsZ is similar to tubulin. -The overall protein structure of FtsZ is similar to tubulin. -The two proteins evolved from a common ancestral protein. -The gene sequence for FtsZ is similar to tubulin.

All of these choices are correct.

Which of the answer choices is a characteristic of meiotic cell division?

Meiotic cell division results in halving the number of chromosomes.

Which statement regarding tumor suppressors are true?

Mutations affecting tumor suppressors can contribute to the development of cancers.

Suppose a research team does a detailed analysis of the DNA sequence of all three copies of chromosome 21 from an individual with trisomy 21 (Down syndrome). They discover that two of the three chromosomes are essentially identical in sequence, whereas the third chromosome has a significant number of sequence differences. Which of the answer choices is consistent with this observation?

The extra chromosome 21 resulted from second-division nondisjunction in one of the parents' gametes.

A researcher is evaluating the expression of p53 in cells she is culturing in the laboratory. She notices that in a small group of cells, high levels of phosphorylated p53 occur in the nuclei. What can she deduce about these cells?

These cells likely contain damaged DNA.

Which cellular conditions promote progression of the cell cycle? All of these choices are correct. the accumulation of cyclins the activation of CDKs the expression and synthesis of cyclin proteins binding of cyclins to CDKs

all of these choices are correct

During meiosis I:

diploid cells become haploid.

Synapsis is best described as:

the pairing of homologous chromosomes in prophase I.

A _____ is an enzyme that adds phosphate groups to other proteins. If this enzyme is only active when bound to a specific protein that fluctuates in concentration in synchrony with the cell cycle, then it is a _____.

cyclin; cyclin-dependent kinase