Biology- Chapter 13
Homologous chromosomes migrate to opposite poles during _____.
anaphase I
During _____ sister chromatids separate.
anaphase II
Human gametes are produced by _____.
meiosis
The shuffling of chromosomes that occurs during both fertilization and _____ can lead to genetic variation. See Concept 13.4 (Page 265)
meiosis
The two homologs of a pair move toward opposite poles of a dividing cell during
meiosis I
If you look through a microscope and see a cell with chromosomes lined up two by two, what stage of cellular reproduction must you be looking at?
meiosis I only
Homologous pairs of chromosomes are lined up independently of other such pairs during _____.
metaphase I
During _____ chromosomes align single file along the equator of a haploid cell.
metaphase II
Of the two processes learned, which is occurring in your hand?
mitosis
Crossing over, resulting in an increase in genetic variation, occurs between _____.
nonsister chromatids of homologous chromosomes
Asexual reproduction _____. See Concept 13.1 (Page 255)
produces offspring genetically identical to the parent
Synapsis occurs during _____.
prophase I
During _____ a spindle forms in a haploid cell.
prophase II
Meiosis II is similar to mitosis in that
sister chromatids separate during anaphase.
In alternation of generations, what is the diploid stage of a plant that follows fertilization called? See Concept 13.2 (Page 258)
sporophyte
At the end of _____ and cytokinesis, haploid cells contain chromosomes that each consist of two sister chromatids.
telophase I
At the end of _____ and cytokinesis there are four haploid cells.
telophase II
What is crossing over? See Concept 13.3 (Page 262)
the exchange of homologous portions of non-sister chromatids
Imagine that I've taken a snapshot of the chromosomes in a hypothetical cell. Part of that snapshot looks like this. What stage of the lifecycle must the cell be in? ( A picture of two sister chromosomes)
the start of meiosis I
Meiosis I produces _____ cells, each of which is _____.
two ... haploid
In diploid cells: mitosis results in the formation of how many cells; meiosis results in the formation of how many cells? See Concept 13.3 (Page 262)
two diploid cells ... four haploid cells
If we continued to follow the cell lineage from question 4, then the DNA content of a single cell at metaphase of meiosis II would be
x
Which of these gametes contains one or more recombinant chromosomes?
B and C
A human cell containing 22 autosomes and a Y chromosome is
a sperm.
Imagine you found a hypothetical organism, you examine one of its gametes and you see that it contains five chromosomes. How many chromosomes will one of its body cells contain just before mitosis begins?
10
A diploid organism whose somatic (nonsex) cells each contain 32 chromosomes produces gametes containing _____ chromosomes.
16
In human gamete production there is an average of _____ crossover events per chromosome pair.
2-3
Normal human gametes carry _____ chromosomes.
23
If the DNA content of a diploid cell in the G1 phase of the cell cycle is x, then the DNA content of the same cell at metaphase of meiosis I would be
2x
What number and types of chromosomes are found in a human somatic cell? See Concept 13.2 (Page 256)
44 autosomes and 2 sex chromosomes
Which of these gametes contain one or more recombinant chromosomes?
B, C, F, and G
Which of these cells is (are) haploid?
C and D
How are sister chromatids and homologous chromosomes different from each other? See Concept 13.3 (Page 260)
Homologous chromosomes contain the same gene loci but may have different alleles of a particular gene. Sister chromatids are identical copies of each other produced during DNA replication.
Which of the following occurs during meiosis but not during mitosis? See Concept 13.3 (Page 262)
Synapsis occurs.
For what purpose(s) might a karyotype be prepared? See Concept 13.2 (Page 256)
The first three answers are correct. or -for prenatal screening, to determine if a fetus has the correct number of chromosomes - to determine whether a fetus is male or female -to detect the possible presence of chromosomal abnormalities such as deletions, inversions, or translocations
Why do some species employ both mitosis and meiosis, whereas other species use only mitosis? See Concept 13.2 (Page 258)
They need both if they are producing plant gametes.
What structure is represented by my waist where I am joined to my twin?
centromere
Which processes lead to most genetic variation in sexually reproducing organisms?
crossing over, independent assortment of chromosomes in meiosis, random fertilization
Heritable variation is required for which of the following? See Concept 13.4 (Page 266)
evolution
Meiosis II typically produces _____ cells, each of which is _____.
four ... haploid