Khan Academy Biology: Chapter 2 Questions

Which cells and their specific cell adhesion structures prevent antibodies from binding with sperm? A. Sertoli cells' tight junctions B. Interstitial cells' desmosomes C. Spermatocyte's tight junctions D. Spermatogonia's gap junctions

A. Sertoli cells' tight junctions

During which phase does the nuclear envelope begin to disappear? A. Cytokinesis B. S phase C. Prometaphase D. Anaphase

C. Prometaphase

Colchicine is a drug used to treat gout. It also happens to arrest cells in anaphase. Which cytoskeletal protein does colchicine effect? A. Actin B. Keratin C. Tubulin D. Myosin

C. Tubulin

What would NOT be a side effect of a drug that hypo-stimulates the Leydig (interstitial) cells on a pubertal human? A. Increased secretion of LH (luteinizing hormone) by anterior pituitary B. Increased secretion of FSH (follicle stimulating hormone) by anterior pituitary C. Increased secretion of GnRH (gonadotropin-releasing hormone) by hypothalamus D. Decreased secretion of GnRH (gonadotropin-releasing hormone) by hypothalamus

D. Decreased secretion of GnRH (gonadotropin-releasing hormone) by hypothalamus

During pregnancy hormones are responsible for maintaining pregnancy. What kind of hormonal imbalances can lead to miscarriages during pregnancy? A. Decreasing levels of oxytocin B. Stimulation of progesterone secretory tissues C. Increasing levels of estrogen D. Early degeneration of corpus luteum

D. Early degeneration of corpus luteum

Oogenesis, the process that creates female gametes, is halted at prophase I until puberty. Which of the following describes the DNA content of a female's gametes during her childhood? A. 46 chromosomes, 92 chromatids B. 23 chromosomes, 46 chromatids C. 46 chromosomes, 46 chromatids D. 23 chromosomes, 23 chromatids

A. 46 chromosomes, 92 chromatids

Which statement best describes chromosomal movement during mitosis? A. Centrioles send out microtubules, which bind to kinetochores to pull chromatids apart. B. Centrioles on chromatids bind kinetochores to rays sent by the asters. C. Each centrosome binds an individual chromatid to ensure equal division. D. Microtubules bind tubulin polymers on centromeres to initiate homologous chromosome separation.

A. Centrioles send out microtubules, which bind to kinetochores to pull chromatids apart.

Which penile tissues remain pliable during an erection? Which tissues become firm? What is the function of the pliable tissues? A. Corpus spongiosum; corpora cavernosa; maintain the urethra open B. Corpora cavernosa; corpus spongiosum; contract the testis during ejaculation. C. Corpus spongiosum; corpora cavernosa; sustain the erection. D. Corpora cavernosa; corpus spongiosum; secrete seminal fluid.

A. Corpus spongiosum; corpora cavernosa; maintain the urethra open

Which impairment in the male reproductive system will NOT necessarily lead to sterility? A. Obstruction of bulbourethral glands B. Blockage of the ampulla of vas deferens C. Degeneration of epididymis D. Prostatic cancer

A. Obstruction of bulbourethral glands Bulbourethral glands produce pre-ejaculatory fluid that aids in lubrication, thus its obstruction does not interfere with sperm production, maturation, or activation

Oogenesis and spermatogenesis describe the process of meiosis in females and males respectively. What statement about the two processes is true? A. Oogenesis produces a larger gamete than spermatogenesis B. Oogenesis forms two polar bodies while spermatogenesis only forms one C. Both are halted in an intermediate step until puberty D. Both produce the same number of viable gametes

A. Oogenesis produces a larger gamete than spermatogenesis

What is the correct trajectory of sperm from site of seminiferous tubules to spongy urethra? A. Straight tubules, rete testis, efferent ductules, epididymis ductus, vas deferens, ejaculatory duct, prostatic urethra, membranous urethra B. Rete testis, straight tubules, efferent ductules, vas deferens, epididymis ductus, ejaculatory duct, membranous urethra, prostatic urethra C. Rete testis, efferent ductules, straight tubules, vas deferens, epididymis ductus, ejaculatory duct, prostatic urethra, membranous urethra D. Straight tubules, efferent ductules, straight tubules, vas deferens, epididymis ductus, ejaculatory duct, prostatic urethra, membranous urethra

A. Straight tubules, rete testis, efferent ductules, epididymis ductus, vas deferens, ejaculatory duct, prostatic urethra, membranous urethra

How many chromatids and chromosomes should one expect to find in a secondary spermatocyte in a human? A. 92 chromatids, 46 chromosomes B. 46 chromatids, 23 chromosomes C. 23 chromatids, 23 chromosomes D. 46 chromatids, 46 chromosomes

B. 46 chromatids, 23 chromosomes Secondary spermatocyte is haploid

Which structures are responsible for maintaining levels of estrogen earlier and later in pregnancy? A. Placenta earlier and umbilical cord later B. Corpus luteum earlier and placenta later C. Placenta earlier and ovaries later D. Uterus earlier and ovaries later

B. Corpus luteum earlier and placenta later

Which hormonal change is linked with the menses period of uterine cycle? A. Increased secretion of progesterone by the corpus luteum B. Decreased levels of progesterone and estrogen C. Increased secretion of estrogen D. Increased levels of follicle stimulating hormone and luteinizing hormone

B. Decreased levels of progesterone and estrogen

What is the correct trajectory of sperm during ejaculation? A. Epididymis, ejaculatory duct, ampulla of vas deferens, vas deferens, urethra B. Epididymis, vas deferens, ampulla of vas deferens, ejaculatory duct, urethra C. Ejaculatory duct, epididymis, vas deferens, ampulla of vas deferens, urethra D. Vas deferens, ejaculatory duct, ampulla of vas deferens, urethra

B. Epididymis, vas deferens, ampulla of vas deferens, ejaculatory duct, urethra

Which structure is likely to be immediately affected due to spread of an infection in the cervical canal? A. Fallopian tube B. Fornix C. Clitoris D. Fimbriae

B. Fornix

Which of the following is not a reason cancer is hard to treat? A. Increased growth rate B. Increased contact inhibition C. Increased metastasis D. Increased mutation rate

B. Increased contact inhibition Contact inhibition in cells is a growth control mechanism that is often damaged or turned off in cancerous growths.

Retinoblastoma protein, RB, is an important cell cycle checkpoint protein that prevents the transition from G1 to S phase. The presence of the cyclin/CDK complex releases it from the genes that it binds. Which of the following mutation scenarios is least likely to lead to the formation of a neoplasm? A. Loss of functional RB and CDK that does not respond to negative feedback B. No RB mutation and CDK that cannot bind to cyclin C. Loss of functional RB and no CDK mutation D. No RB mutation and CDK that does not respond to negative feedback

B. No RB mutation and CDK that cannot bind to cyclin

Which hormonal supplementation therapy is the least likely to assist a female that has difficulties ovulating? A. Follicle stimulating hormone B. Progesterone C. Luteinizing hormone D. Estrogen

B. Progesterone

Which hormone is consistently positively correlated with thickening of the endometrium? A. Luteinizing hormone B. Progesterone C. Follicle-stimulating hormone D. Estrogen

B. Progesterone

What would be a direct result of an enzymatic deficiency on the acrosome? A. Implantation may occur in uterine tube B. Primary spermatocyte would not become secondary spermatocyte C. Egg would not complete metaphase II D. Spermatid would not become primary spermatocyte

C. Egg would not complete metaphase II Acrosome is responsible for sperm penetration in the egg, if that does not occur the egg would not complete metaphase II.

A karyotype can be used to check for certain chromosomal mutations. In what cell cycle phase can cells be karyotyped? A. Go B. Prophase C. Metaphase D. S

C. Metaphase Chromosomes do not condense until Prophase

Centrioles can be found in: A. In eukaryotic cells and in prokaryotic cells undergoing genetic recombination B. Only prokaryotic cells C. Only eukaryotic cells D. Both eukaryotic and prokaryotic cells

C. Only eukaryotic cells

During human meiosis and fertilization which cells are diploid? A. oogonia, spermatid, egg. B. Secondary oocyte, secondary spermatocyte, second polar body. C. Primary spermatocyte, primary oocyte, and zygote. D. Secondary polar body, embryo, spermatogonia.

C. Primary spermatocyte, primary oocyte, and zygote.

In humans, which meiotic phase has the longest duration? A. Anaphase I in females B. Prophase II in males C. Prophase I in females D. Metaphase II in females

C. Prophase I in females Female gamete formation starts at birth, but the gametes remain arrested in meiosis I until ovulation occurs.

Which of the following would you expect to see in a cancerous mass? A. Decreased ATP use B. Increased time in G0 C. Gain of function mutations in checkpoint proteins D. Loss of function mutations in apoptosis-controlling proteins

D. Loss of function mutations in apoptosis-controlling proteins

What is spermiogenesis? A. The process of meiosis in males. B. Selection of spermatogonia to become sperm. C. A process happening in the spermatic cord. D. Shedding of unnecessary cytoplasm.

D. Shedding of unnecessary cytoplasm. Spermiogeneis is the MATURATION of sperm