bio 13/15

According to Figure 13.13, the chances that a woman who is age 45 will have a child with Down syndrome is somewhere around ______________.

1 in 30

What is the ploidy of this cell model?--little Xs

2n=6

chapter 15

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Which strand or strands shown here would serve as a template for the lagging strand?

the bottom strand

This figure shows a replication bubble with two replication forks. The DNA in the region of the arrow would support the synthesis of _______ strand of DNA.

the lagging

Which models show a 2n = 8 cell?

the one with 8 noodle outlines

What is the ploidy of this cell model?--3 short w lines, three long w lines

triploid

Chiasma form during meiosis I but not during mitosis

true

During metaphase I, there will be four pairs of chromosomes (tetrads) aligned at the metaphase plate.

true

Each chromosome contains one long molecule of double-stranded DNA and proteins.

true

In this model, the color codes emphasize that two homologous chromosomes contain the same genes

true

Longer stretches of single-stranded DNA are expected on the lagging strand template than on the leading strand template

true

More primers are expected to be used in the synthesis of the lagging strand than in the synthesis of the leading strand

true

The bands on the chromosomes represent certain genes.

true

The chromosomes in the model are replicated

true

The sister chromatids of replicated chromosomes separate during both mitosis and meiosis II

true

There are five different lengths of chromosomes in this cell

true

This cell is 2n = 10

true

This cell is diploid

true

Hershey and Chase used _____ to radioactively label the T2 phage's proteins.

35S

The domestic dog has a diploid number (2n) of 78; 76 of the chromosomes are autosomes and 2 are sex chromosomes (X and Y). A karyotype taken from a dog's mature egg cell would have how many chromosomes?

39

The radioactive isotope 32P labels the T2 phage's _____.

DNA

The enzyme that can replicate DNA is called______

DNA polymerase

Which statement about the difference between homologous chromosomes and sister chromatids is correct

Homologous chromosomes contain the same genes but often different alleles. Sister chromatids contain the same genes and the same alleles.

A student has drawn a series of metaphase I cells to show the principle of independent assortment. Which cell does not belong in the series?

In this series, red and blue are used to distinguish maternal and paternal chromosomes within each homologous pair. However, in this cell, both homologs within each pair are the same color, which is not helpful in showing independent assortment of the homologs. blue XX red XX blue XX

______ are the short sections of DNA that are synthesized on the lagging strand of the replicating DNA.

Okazaki fragments

Which of the following cell models is a correct illustration of metaphase I for a 2n = 4 cell?

Replicated chromosomes line up at the metaphase plate in homologous pairs (tetrads). --four chromosomes in a box like XX XX

Compare the two cells shown in this image. Which of the following statements is correct?

The number of chromosomes in both cells is the same, but the bottom cell contains twice the amount of DNA as the top cell.

Which metaphase cell could have produced these gametes?

The replicated homologous chromosomes are lined up in pairs during metaphase I of meiosis, with the three smallest red chromosomes on the same side as the largest blue chromosome.

Based on the purifying selection hypothesis, how would changes in the rate of mutation influence whether sexual or asexual reproduction is favored?

Under high mutation rates, sexual reproduction is favored.

Which of the following hypothetical changes would eliminate the need to synthesize a lagging strand?

allowing DNA synthesis to occur in both the 5' to 3' and 3' to 5' directions

What are homologous chromosomes

chromosomes that are similar in their size, shape, and gene content

After replication is complete, the new DNAs, called daughter DNA, are identical to each other

daughter DNA

Homologous chromosomes form pairs during both mitosis and meiosis

false

Since independent assortment can occur in different ways during meiosis, two people could come up with different color-combinations of chromosomes in their drawings of gametes, and both be correct.

false

The chromosomes are replicated

false

The color codes in this model will help to show independent assortment.

false

The rate of DNA synthesis from each primer is expected to be faster on the leading strand than on the lagging strand

false

The template DNA for the leading strand is easier to unwind than the template DNA for the lagging strand

false

The total number of chromosomes is reduced by half during both mitosis and meiosis

false

There are 16 chromosomes in the model

false

in this model, the color codes emphasize that two homologous chromosomes contain the same alleles

false

What is the ploidy of this cell model?

haploid (one set) Each of the chromosomes in the cell is a different length so you can infer that each has unique genetic information.

Who demonstrated that DNA is the genetic material of the T2 phage?

hersey and chase

After allowing phages grown with bacteria in a medium that contained 32P and 35S, Hershey and Chase used a centrifuge to separate the phage ghosts from the infected cell. They then examined the infected cells and found that they contained _____, which demonstrated that _____ is the phage's genetic material.

labeled DNA ... DNA

The new DNA strand that grows continuously in the 5' to 3' direction is called the

leading strand

What stage of cell division does this image show?

metaphase of mitosis Note these hallmarks of metaphase of mitosis in a diploid cell: how the chromosomes are the same size and shape with one being a maternal chromosome (shown in red) and the other being a paternal chromosome (shown in blue) how the chromosomes are not paired but aligned one above another

What is the ploidy of this cell model? (blue squiggles)

n=6

this image is of a

phage

During DNA replication, an open section of DNA, in which a DNA polymerase can replicate DNA, is called a

replication fork

A particular plant species can reproduce both sexually and asexually. When samples of this plant are grown in an environment where a harmful bacterial pathogen is abundant, the plants that survive are likely to have been produced primarily through what type of reproduction?

sexual

Which of the following gametes could result from the cell shown? (Assume that meiosis proceeds normally.)

singular short black one, medium and long blue ones. single chromosomes

Review the checklist of tips for drawing chromosomes during independent assortment. Four of the tips were followed, but one was not. Which one?

start with replicated chromosomes