Exam 3 Flashcards
Crossing over occurs in which phase of Meiosis?
Prophase I
During mitosis in human somatic cells, a metaphase cell has __________ chromatids and _________ chromosomes. Immediately after cytokinesis, each daughter cell will have _______________ chromatids and _______ chromosomes.
92, 46, 0, 46
Human cells have a diploid number of chromosomes except in which of the following?
Ova
Which of the following structures are depolymerized during anaphase of mitosis leading to the separation of sister chromatids?
Kinetochore microtubules
In humans cells, ________chromosomes line up in the metaphase plate during meiosis II. After telophase II and cytokinesis, each daughter cell will have ________ chromosomes
23, 23
Which of the following will contribute to genetic diversity during meiosis and during fertilization?
1) Random fertilization
2) Independent assortment of chromosomes
3)Crossing over between non-sister chromatids
Errors in meiosis (nondisjunction) are most likely to happen during which stages?
Anaphase I and II
Which of following about MPF is true?
1)It cannot break down cyclin dependent kinases
2) it is often referred to as a “suicide protein”
3) it is a complex of cdk and cyclin
They are all true
During which part of the cell cycle are chromosomes replicated?
Interphase (specifically S)
True or False: Sister chromatids separate during anaphase of Mitosis and Meiosis II
True
True/False: In metaphase, homologous chromosome pairs line up during Meiosis I whereas duplicated chromosomes line up single file during Mitosis
True
True/False: Crossing over occurs between non-sister chromatids while in tetrad configuration during prophase I
True
True/False: Chromosome replication happens during S phase of the mitotic cell cycle and during prophase of meiosis II.
False
What happens to a RBC when it is placed in a hypertonic solution?
It crenates (shrivels)
What happens to a RBC when it is placed in a hypotonic solution?
It lyses (the water comes rushing in like the Kool Aid Man)
What happens to a RBC when it is placed in a isotonic solution?
Nothing its straight chillin
Which amino acid residues are aquaporins primarily comprised of?
Asn-Pro-Ala
A lot of Alpha helices to facilitate diffusion
How do steroid hormones cross the cell membrane?
Receptor mediated endocytosis
Where would you find receptors with glycoproteins and what kind of ligands would they bind to?
Outside cell
Large polar molecules
Which enzyme helps create cAMP as part of the GPCR transduction pathway?
Adenyl Cyclase
Which of the following is not a secondary messenger?
A) Ca2+
B) Pip2
C) IP3
D)ATP
E) DAG
D)ATP
What is the contractile ring formed during telophase comprised of?
Microfilaments = actin and myosin
In a protein kinase cascade the signal is ____________ at each step while multiple steps provide __________________
1) amplified
2) specificity
Which portion of the IP3/DAG Second-Messenger System is hydrophobic?
DAG - found in membrane
hich portion of the IP3/DAG Second-Messenger System is hydrophillic?
IPS - found in cytoplasm
How does cell signaling accomplish specificity?
-Different receptors
Different relay proteins
Crosstalk
All yield different responses (example Epinephrine causes bronchodilation through relaxation in the lungs but increases cardiac contractility and heart rate)
What are cyclin dependent kinases activated by? What kind of regulation is this?
Activated by binding to cyclin
2) allosteric regulation
The progression past the G1-S transition phase depends on phosphorylation to inactivate which protein?
Retinoblastoma protein
Each nucleosome is comprised of how many histone molecules?
8 (1 histone octamer)
Where is H1 histone located?
Outside of the octamer and links the DNA to the octomer to form the nucleosome structure
