Chapter 10 Mastering Biology Flashcards
Which of the following statements correctly describes an organism’s genome?
A genome is a complete set of all of an organism’s genes.
If a horticulturist breeding plants known as gardenias succeeds in having a single plant with a particularly desirable set of traits, which of the following processes would be her most probable and efficient route to establishing a line of such plants with that particular set of traits?
Clone the plant asexually to produce an identical one.
In a human karyotype, chromosomes are arranged in 23 pairs. If we choose one of these pairs, such as pair 14, which of the following characteristics are most likely for the two chromosomes of the pair to have in common?
length, centromere position, staining pattern, and traits coded for by their genes
The somatic cells of a type of shrub called a privet each contain 46 chromosomes. To be as different as they are from human cells, which have the same number of chromosomes, which of the following must be true?
Genes of privet chromosomes are significantly different from those in humans.
A given organism has 46 chromosomes in its karyotype. Which of the following statements is correct regarding this organism?
a) It must be sexually reproducing.
b) It must be human.
c) Its gametes must have 23 chromosomes.
d) It must be an animal.
Its gametes must have 23 chromosomes.
Which of the following types of cells would be produced by meiosis?
a) a haploid animal cell
b) a diploid unicellular organism
c) a diploid plant cell
d) a diploid animal cell
a) a haploid animal cell
To visualize and identify meiotic cells at metaphase I with a microscope, what would you look for?
pairs of homologous chromosomes all aligned at the cell’s center
If chiasmata can be seen in a cell under a microscope, which of the following meiotic processes must have occurred?
prophase I
During mitosis or meiosis, sister chromatids are held together by proteins referred to as cohesins. Such molecules must have which of the following properties?
a) They must be intact for nuclear envelope re-formation.
b) They must be removed before meiosis can begin.
c) They must persist throughout the cell cycle.
d) They must be removed before sister chromatids or homologous chromosomes can separate.
d) They must be removed before sister chromatids or homologous chromosomes can separate.
Which of the following events occurs in meiosis but not in mitosis?
synapsis of pairs of homologous chromosomes
Which of the following processes happens during meiosis I?
a) The chromosome number per cell is conserved.
b) Homologous chromosomes of a pair are separated from each other.
c) Sister chromatids are separated.
d) Four daughter cells are formed.
b) Homologous chromosomes of a pair are separated from each other.
How do cells at the completion of meiosis compare with cells that have replicated their DNA and are just about to begin meiosis?
They have half the number of chromosomes and one-fourth the amount of DNA.
When homologous chromosomes cross over, what is the result?
Specific proteins break the two strands of nonsister chromatids and re-join them.
Independent assortment of chromosomes during meiosis is a result of
the random and independent way in which each pair of homologous chromosomes lines up at the metaphase plate during meiosis I.
Why are cells arrested at metaphase in the preparation of a karyotype?
All of their chromosomes are highly condensed and easy to visualize.
Look at the cell in the figure. Based on this figure, which of the following statements is true?
This cell is diploid.
What is the best evidence telling you whether this cell is diploid or haploid?
The cell is diploid because it contains two sets of chromosomes.
This chromosome has two chromatids, joined at the centromere. What process led to the formation of the two chromatids?
The two chromatids were formed by duplication of a chromosome.
Which phase of meiosis is represented in the figure above?
anaphase I
Which phase of meiosis is represented in the figure above?
metaphase II
You have isolated DNA from three different cell types of an organism, determined the relative DNA content for each type, and plotted the results on the graph shown in the figure above. Which sample(s) of DNA might be from a germ cell arrested in prophase I of meiosis?
II
You have isolated DNA from three different cell types of an organism, determined the relative DNA content for each type, and plotted the results on the graph shown in the figure above. Which sample(s) of DNA might be from a cell at the end of anaphase II of meiosis?
III
Look at the cell in the figure below.
This cell must be undergoing ______ because ______ are associated with each other at the metaphase plate and chiasmata are present.
meiosis; homologous chromosomes
