In humans, meiosis produces cells that are ______________.
haploid, called gametes.
During meiosis, homologous chromosomes separate at __________.
anaphase I
Crossing over between homologous chromosomes normally occurs during _____________.
prophase I
During which phase of the cell cycle does DNA replication occur?
S
Why are no two gametes exactly alike genetically?
Because each gamete has a different combination of parental chromosomes that is the result of both crossing over and independent assortment
While working in a medical clinic, you are asked to assist in the care of a 16-year old female patient who has not yet begun menstruating. You also notice that she is small in stature and has a wider than average neck.
You suspect that she might have ____
Turner syndrome
If a cell begins meiosis with a 2n (diploid) number of 16, how many chromosomes are there in the cell at prophase I?
16
Homologous chromosomes __________.
carry the same genes
A human somatic (body) cell has __________ chromosomes.
46 (23 pairs)
If a cell begins meiosis with a 2n (diploid) number of 16, how many chromosomes are there in each cell at metaphase II?
16
Plant cells divide by __________.
mitosis followed by cytokinesis by cell plate formation
A karyotype __________.
is a picture of a chromosomes arranged in ordered pairs
The sex of a human fetus is determined by the __________.
sex chromosome found in the sperm
Which of the following is the last stage of mitosis?
telophase
If a cell has 30 chromosomes before mitosis, how many does each daughter cell have afterward?
30
Which of the following allows sexual reproduction to occur generation after generation?
Meiosis
Which of the following terms describes a failure of chromosomes to sort properly during meiosis?
Nondisjunction
A human skin cell, in prophase of mitosis, contains 46 chromosomes. How many chromatids does it contain in total?
92
Which of the following is true about prophase I?
It involves pairing up of homologous chromosomes
The number of chromosomes found in a somatic eukaryotic cell __________.
is constant during its entire life
Which of the following is true about meiosis II?
It results in the production of four haploid cells
How does meiosis generate genetic diversity?
Homologous chromosomes cross over during prophase I, and during metaphase I, chromosomes align randomly.
If a cell begins meiosis with a 2n (diploid) number of 16, how many chromosomes are there in the cell at anaphase I?
16
Diploid cells become haploid during __________.
meiosis I
In meiosis II, __________.
sister chromatids are separated into different daughter cells