genetics ch. 2 review
Cells that are metabolically active, but not destined to proliferate are said to be in _______.
G0 phase
The stage at which "sister chromatids go to opposite poles" immediately follows which of the stages listed below? a) mitotic metaphase b) metaphase of meiosis I c) metaphase of meiosis II d) mitotic metaphase and metaphase of meiosis I e) mitotic metaphase and metaphase of meiosis II
mitotic metaphase and metaphase of meiosis II
If a typical somatic cell has 64 chromosomes, how many chromosomes are expected in each gamete of that organism?
32
The diploid chromosome number of an organism is usually represented as 2n. Humans have a diploid chromosome number of 46. What would be the expected haploid chromosome number in a human?
23
The house fly, Musca domestica, has a haploid chromosome number of 6. How many chromatids should be present in a diploid, somatic, metaphase cell?
24
Which of the following could occur if a cell cycle checkpoint was missed? a) DNA would mutate during G2. b) An unreplicated chromosome could be put through mitosis. c) The cell cycle would be arrested until the error could be corrected. d) Cohesin could not function correctly. e) The spindle apparatus would not form.
An unreplicated chromosome could be put through mitosis.
During interphase of the cell cycle, ________.
DNA content essentially doubles Submit
t/f: The longest stage of interphase is G2.
False.The longest stage of interphase is S; cells typically spend about 7 hours in this stage. The shortest stage of interphase is G2 (3 hours), although the shortest stage of the entire cell cycle is mitosis (1 hour).
Checkpoints are points between phases of the cell cycle at which a cell determines whether all the requirements necessary for each phase of the cell cycle have been properly satisfied. For example, because a cell with damaged DNA can lead to cancer if it is allowed to divide, a cell with damaged DNA usually arrests the cell cycle until the damage can be repaired. At which phase(s) of the cell cycle would a cell normally check for the integrity of its DNA? a) G1/S phase only b) G2/S phase only c) M phase d) G1/S and G2/M phases
G1/S and G2/M phases
During which stage of prophase I does crossing over take place?
Pachynema
What is the arrangement of chromosomes during metaphase?
Sister chromatids align along the equatorial plane of the cell.
Which of the following is true about the second meiotic division?
Sister chromatids are pulling apart.
Which of the following statements about meiosis is true? a) The chromosome number is doubled. b) The chromosome number stays the same. c) Two identical cells are produced. d) The chromosome number is reduced by one-half.
The chromosome number is reduced by one-half. Submit
In humans, what is a fundamental difference between the production of female gametes and male gametes?
The production of female gametes but not male gametes involves an unequal division of cytoplasm.
Which of the following is true about sex-determining chromosomes? a) They act like homologous chromosomes during meiosis so each gamete will get one sex chromosome. b) They are independent during meiosis. c) They have the same gene configuration and same loci. d) They are always metacentric. e) They do not participate in meiosis.
They act like homologous chromosomes during meiosis so each gamete will get one sex chromosome.
A __________ chromosome has its centromere located very close to, but not on, the end of the chromosome.
acrocentric
Which chromosome has a telomere but the p arm is much shorter than the q arm?
acrocentric
The centromere of a chromosome separates during ________.
anaphase
During meiosis, chromosome number reduction takes place in ________.
anaphase I
When do sister chromatids separate during meiosis?
anaphase II
Which of the following are the areas where chromatids intertwine during meiosis?
chiasma
Name two cellular organelles, each containing genetic material, which are involved in either photosynthesis or respiration.
chloroplasts and mitochondria
What significant genetic function occurs in the S phase of the cell cycle?
dna synthesis
Living organisms are categorized into two major groups based on the presence or absence of a nucleus. What group is defined by the presence of a nucleus?
eukaryotic organism
Electron microscopy of metaphase chromosomes demonstrated various degrees of coiling. What was the name of the model that depicted this process?
folded-fiber
When cells withdraw from the continuous cell cycle and enter a "quiescent" phase, they are said to be in what stage?
g0
During which stage can cells either exit the cell cycle or become committed to completing the cell cycle?
g1
After meiosis II, ________ would be formed.
monads
Which if the following is not a source of genetic variation in meiosis? a) law of independent assortment b) polar body formation c) crossing over d)tetrad formation e) the random lining up of chromosomes on the metaphase plate
polar body formation
Which condition is evaluated at the G2/M checkpoint? a) Precise replication of DNA b) Proper spindle formation c) Adequate cell size d) Proper spindle assembly
precise replication of dna
Which term describes meiosis I? a) reducational b) multiplicative c) equinational d) middling e) confrontational
reducational
The nucleolus organizer region (NOR) is responsible for production of what type of cell structure?
ribosome
Which of the following cell structures is directly involved in protein synthesis? a) chloroplasts and mitochondria b) nucleus and plasma membrane c) rough endoplasmic reticulum and ribosomes d) smooth endoplasmic reticulum and the nucleus
rough er and ribosomes
Which part of interphase does DNA duplication take place?
s
What is the outcome of synapsis, a significant event in meiosis?
side-by-side alignment of homologous chromosomes
t/f: A tetrad is composed of one pair of homologous chromosomes at synapsis of prophase I.
true
The meiotic cell cycle involves ________ number of cell division(s) and ________ number of DNA replication(s).
two; one