PAST EXAM QUESTIONS Flashcards
Which of the following proteins keep parental DNA separated during DNA replication?
Single-strand binding proteins
Why can’t the lagging DNA strand be copied continuously like the leading strand?
because DNA polymerase can attach nucleotides in only one direction
What is the function of ligase during DNA replication?
joining Okazaki fragments
Which of the following is true of binary fission?
binary fission results in two daughter cells that are genetically identical to one another
During which phase of the cell cycle does DNA replication occur?
S
What is the term used to describe DNA wrapped around histone proteins?
nucleosome
During which phase of the cell cycle does the nuclear envelope reassemble?
telophase
You see a cell in a mitotic phase with its sister chromatids being pulled towards opposite poles; in which phase is this cell?
anaphase
Which of the following are expected to be identical to one another?
sister chromatids during mitosis
What structure forms first in a plant cell as it undergoes cytokinesis to separate it into two daughter cells?
cell plate
The sites of the physical exchange of DNA between chromatids are known as:
chiasmata
How are Meiosis I and Meiosis II different?
crossing over occurs during Meiosis I but not Meiosis II
Septum formation and cleavage furrow formation
differ because septa are produced by FtsZ protein and cleavage furrows are produced by actin and myosin microfilaments AND are necessary for cells to divide their cytoplasm
A telomere is
made up of repeated DNA sequences at the ends of chromosomes
Primase
synthesizes an RNA primer for DNA polymerase
During replication, DNA is unwound
by helicase at the replication fork
Which of the following is/are true about microtubules?
They are made of protein AND They may attach to kinetochores
The synaptonemal complex
is composed of protein AND forms between non-sister chromatids
Cells containing only one homologue of each chromosome would be produced by the end of:
meiosis I AND meiosis II
Crossing over
involves the reciprocal exchange of genetic material between the non-sister chromatids of homologous chromosomes
During which phase of the cell cycle do the poles of the cell move apart?
anaphase
Cell division in prokaryotes and eukaryotes both involve
segregation of genetic material
An activated cyclin dependent kinase
uh
A cell cycle checkpoint may occur
at the G1 to S transition at the G2 to mitosis transition at the metaphase to anaphase transition
Cells containing homologous pairs of chromosomes would be produced by which of the following processes?
mitosis
Sister chromatids are created during which process?
When DNA is replicated during the S phase
Which of the following is true regarding chromosomes during different forms of cell division?
None of the above are true
Which biological process would be directly affected if meiotic cell division was impaired?
Sexual reproduction
Which of the following are expected to be identical to one another?
Sister chromatids
What will happen to a cell that detects damage to DNA after the S phase of the cell cycle?
It won’t proceed through the G2/mitosis checkpoint until damage is fixed
In what phase of the cell cycle is DNA fully compacted and visible in a cell?
During mitosis
Males are more often affected by sex-linked traits than females because
Males are hemizygous for the X chromosome
The interaction between genes at different loci to determine coat color in Labradors is an example of?
epistasis
Which of the following is true about the F1 offspring from a P0 cross between true-breeding dominant and true-breeding recessive organisms?
They will all have the same phenotype
Transmission of signaling molecules through gap junctions is an example of
cell-to-cell contact signaling
What epigenetic modifications could make DNA more accessible to transcription factors?
Demethylation of cytosines followed by guanines AND Acetylation of histone tails
Hydrophilic ligands
bind to trans-membrane receptors
When histone tails are deacetylated
DNA binds more tightly with the histones because deacetylated lysines make the histones more positively charged
Zymogens are enzymes that are not active until they are
cleaved
Some genes are paternally imprinted and
those genes are only expressed on the maternal chromosome and mutants have enhanced growth.