Module 7: BIOD 103/ BIOD103 (NEW 2026/2027 COMPLETE UPDATE WITH VERIFIED SOLUTIONS) Medical Terminology | Questions & Answers | Grade A | 100% Correct – Portage Learning

…..DLDD Module 7: BIOD 103/ BIOD103 (NEW 2026/2027 COMPLETE UPDATE WITH VERIFIED SOLUTIONS) Medical Terminology | Questions & Answers | Grade A | 100% Correct – Portage Learning Q. Describe the contents of the scrotum and explain why the scrotum is outside of the abdominal cavity. The scrotum contains two testes with the epididymis. The scrotum hangs outside of the body to control the temperature within the scrotum. ANSWER Sperm are not viable at body temperature and need to be at a lower temperature. Q. The ____ are the cells within the testes that produce sperm. ANSWER seminiferous tubules Q. Describe the three columns of the penis. Which column contains the urethra? What is another name for the head of the penis? ANSWER The penis contains two columns, called corpora cavernosa penis, and the third column, called the corpus spongiosum. The corpus spongiosum contains the urethra. The head of the penis is also called the glans penis. Q. List the path of sperm from where it is formed to outside the body, including the three sections of the urethra. ANSWER Testes, epididymis, vas deferens, ejaculatory duct, and then the urethra. The three sections of the urethra are the prostatic urethra, the membranous urethra, and the penile urethra. Q. Describe the various structures that add to the seminal fluid prior to ejaculation. ANSWER The seminal vesicles secrete fluid that becomes part of the seminal fluid. The bulbourethral gland and the prostate gland secrete mucus and fluid that also become part of the seminal fluid. Q. The _(A)_ is the skin folds that cover the glans penis. It may be removed by a procedure called _(B)_. ANSWER A) foreskin B) circumcision Q. The _(A)_ are the primary female sex organs. They produce both _(B)_, the female sex cell, and _(C)_ and _(D)_, the female sex hormones. ANSWER A) ovaries B) the ova C) estrogen D) progesterone Q. Describe the sections of the uterus, the layers of the uterus, and the function of the uterus. ANSWER The sections of the uterus are the fundus, the body, and the cervix. The layers of the uterus are the endometrium, myometrium, and perimetrium. The function of the uterus is to house the developing fetus during pregnancy. It also functions to contract during childbirth to push the newborn out of the uterus. Q. Describe the structure and purpose of the fallopian tubes. Describe the function of the vagina. ANSWER The fallopian tubes have three sections: the infundibulum, the ampulla, and the isthmus. The function of the fallopian tubes is to collect an ovum after it has been released from the ovary and propel it towards the uterus. Fertilization frequently occurs in the fallopian tubes. The function of the vagina is to provide a way for menstrual fluid to leave the uterus, as well as serve as the birth canal for the fetus during childbirth. The vagina also receives the penis during sexual intercourse. Q. The external female genitalia is called the _(A)_. B) What are the sections of the female genitalia? ANSWER A) the vulva B) The sections of the vulva are the mons pubis, the labia majora and minora, the vestibule, and the clitoris. The vestibule contains the external urinary meatus and the ducts of the Bartholin glands. Q. Identify and describe the three phases of the menstrual cycle. ANSWER The follicular phase is first and this is when the endometrium is shed through the vagina. The ovulatory phase is next. The levels of estrogen, FSH, and LH rise, which causes the endometrium to thicken again and a follicle within the ovary to develop and then release a mature egg. The final phase is the luteal phase. The corpus luteum within the ovary secretes progesterone, and estrogen continues to develop the endometrium. If the egg is not fertilized, these hormone levels will decrease, and a new menstrual cycle will begin again. Q. How long is a typical pregnancy? What are the names of the three stages of human development? Describe the three stages of labor. ANSWER 40 weeks long The three stages of human development are the preembryonic stage, the embryonic stage, and the fetal stage. The first stage of labor is dilation of the cervix, the second stage of labor is the birth of the baby, and the third stage of labor is the delivery of the placenta. Q. The process of sperm formation occurs in the testicle, and they mature in the epididymis. Identify the terms from the flashcards that correspond to the following definitions. a. Pertaining to the testicle. b. Formation of sperm. c. Inflammation of the epididymis. ANSWER A) Testicular. B) Spermatogenesis. C) epididymitis. Q. A (heterosexual) couple is experiencing (infertility). A semen sample analysis is completed to look for (azoospermia) or (oligospermia). Define the underlined terms. ANSWER Heterosexual: Pertaining to the opposite sex; refers to a person whose sexual orientation is toward people of the opposite sex. Infertility: Inability of a heterosexual couple to produce viable offspring. Azoospermia: Condition in which the semen lacks sperm. Oligospermia: Condition where there is a scanty amount of sperm in the semen. Q. A man with a testicular mass presented to the surgeon to discuss removal of the mass. Identify and define two surgical terms related to the testes from the flashcards that may have been discussed. ANSWER Orchiectomy is the surgical excision of a testicle. Orchidotomy is a surgical incision into a testicle. Q. A common symptom of an STI is (balanitis) and the patient is instructed to avoid (coitus) until the symptom has resolved. A) Define the abbreviation, STI. B) Define the underlined words. ANSWER A) STI means sexually transmitted infection. B) Balanitis means inflammation of the glans penis. Coitus means sexual intercourse between a man and a woman. Q. A male athlete was taking steroids to improve his performance. He developed (gynecomastia) due to the excess steroid use. Define the underlined word. ANSWER Gynecomastia is the excessive development of the mammary glands in a male. Q. During an annual exam, a woman reports that she is using two types of (contraception): a condom and a (spermicide). Define the underlined words. ANSWER Contraception is the process of preventing conception or a pregnancy Spermicide is an agent that kills sperm A woman in her third trimester of pregnancy is sent for an emergent (cesarean section) surgery due to (abruptio placentae). Define the underlined words. Cesarean section is a surgical delivery of the fetus through an incision created in the abdominal cavity and the uterus. Abruptio placentae is an emergency condition where the placenta separates from the uterine wall prior to birth of the fetus. A 47-year-old woman presents to the (0gynecologist) to discuss an (endometrial ablation) due to (menorrhagia). Define the underlined terms. Gynecologist is a physician who specializes in the female reproductive system. Endometrial means pertaining to the endometrium, the innermost layer of the uterus. Ablation is a procedure that destroys the uterine lining. Menorrhagia is extensive menses, either in number of days or amount of blood. A woman presented to her physician because she had not had a period for 3 months. An ultrasound confirmed an intrauterine pregnancy and the physician documented Gravida-1 Para-0 in the patient's medical chart. A) What is a medical term that means a lack of the monthly menses? B) Define intrauterine. C) What does the documentation Gravida-1 Para-0 mean? A) Amenorrhea means a lack of the monthly menses. B) Intrauterine means within the uterus. C) Gravida is a term that means a pregnancy. Para refers to a woman who has given birth after 20 weeks gestation. Gradiva-1 Para-0 means that the patient has been pregnant once and has not yet given birth. A woman underwent a procedure with a (colposcope) due to an abnormal (pap smear). Define the underlined terms. Colposcope is a medical instrument that examines the cervix and vagina with a magnifying lens. Pap smear is a test that is used for early detection of cervical cancer where cells are removed from the cervix and then examined under a microscope. A patient underwent a balanoplasty to correct an epispadias deformity. A) Identify and define the combining form in balanoplasty and then define the term. B) Define epispadias. A) The combining form is balan/o, which means glans penis. The term balanoplasty is a surgical repair of the glans penis. B) Epispadias is a deformity where the urethral meatus opens on the dorsal side of the penis. A boy with bilateral (cryptorchism) underwent a surgical (orchiopexy). A) Identify and define the combining form in the underlined words. B) Using the definitions of these words, explain why the boy had this procedure performed. (Hint: The suffix -pexy means a surgical fixation) A) The combining form is orch/o meaning testicle. B) Both of the testicles did not descend into the scrotum, a condition called cryptorchism. He had a surgical procedure called an orchiopexy completed where the testes were freed and then implanted or fixed within the scrotum. During a vasectomy, the vas deferens are cut bilaterally to prevent sperm from leaving the body. Identify and define the combining form in the term, vasectomy. Vas/o is the combining form, and it means vessel. The fluid in the male (ejaculation) contains sperm and fluids secreted from the (seminal vesicles), (prostate) gland, and bulbourethral gland. Identify and define the combining forms in the underlined words. Ejaculat/o means to throw out. Semin/I means semen. Prostat/o means prostate. A pregnant woman underwent an amniocentesis as a part of her prenatal Identify and define the combining forms in the underlined words. Amni/o means amnion. Nat/o means birth. During labor, a woman had an episiotomy performed to allow the birth of the baby. Identify and define the combining form in the term episiotomy and then define the term. Episi/o means the vulva. An episiotomy is an incision in the vulva or external female genitalia. Specifically, an episiotomy is an incision in the vulva to prevent a laceration during delivery. A (postmenopausal) woman underwent a (hysterectomy) due to abnormal (uterine) Identify and define the combining forms in the underlined words. Men/o means menses. Hyster/o means the uterus. Uter/o means the uterus. It is recommended that a woman over the age of 40 have a yearly (mammography) study completed to screen for breast cancer. Identify and define the combining form in the underlined word and then define the term. Mamm/o means breast. Mammography is a study of the breast. Note: A mammogram report is the record produced by mammography. A male patient presented to the urologist because he has noticed a loss of force in his urine stream lately. The physician completed a DRE and felt an enlarged prostate gland. The physician ordered the blood test, PSA, as part of the screening for prostate cancer. Define the abbreviations. DRE is a digital rectal exam. PSA is the prostate-specific antigen A patient presented to the urologist because he was having difficulty maintaining an erection during sexual intercourse. During the interview, the patient stated that he recently underwent a TURP as treatment for an enlarged prostate. A) What is the abbreviation for this condition? B) What does the abbreviation TURP mean? A) The patient has ED, or erectile dysfunction. B) The abbreviation TURP means transurethral resection of the prostate, and it is a common surgical treatment for an enlarged prostate. A patient with gestational diabetes started biweekly outpatient NSTs to assess the FHR during the end of her pregnancy. Define the abbreviations. NST is a nonstress test. FHR is the fetal heart rate. A patient with a history of (HPV) presented to the (GYN) practice because she was experiencing lower abdominal pain. During the pelvic examination, the physician noted pain with cervical motion and adnexal tenderness. Additional (STI) testing was sent to support the diagnosis of (PID). A) Define the underlined abbreviations. B) Identify and define the combining form in the term cervical. C) What does the term adnexal tenderness refer to? A) HPV means human papillomavirus. GYN means gynecologist or gynecology. STI means sexually transmitted infection. PID means pelvic inflammatory disease. B) The combining form in the term cervical is cervic/o meaning cervix. C) Adnexal tenderness refers to tenderness where the ovaries and fallopian tubes are located. A G3P2 woman at 22 weeks gestation presents to the emergency room because she has been experiencing uterine cramping and bleeding. An ultrasound confirms cervical dilation and the presence of the products of conception within the uterus. A) Define the abbreviation G3P2. B) What type of abortion is this woman experiencing? A) G3P2 means that the woman has been pregnant 3 times and that she has given birth to two children. She is currently in her third pregnancy. B) She is experiencing an imminent or inevitable abortion, as she has uterine cramping and bleeding, dilation of the cervix, and the products of conception are still within the uterus. Which types of abortions may require a D&C procedure? What does the D&C abbreviation mean? Describe this procedure. An incomplete abortion and a missed abortion may require a D&C to remove the products of conception from the uterus. The D&C abbreviation means dilation and curettage. During this procedure, the cervix is manually dilated and the wall of the uterus is scraped to ensure that there are no remaining products of conception in the uterus, as these can be a source of infection and bleeding. What is an extrauterine pregnancy? Where do they commonly occur? What is the name of the surgical procedure that may be necessary to address this condition? An extrauterine pregnancy is a fertilized egg that implants in a place other than the uterus. They commonly occur in the fallopian tube, but they can implant in the ovary, cervix, or abdominal cavity. If the ectopic pregnancy occurs in the fallopian tube, a salpingectomy may need to be performed. This is the removal of the fallopian tube. An ectopic pregnancy was diagnosed by evidence of an ___ ___ seen on an ultrasound. adenal mass A woman with the symptoms of dysmenorrhea, chronic pelvic pain, and dyspareunia may be diagnosed with endometriosis. A) Identify and define the prefix, combining form, and suffix in the term endometriosis. B) What occurs in this condition? A) The prefix is endo- meaning within, the combining form is metr/o meaning the womb or uterus, and the suffix is -osis meaning condition of. B) Endometriosis is a condition where endometrial tissue grows outside the uterus. What is the most common benign tumor of the female reproductive tract? What is the name of the surgery that would remove this type of tumor? The most common benign tumor of the female reproductive tract is a uterine fibroid. The name of a surgery that would remove this type of tumor is a myomectomy. Describe the urinary symptoms a man may experience if he has BPH. Obstructive urinary complaints include a feeling of hesitancy prior to initiating urination, a decrease in the force of urination, a sensation of incomplete bladder emptying, straining to urinate, and post-void dribbling. Irritative symptoms are urgency, frequency, and nocturia. What is the most common cause of erectile dysfunction? vascular disease that obstructs the flow of blood to the penis Describe a general characteristic of STIs that make it difficult to stop the infection from spreading. STIs have a latent period where the patient has an active infection but does not show symptoms of the infection. The main organs of the male reproductive tract include the testes, epididymis, vas deferens, and urethra The accessory glands are the bulbourethral glands, prostate gland, and seminal vesicles The scrotum also contains the epididymis, which connects the testes with the rest of the male reproductive system The internal organs of the male reproductive tract include the epididymis, the vas deferens, seminal vesicles, bulbourethral gland, and the prostate gland The epididymis is is/located/function? a coiled tube that is located on the top of each testis It is connected to the testis and functions as the location where sperm mature The vas deferens is a continuation of the ______ and carries sperm where? epididymis and carries the sperm from the epididymis, out of the scrotum, into the abdominal cavity through the inguinal ring, and ends at the ejaculatory duct The ejaculatory duct connects the vas deferens to the urethra in the prostate gland The two glands in the male reproductive tract are the/function to? The bulbourethral glands secrete mucus before ejaculation. The prostate gland secretes fluid that helps the sperm remain viable. The most common STIs are chlamydia, genital warts, gonorrhea, and herpes genitalis. HIV, syphilis, and hepatitis B Chlamydia is caused by what bacteria? Symptoms in men/women? bacteria chlamydia trachomatis In men, symptoms include discharge from the penis, burning and itching in the genital area, dysuria, and swollen testes. In women, chlamydia can cause symptoms of vaginal discharge, cystitis, pelvic pain, and cervicitis. Chlamydia complications/treatment? Complications of untreated chlamydia include pelvic inflammatory disease in women and sterility in both men and women. This infection is treated with an antibiotic and is reported to the public health authorities in the United States. Gonorrhea caused by what bacteria and what symptoms in men/women? Neisseria gonorrhoeae Symptoms include vaginal and urethral discharge, dysuria, and urinary frequency Gonorrhea complications and treatment? This infection can also lead to pelvic inflammatory disease and sterility in women. This infection is treated with an antibiotic. Genital warts is caused by and what symptoms in men/women? human papillomavirus (HPV) This virus causes cauliflower-like growths on the penis and perianal area in men and around the vagina and perianal area in women. Genital warts complication/treatment? HPV is also the cause of some vaginal and vulvar cancers in women. Genital warts are treated with laser surgery, chemotherapy, cryosurgery, and cauterization. Infection from four types of this virus can also be prevented with a vaccine called Gardasil. Herpes genitalis is caused by and what symptoms for men/women? herpes simplex virus 2 This infection typically causes fluid-filled blisters on the penis and around the vaginal area. Patients will also have general flu-like symptoms including fever, headache, malaise, anorexia, and muscular pain. Herpes genitalis treatment/cure? There is not a cure for this infection and patients will have times of active symptoms and times where the virus is latent. Patients are treated with anti-viral medications that can relieve the symptoms of pain and itching during acute outbreaks. Herpes simplex is a viral infection caused by the herpes virus type 1, and it usually causes blisters around the lips and the nose that are painful Benign prostatic hyperplasia (BPH) is an enlargement of the prostate gland. This is a common condition that occurs as a man ages BPH diagnostic tools: DRE, UA, BPH treatment: Medications such as alpha-blockers, which relax the neck of the bladder, and 5-alpha reductase inhibitors, which decrease the body's ability to make testosterone, can ease voiding symptoms and decrease the size of the prostate. There also are several minimally invasive surgical options available to destroy parts of the prostate and relieve symptoms. ED can be caused by neurogenic or hormonal conditions, complications of diabetes mellitus, several prescription drugs, and substance abuse ED treatment: This condition can be treated with oral medications, medications that are injected at the base of the penis, a vacuum erection device, or surgical implantation of a penile prosthesis. The key organs of the female reproductive system are the ovaries, fallopian tubes, uterus, vagina, and breasts The normal positioning of the uterus is called anteflexion The ovarian end of the fallopian tube is called the infundibulum The opening of the fallopian tube is called the ostium The ostium is surrounded by tiny finger-like structures called fimbriae Moving towards the uterus, the middle section of the tube is called the ampulla The section that attaches to the uterus is called the isthmus Fertilization, also called conception, is when an ovum joins with a sperm cell to form a zygote The vestibule is the opening to the vagina that also contains the opening of the urethra and the excretory ducts of the Bartholin glands After childbirth, the hormone prolactin is produced by the anterior pituitary gland. This hormone stimulates the mammary glands to produce milk. Colostrum is the milk that is immediately produced after childbirth. Mature breast milk is produced 2-3 days after childbirth and is the best food available to the newborn infant Babies can survive on their mother's milk exclusively for up to 6 months after birth Active labor has three stages: The first stage is the dilation stage where the cervix thins and dilates to allow the baby to pass through. The second stage is expulsion, which is the time from when the cervix is fully dilated to the actual delivery of the baby. The third stage is the placental stage, which is the delivery of the placenta. A missed abortion is when the fetus dies but there are no symptoms to indicate that the fetus is no longer viable A complete abortion occurs when all the products of conception are completely expelled An incomplete abortion occurs when some of the products of conception remain in the uterus When the cervix does not dilate but there is bleeding or cramping, this is referred to as a threatened abortion An inevitable or imminent abortion is when there is bleeding, cramping, cervical dilation, and rupture of membranes but the embryo has not yet passed out of the uterus List three other sexually transmitted infections herpes HIV, syphilis, and hepatitis B. Errors in DNA replication can come from DNA polymerase. DNA Pol III catalyzes the addition of successive nucleotides to the 5' end of a growing polynucleotide chain. False From the DNA X-ray crystallography data, Franklin and Wilkins inferred that ____, while Watson and Crick determined that ____. the flat nucleotide bases are stacked upon each other; DNA is helical. The two molecules that alternate to form the backbone of a polynucleotide chain are sugar and phosphate. When a mutation occurs during DNA replication, ____ replaces the incorrect nucleotide with the correct one after the mismatched nucleotide has been removed. DNA polymerase If you consider a DNA molecule to resemble a twisted ladder, the rungs of the ladder are paired nitrogen bases. True In mismatch repair, enzymes remove incorrectly-paired nucleotides. True Short, noncoding, guanine-rich DNA sequences found at the ends of chromosomes are called telomeres. True ____, the ends of eukaryotic chromosomes, shorten with every cell division. Telomeres Because a newly synthesized DNA molecule contains ____, the replication process is said to be semiconservative. one parental strand and one new strand The information encoded by the DNA is specified by the nucleotide sequence of the DNA molecule. Enzymes called ____ form breaks in the DNA molecules to prevent the formation of knots in the DNA helix during replication. topoisomerases The DNA strand that is replicated smoothly and continuously is called the leading strand. A nucleotide is made up of a phosphate group, a five-carbon sugar molecule, and one of four nitrogeneous bases. What are special enzymes that recognize and remove the incorrectly paired nucleotides in DNA? Mismatch repair A mutation that replaces one amino acid in a protein with another is called a ____ mutation. missense Proteins synthesized in bacteria have which of the following at their amino terminal end? N-formyl-methionine Refer to the accompanying figure. Which label indicates the location of the promoter region? E If an mRNA transcript of the human XYZ gene was introduced into a yeast cell, the transcript would be: translated into the human XYZ protein. What conclusion was associated with mutant strain III in the accompanying figure? It was missing the enzyme that catalyzes the conversion of citrulline to arginine. The 3′ end of eukaryotic pre-mRNAs is changed by: adding 100−250 adenine nucleotides The molecule that connects a growing polypeptide chain and mRNA is called: tRNA. One of the mRNA codons specifying the amino acid leucine is 5′-CUA-3′. Its corresponding anticodon is: 3′-GAU-5′ A ribosome has one binding site for mRNA and two binding sites for tRNAs. False In the process of transcription, incoming RNA nucleotides are in their triphosphates form. True In the Beadle and Tatum study, it was important that Neurospora was haploid because: a mutation that arises is not masked by a normal allele on a homologous chromosome. A polyribosome is: a complex composed of several ribosomes and plus an mRNA transcript The template DNA strand is described as being parallel to the complementary RNA strand. False tRNA molecules are able to act as adapters between amino acids and mRNA during translation because: tRNA can bind to both mRNA and an amino acid. Aminoacyl-tRNA synthetases link ____ to their respective tRNA molecules by ____ bonds. codons; covalent Single-strand binding proteins prevent the hydrolysis of single-strand regions of DNA by nucleases. True DNA synthesis occurs only once during each cell generation. Alfred Hershey's and Martha Chase's experiments with bacteriophages showed that DNA was injected into bacteria. How is a bacterial chromosome replicated? The circular DNA molecule is replicated from one origin of replication bidirectionally. How are eukaryotic chromosomes replicated? The linear DNA molecules are replicated from multiple origins of replication bidirectionally. X-ray diffraction images produced by ____ were used by Watson and Crick to infer the structure of DNA. Franklin In one strand of a DNA molecule, adjacent nucleotides are joined by a phosphodiester linkage. True _____ bonds link the sugar and phosphate groups in the backbone of DNA molecules. Covalent phosphodiester Which of the following consists of short, noncoding, guanine-rich DNA sequences that repeat many times? Telomere Who first confirmed that the replication of DNA was semiconservative? Meselson and Stahl Why does DNA synthesis proceed in a 5′ to 3′ direction? DNA polymerases can only add nucleotides to the 3′ end of a polynucleotide strand. If DNA replication rejoined the two parental strands, it would be described as conservative RNA is ____ and contains the nitrogenous base ____, which is absent in DNA. single stranded; uracil The process in which RNA is synthesized using a DNA template is called translation. False Signal-recognition particle RNA is involved in directing the ribosome-mRNA-polypeptide complex to the rough ER. True snRNPs function to splice introns together. False The total number of different three-base combinations of the four nucleic acid bases is: 64 The process illustrated in the accompanying figure is: transcription Neurospora is an ideal organism to study the effects of genetic mutations because of several reasons. What is one of these? Neurospora mutant strains that cannot make a particular amino acid can still grow if that amino acid is added to the growth medium. Frameshift mutations result from the: insertion or deletion of one or two base pairs In the accompanying figure, the portion of the molecule containing the anticodon is indicated by the label: 3 Molecular chaperones assist in the folding of newly synthesized mRNAs. False A sequence of bases located upstream from a reference point occurs toward the: 5′ end of the mRNA sequence Binding of the appropriate aminoacyl-tRNA to the A site requires: energy supplied by GTP Beadle and Tatum irradiated Neurospora and initially grew the mutant strains on complete medium. How were they able to determine the type of mutation for each strain? By growing the mold on minimal media supplemented with different combinations of amino acids and vitamins Linus Pauling proposed the one gene - one enzyme hypothesis. False Which of the following causes the unwinding of the DNA double helix? DNA helicase The first scientists to use Griffith's transformation assay to identify genetic material were Avery, MacLeod, and McCarty. How many different kinds of amino acids are known? More than 20 Okazaki fragments are joined together by DNA ligase. Which of the following statements concerning DNA is FALSE? The sugar present in DNA is ribose. Linus Pauling demonstrated that: the structure of hemoglobin was altered by a mutation of a single gene. During translocation, the movement of the ribosome repositions the tRNA linked to the growing polypeptide chain to the ____ site, thereby vacating the ____ site for the arrival of a new amino-acyl tRNA. P; A Ribose differs from deoxyribose by having: an extra hydroxyl group RNA polymerase binds to the promoter sequence in RNA. False Uracil forms a complementary pair with ____ in RNA and ____ in DNA. adenine; adenine Beadle and Tatum began their studies with wild-type Neurospora. How is this organism best characterized? A normal phenotype that will grow on minimal medium helps to deliver the ribosome-mRNA-polypeptide complex to the rough ER SRP RNA small double-stranded RNA molecules; regulates gene expression miRNA siRNA small RNA molecules; inhibits mobile DNA element activity in germ cells piRNA small RNA molecules; inhibit translation miRNA responsible for pre-rRNA molecule processing in the nucleolus snoRNA large RNA molecules; regulates chromatin structure lncRNA Retroviruses, such as RNA tumor viruses, use __________ to make DNA from their RNA genomes. reverse transcriptase How does the first nucleotide at the 5′ end of a new mRNA chain differ from the other nucleotides in the chain? The first nucleotide retains its triphosphate group, while the others do not. The experimental design in the accompanying figure was used to examine: the relationship between genetic changes and metabolic enzymes. In DNA replication, the lagging strand is synthesized as a series of Okazaki fragments Which is a powerful method for determining the 3D structure of a molecule? X-ray diffraction According to Chargaff's rules, the adenine content in any DNA molecule is always equal to the thymine content. Primase is the enzyme responsible for making short strands of RNA at the site of replication initiation. discovered that DNA was responsible for bacterial transformation Avery demonstrated that genetic traits can be transferred from one bacterium to another Griffith discovered that the genetic material in bacteriophages is DNA Hershey and Chase used proteins labeled with 35S and DNA labeled with 32P to demonstrate that viral DNA entered bacterial cells, but viral proteins did not Hershey and Chase demonstrated the ratio of nucleotide bases in DNA Chargaff demonstrated that DNA is replicated semiconservatively Meselson and Stahl grew bacteria in the presence of heavy nitrogen (15N), followed by growth in 14N medium for one or two generations, then measured the density of the DNA Meselson and Stahl X-ray diffraction studies are used to determine the distances between atoms of molecules. Unlike normal cells, cancerous cells can maintain telomere length as they divide. Initiation of transcription requires: a promoter sequence How is the four-letter language of nucleic acids converted into the 20-word language of amino acids? The four nucleic acid bases combine in three-letter sequences that define different amino acids. A ____ mutation results in the conversion of a codon specifying an amino acid to a termination codon. nonsense Following peptide bond formation between the amino acid in the A site on the ribosome and the growing polypeptide chain, the tRNA in the A site: moves to the P site of the ribosome What conclusions did Beadle and Tatum reach in their studies of Neurospora? Each mutant gene affected only one enzyme. Peptidyl transferase, a _____ molecule, catalyzes the formation of _____ between amino acids at the P and A sites. ribozyme; peptide bonds In eukaryotes, the initiator tRNA carries the amino acid leucine. False What allows each strand of DNA to serve as a template for a new DNA strand during replication? Complementary base pairing between purines and pyrimidines on opposite strands The ends of eukaryotic chromosomes can be lengthened by telomerase Hydrogen bonds can form between guanine and ____, and between adenine and ____. cytosine; thymine In the experiments of Griffith, the conversion of nonlethal R-strain bacteria to lethal S-strain bacteria was due to transformation. What are the small circular DNA molecules that carry genes separate from those on a bacterial chromosome? Plasmids The enzyme peptidyl transferase catalyzes peptide bond formation during the elongation stage of translation. True Leader sequences contain signals that: allow the ribosomes to be properly positioned for translation of mRNA molecules. The wobble hypothesis states that: certain tRNA anticodons can pair with more than one codon sequence. A "5′ cap": protects mRNA from degradation. Mobile genetic elements, such as transposons and retrotransposons, are significant because: mutations caused by retrotransposons contribute greatly to a species' evolution. The notion that the genetic code is universal suggests a common ancestor for all living organisms. True One of the pyrimidine bases in a DNA molecule is adenine. False In replication, once the DNA strands have been separated, reformation of the double helix is prevented by single-strand binding proteins. Which of the following nucleotide sequences represents the complement to the DNA strand, 5′-AGATCCG-3′? 3′-TCTAGGC-5′ Alfred Hershey's and Martha Chase's experiments with bacteriophages showed that DNA was injected into bacteria. A(n) nonsense mutation is a base-pair substitution that results in the replacement of one amino acid with another. False During protein synthesis, ribosomes: attach to the mRNA molecule and travel along its length to produce a polypeptide Which of the following is a characteristic of uracil? It has the ability to bond with adenine. Individuals with mutations in excision repair enzymes may suffer from ____ due to unrepaired DNA damage caused by ____. skin cancer; the sun's UV rays The process of DNA replication is conservative. False What happened in an experiment where normal cultured human cells were infected with a virus that carried DNA encoding for the telomerase catalytic subunit? The cells underwent more cell divisions than normal. Replication typically occurs at a single origin of replication in eukaryotic chromosomes. False An RNA primer is synthesized by RNA primase. False What happens during nucleotide excision repair? A nuclease removes the damaged DNA. These noncoding sequences located within coding regions of ____ genes are called ____. only eukaryotic; introns Which of the following statements is FALSE with regard to DNA replication? The strand being copied is read in the 5¢-3¢ direction. The two strands of a DNA double helix can be described as running parallel to each other. False What is the modern definition of a gene? a DNA sequence that encodes a specific RNA or protein product RNA synthesis is also known as: transcription Translation is initiated at the ____. AUG codon A(n) transposon is a DNA sequence that "jumps" into the middle of a gene. True Introns in pre-mRNA: are spliced out of the message. One function of snoRNAs is to process pre-rRNA molecules in the mitochondrion. False Okazaki fragments are complementary to the leading strand of DNA. False Why is DNA able to store large amounts of information? Its nucleotides can be arranged in many possible sequences. Adenine and thymine are held together by two hydrogen bonds in a double stranded DNA molecule. True A grouping of three nucleotides codes for one amino acid. True the first stage of translation initiation protein synthesis proceeding in a 5' to 3' direction elongation triggered by a stop codon termination completed polypeptide chain released from ribosome termination growth of the polypeptide chain elongation assembly of the ribosome initiation initiator tRNA binds to the start codon initiation Why is only one strand of DNA transcribed into mRNA? Because transcribing both DNA strands would produce different amino acid sequences RNA interference is a process by which noncoding RNA molecules regulate gene expression. True catalyzes formation of sugar-phosphate bonds in adjacent Okazaki fragments DNA ligase produces breaks in the DNA molecules and then rejoins the strands to prevent supercoiling Topoisomerase joins successive nucleotides to a growing polynucleotide strand, complementary to the template strand DNA polymerase catalyzes the synthesis of an RNA primer at both leading and lagging strand DNA primase prevents formation of hydrogen bonds between complementary base pairs Single-strand binding protein opens the double helix like a zipper DNA helices prevents the hydrolysis of single DNA strands by nucleases Single-strand binding protein binds DNA at the origin of replication and breaks the hydrogen bonds between the paired bases DNA helicase adds nucleotides only to the 3¢ end of an existing polynucleotide strand DNA polymerase catalyzes a reaction that occurs in the lagging strand but not in the leading strand DNA ligase Viruses that infect bacteria are known as? Bacteriophages The poly-A tail is thought to facilitate the export of mRNA from the nucleus. True Refer to the accompanying figure. The component labeled as B is: RNA polymerase. Reverse transcriptase catalyzes the synthesis of DNA from an RNA template. True Garrod first proposed that: metabolic defects were due to the lack of an enzyme.