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
T/F- A cancer cell lives longer than a normal cell
False
T/F- A cancer cell uses fewer nutrients than a normal cell
False
T/F- A cancer cell usually does not contain a nucleus
False
T/F- A cancer cell is typically more than ten times as large as a normal cell
False
In sexually reproducing multicellular organisms, the main functions of mitosis are____.
A) Reproduction (production of gametes)
B) Growth and Development
C) Tissue repair/replacement of damaged cells
B) Growth and Development
C) Tissue repair/replacement of damaged cells
Which events occur during prophase?
1- Chromosomes condense and are attached to spindle fibers
2- The nuclear envelope breaks down
What event finishes mitosis by dividing the cytoplasm and organelles of the original parent cell into two separate daughter cells
Cytokinesis
During this phase in the cell cycle, the cell carries out its normal functions and the chromosomes are thinly spread out throughout the nucleus. What is the phase?
Interphase
Looking through a light microscope at a dividing cell, you can see two separate groups of chromosomes on opposite ends of the cell. New nuclear envelopes are taking shape around each group. The chromosomes then begin to disappear as they unwind. You are witnessing____.
Telophase
What are most human cancers caused by?
An accumulation of mutations
Cells that are about to divide replicate their DNA at what phase?
Interphase
In what phase do microtubules form their mitotic spindle, and then the nuclear envelope breaks up
Prophase
In what phase does the mitotic spindle fully form and chromosomes are lined up in the center of the cell
Metaphase
In which phase do sister chromatids separate and become full-fledged chromosomes that move to opposite poles?
Anaphase
In which phase do chromosomes become less condensed and new nuclear envelopes forms?
Telophase
T/F- In cytokinesis, the cytoplasm divides
True
Accidents can occur in meiosis wherein members of a chromosome pair fail to separate at anaphase. This is called?
Nondisjunction
Orientation of homologous pairs of chromosomes at metaphase 1 result in alternative arrangements that contribute to genetic variation in offspring. The orientation is called____.
Independent Assortment
Bacteria divides by?
Binary Fission
The first step of bacterial replication is____.
DNA replication
What is different concerning the DNA in bacterial cells as supposed to eukaryotic cells?
A) amount of DNA present
B) whether the DNA is housed in a nucleus or not
C) whether the DNA is linear or circular
D) all of the above
D
The exchange of corresponding portions of homologous chromosomes is referred to as?
Crossing Over
Meiosis and cytokinesis result in the formation of
4 haploid cells
Which term is used to describe the way homologous pairs of chromosomes line up in random orientations relative to each other during metaphase 1?
Independent Assortment
Sexual reproduction requires the cellular process of ___ followed by_____.
Meiosis and fertilization
Which of the following is true of the following statements?
A) Asexual reproduction requires the production of eggs and sperm
B) Geneticists use the terms son and daughter to distinguish b/w cells resulting from cell division
C) Meiosis results in gametes that are used in reproduction
D) The sperm and egg have twice as many chromosomes as the parental cells.
C) Meiosis results in gametes that are used in reproduction
During which phase both the contents of nucleus and the cytoplasm are divided?
Mitotic Phase
During which phase do cells grow and replicate both its organelles and its chromosomes.
Interphase
Which of the following statements applies to sexually reproducing species but not asexually reproducing species?
A) Two kinds of cell division are required
B) The two “daughter” cells that result from cell division following mitosis are genetically identical to each other and to the original “parent” cell
C) Reproduction can occur with either one or two parents
D) Offspring are able to reproduce
A) Two kinds of cell division are required
What is the function of meiosis?
Reproduction (production of gametes)
Looking through a light microscope at a cell undergoing meiosis, you see that the chromosomes have joined into XX-shaped tetrads. These tetrads lined up along a plane that runs through the center of the cell. This cell is in____.
Meiosis 1
Meiosis starts with____ cells and produces_____ gametes.
diploid and haploids
How many steps does meiosis typically take?
3 steps. All of the chromosomes are duplicated in a diploid cell, and there are two cell divisions to produce a total of 4 haploid gametes
What separates in meiosis 1?
homologous chromosomes
What separates in meiosis 2?
Sister Chromatids
List 3 forms of cancer treatment
Surgery
Radiation Therapy
Chemotherapy
Carcinogen example of colon and rectum cancer is?
High Dietary Fat; low dietary fiber
Carcinogen example of lymphomas and cervix cancer is?
Viruses
Carcinogen example of lung, bladder, kidney, pancreas, stomach and cervix is
Cigarette Smoke
Carcinogen example of breast/ uterus and prostate is?
breast/uterus- estrogen
prostate- testosterone
Carcinogen example of skin is?
UV light
Carcinogen example of leukemia is?
x-rays
What was the first anti-cancer vaccine?
Gardasil
When 2 daughter cells are produced they are genetically identical to each other and parent cell it is called?
Cell Division
Single-celled organisms reproduce by simple cell division
Amoeba
Some multicellular organisms, such as sea stars, can grow new individuals from fragmented pieces.
True
Growing a new plant from a clipping is another example of asexual reproduction.
African Violet
Proteins used to package DNA in eukaryotes is known as?
Histones
What consists of DNA wound around histone molecules?
Nucleosomes
A typical body cell is known as a?
somatic cell
22 pairs of matching chromosomes are called what?
Autosomes
List 2 examples of nondisjunction if they affect the sex chromosomes.
Kleinfelter’s Syndrome
Turner’s Syndrome
What is Kleinfelter’s Sydrome?
a male-sterile
small testes, slighlty enlarged breasts
female-sterile
sex organs don’t mature, extra skin at base neck
only case where having 45 chromosomes are not fatal
Turner’s Syndrome
Cell Cycle has 2 phases what are they?
1-interphase
2- mitotic phase
T/F- G1, S, and G2 fall into the interphase section of the cell cycle?
True
T/F- Mitosis and cytokinesis occur in the mitotic phase of the cycle.
True
Beginning when sister chromatids separate from each other and ending when a complete set of daughter chromosomes has arrived at each of the two poles of the cell
Anaphase
