Bio Chapter 8 and 11 Flashcards
In humans, meiosis produces cells that are___.
haploid, called gametes
A picture of chromosomes arranged in ordered pairs
Karotype
During which phase of the cell cycle does DNA replication occur?
S
A human somatic (body) cell has____ chromosomes.
46
Diploid cells become haploid during which stage?
Meiosis 1
A human skin cell, in prophase of mitosis, contains 46 chromosomes. How many chromatids does it contain in total?
92
Homologous chromosomes cross over during prophase 1, and during metaphase 1, chromosomes align randomly.
Process of meiosis generating genetic diversity
Which of the following is true about prophase 1?
A) it involves division of cytoplasm
B) condensed chromosomes begin to uncoil to form chromatin
C) occurs during mitosis
D) involves pairing up homologous chromosomes
E) can occur only during healing
D) involves pairing up homologous chromosomes
During meiosis, homologous chromosomes separate at which phase?
Anaphase 1
In which phase do sister chromatids are separated into different daughter cells?
Meiosis 2
T/F- Plant cells divide by meiosis followed by cytokinesis by cell plate formation
False, plant cells divide by mitosis followed by cytokinesis by cell plate formation
If a cell begins meiosis with a 2n(diploid) number of 16, how many chromosomes are there in the cell at prophase 1?
16
Which of the following is true about meiosis 2?
A) It results in the production of four haploid cells
B) requires homologous chromosomes to pair up
C) results in the production of two haploid cells
D) results in cells that have 2 complete sets of chromosomes
E) it is a process by which genetic material is exchanged between homologous chromosomes
A) It results in the production of four haploid cells
The sex of a human fetus is determined by the____?
sex chromosomes found in sperm
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 anaphase 1?
16
Crossing over between homologous chromosomes normally occurs during which stage?
Prophase 1
Which of the following allows sexual reproduction to occur generation after generation?
Meiosis
If a cell begins meiosis with a 2n (diploid) number of 16 how many chromosomes are there in each cell at metaphase 2?
8
What do homologous chromosomes carry?
carry the same genes
A failure of chromosomes to sort properly during meiosis is known as?
Nondisjunction
If a cell has 30 chromosomes before mitosis, how many does each daughter cell have afterward?
30, because of mitosis. The purpose of mitosis is to turn a single parent cell into 2 genetically identical daughter cells. Therefore, if the parent cell has 30, then each daughter cell will also have 30 after mitosis
What occurs when alleles for the same trait separate during gamete formation
Segregation
What is the last stage of mitosis?
Telophase
Why are no two gametes exactly alike?
Because each gamete has a different combination of parental chromosomes that is the result of both crossing over and independent assortment
What order does the cell cycle occur in?
G1, S, G2, Mitosis, Cytokinesis
Inheritance of certain genes increases the risk of getting certain cancers; thus, it can be said that_____.
predisposition to these cancers is inherited
List the 4 main stages of meiosis in order
Prophase, Metaphase, Anaphase, and Telophase
Which of the following best describes cancer cells?
A) They will divide a certain number of times and then stop
B) They are more highly differentiated than normal cells
C) They produce toxic compounds
D) Controls governing cell division have been altered
E) Proto-oncogenes control their cell divison
D) Controls governing cell division have been altered
What name is given to a gene that causes cancer?
Oncogene
Replication of chromosomal DNA occurs when?
before a cell divides
All your cells contain proto-oncogenes, which can change into cancer-causing genes. Why do cells possess such potential time bombs?
Proto-oncogenes are necessary for normal control of cell division.
Which of these is a carcinogen?
A) cigarette smoke
B) fat
C) testosterone
D) UV light
E) all of them
E) all of them
__ is carcinogen that promotes colon cancer.
Fat
The genes that malfunction and cause a cell to become cancerous usually___.
regulate cell division
Most of an organism’s DNA is carried by its___.
Chromosomes
Events of Mitosis in order
1) Interphase
2) Prophase
3) Metaphase
4) Anaphase
5) Telophase and cytokinesis
T/F- A cancer cell does not respond to the signals that control cell division
True