Kaplan Biology Questions Flashcards
Which of the following is the correct sequence of the development of a mature sperm cell?
Spermatid → spermatocyte → spermatogonium → 2 ° spermatocyte → spermatozoan
Spermatogonium → 1 ° spermatocyte → 2 ° spermatocyte → spermatid → spermatozoan
Spermatozoan → 1 ° spermatocyte → 2 ° spermatocyte → spermatogonium → spermatid
Spermatogonium → 1 ° spermatocyte → 2 ° spermatocyte → spermatozoan → spermatid
Spermatogonium → 1 ° spermatocyte → 2 ° spermatocyte → spermatid → spermatozoan
Spermatogonium are diploid cells that differentiate into primary spermatocytes.
Spermatocyters undergo meiosis I to produce 2 haploid secondary spermatocytes.
secondary spermatocytes undergo meiosis II to become immature spermatids. Then they undergo maturation and become sperm, or spermatozoa.
Which of the following correctly pairs the stage of development of an egg cell with the relevant point in a woman’s life cycle?
From birth to menarche—prophase II
At ovulation—metaphase I
At ovulation—metaphase II
At fertilization—prophase II
At ovulation—metaphase II
From birth up until before ovulation, all egg cells are halted at prophase I of meiosis I. –> these are primary oocytes
At ovulation, cells complete meiosis I and halt at metaphase II of meiosis II as a haploid cell –> secondary oocyte
When a sperm cell penetrates the secondary oocyte, meiosis II completes to become a mature ovum
Some studies suggest that in patients with Alzheimer’s disease, there is a defect in the way the spindle apparatus attaches to the kinetochore fibers. At which stageof mitotic division would one first expect to be able to visualize this problem?
Prophase
Metaphase
Anaphase
Telophase
Prophase
The spindle aparatus (microtubules) interacts with kinetochore fibers at the end of Prophase. Then the microtubule spindle aparatus lines up the chromosomes at the equitorial plate during metaphase.
A researcher wishes to incorporate a radiolabeled deoxyadenine into the genome of one of the two daughter cells that would arise as a result of mitosis. What is the latest stage of cellular development during which the radiolabeled deoxyadenine could be added to achieve this result?
G 1
G 2
M
S
S
It needs to be inserted before DNA replication has been completed.
DNA replication occurs during the S stage so it can be incorporated during G1 (occurs before S) or the S stage.
Certain ovarian tumors called granulosa cell tumors are known to produce excessive levels of estrogen. A physician who diagnoses a granulosa cell tumor should look for a secondary cancer in which of the following parts of the reproductive tract?
Fallopian tube
Cervix
Endometrium
Vagina
Endometrium
Estrogen is known to cause the growth of the endometrial lining during the follicular phase of the menstrual cycle and its levels stay high during the luteal phase to promote vascularization in this tissue.
Upon ovulation, the oocyte is released into the:
fallopian tube.
follicle.
abdominal cavity.
uterus.
abdominal cavity.
Ovarian follicle releases the oocyte into the abdominal cavity. With the help of cilia, the oocyte is drawn into the fallopian tube and travels to the uterus.
If it gets fertilized in the fallopian tube, it will implant into the uterine wall.
If fertilization doesnt occur, it will be expelled along with the uterine lining during menstruation.
Which of the following INCORRECTLY pairs a structure of the male reproductive system with a feature of the structure?
Seminal vesicles—produce alkaline fructose-containing secretions
Epididymis—surrounded by muscle to raise and lower the testes
Vas deferens—tube connecting the epididymis to the ejaculatory duct
Cowper’s glands—produce a fluid to clear traces of urine in the urethra
Epididymis—surrounded by muscle to raise and lower the testes
The epididymis is the site of sperm maturation. It is here where sperm gain mobility and are stored until ejaculation.
It is the Vas Deferens that is surrounded by muscle that raises and lowers the testis to maintain a constant temperature suitable for sperm production
What is the last point in the meiotic cycle in which the cell has a diploid number of chromosomes?
During interphase
During telophase I
During interkinesis
During telophase II
During telophase I
Which of the following does NOT likely contribute to genetic variability?
Random fertilization of an egg by a sperm
Random segregation of homologous chromosomes
Crossing over between homologous chromosomes during meiosis
Replication of the DNA during S stage
Replication of the DNA during S stage
An individual who is phenotypically female is found to have only one copy of a disease-carrying recessive allele on the X chromosome, yet she demonstrates all of the classic symptoms of the disease. Geneticists determine she has a genotype that likely arose from nondisjunction in one of her parents. What is the likely genotype of this individual?
46,XX (46 chromosomes, with XX for sex chromosomes)
46,XY
45,X
47,XXY
45,X
Nondisjunction refers to the incorrect segregation of homologous chromosomes during anaphase I or of sister chromatids during anaphase II. In either case, one daughter cell ends up with 2 copies of related genetic material, while the other receives zero.
During which phase of the menstrual cycle does progesterone concentration peak?
Follicular phase
Ovulation
Luteal phase
Menses
Luteal phase
Progesterone peaks during the luteal phase - it supports the endometrium for potential implantation of a blastula.
Progesterone levels are low during follicular and ovulation.
