BSC 2086 FINAL EXAM COMPLETE QUESTIONS AND 100% CORRECT ANSWERS | VERIFIED EXAM QUESTIONS

BSC 2086 FINAL EXAM COMPLETE QUESTIONS AND 100% CORRECT ANSWERS | VERIFIED EXAM QUESTIONS .•Reproductive organs - ANSWERS-•Also secrete hormones that play major roles in the maintenance of normal sexual function .•Reproductive Structures - ANSWERS-•Gonads: are organs that produce gametes and hormones •Ducts: receive and transport gametes •Accessory glands: secrete fluids into ducts •Perineal structures collectively known as: external genitalia .•The Reproductive Tract - ANSWERS-•Includes all chambers and passageways that connect ducts to the exterior of the body .•Male and Female Reproductive Systems - ANSWERS-•Are functionally different •Female produces one gamete per month •Retains and nurtures zygote - formed after fertilization of egg by sperm cell •Male produces large quantities of gametes •Produces 1/2 billion sperm per day .•The Male Reproductive System - ANSWERS-•Testes or male gonads •Secrete male sex hormones (androgens) •Produce male gametes (spermatozoa or sperm) •Accessory organs - secrete fluids into ejaculatory ducts and urethra •Seminal glands (vesicles) •Prostate gland Bulbo-urethral glands .•Pathway of Spermatozoa - ANSWERS-•Testis (testes = plural) •Epididymis •Ductus deferens (vas deferens) •Ejaculatory duct •Urethra .•External Genitalia - ANSWERS-•Penis •Erectile organ contains distal portion of urethra •Scrotum - Encloses testes •Has two chambers or scrotal cavities •Each testis lies in a separate scrotal chamber •Raphe - raised thickening in scrotal surface •Marks partition of two scrotal chambers .•The Testes - ANSWERS-•Oval shaped •5 cm long, 3 cm wide, 2.5 cm thick (2 in. × 1.2 in. × 1 in.) •Each weighs 10-15 g (0.35-0.53 oz) •Hang in scrotum .The Dartos Muscl - ANSWERS-•Is a layer of smooth muscle in dermis of scrotum •Resting muscle tone causes characteristic wrinkling of scrotal surface, elevates testes .•The Cremaster Muscle - ANSWERS-•Is a layer of skeletal muscle deep to dermis, can contract or relax to move scrotum •Tenses scrotum and pulls testes closer to body - occurs during temperature regulation and sexual arousal Normal sperm development in testes require 1.1°C (2°F) temp. lower than body temp .•The Spermatic Cords - ANSWERS-•Extend between abdominopelvic cavity and testes •Consist of layers of fascia and muscle •Enclose ductus deferens, blood vessels, nerves, and lymphatic vessels of testes •Pass through inguinal canal •Are passageways through abdominal musculature •Form during development as testes descend into scrotum •Cryptochidism - testes do not descend into scrotum, remain in abdomen. May cause sterility, testicular cancer (10%). If surgically corrected before puberty, will produce viable sperm cells. .•Histology of the Testes - ANSWERS-•Septa subdivide testis into lobules •Lobules contain about 800 slender and tightly coiled seminiferous tubules •Produce sperm •Testis contains about 1/2 mile of tightly coiled seminiferous tubules •Form a loop connected to rete testis, a network of passageways •Efferent Ductules - Connect rete testis to epididymis .•Connective Tissue Capsules - ANSWERS-•Surround tubules •Areolar tissue fills spaces between tubules •Within those spaces, there are: •Blood vessels •Large interstitial cells (Leydig cells) •Produce androgens, dominant male sex hormones •Testosterone is the most important androgen .•Mitosis - ANSWERS-•Is part of somatic cell division - occurs in almost all cells in the body •Produces two diploid (2n) daughter cells Both have identical pairs of chromosomes .•Meiosis - ANSWERS-•Is a special form of cell division involved only in production of gametes - produces: •Spermatozoa in males •Oocytes in females •Gametes contain 23 chromosomes, half the normal amount •Fusion of male and female gametes produces zygote with 46 chromosomes •In males, occurs at seminiferous tubules: •Begins with primary spermatocytes •Produces spermatids (undifferentiated male gametes) •DNA duplicated before meiosis occurs (occurs in interphase) •Meiosis I - reductional division (since the chromosome number is halved from 46 to 23) •Prophase I •Chromosomes condense •Synapsis - Maternal & paternal chromosomes come together, forms a tetrad •Crossing over (exchange of genetic material that increases genetic variation among offspring) occurs •Metaphase I •Tetrads line up along metaphase plate .•Meiosis I - ANSWERS-•Anaphase I •Maternal and paternal chromosomes separate, each tetrad splits, maternal & paternal components are randomly distributed to the daughter cell •Telophase I •Ends with formation of two daughter cells with unique combinations of chromosomes •Both cells contain 23 chromosomes with two chromatids each (not the same as a diploid cell) •Interphase separates meiosis I and meiosis II •Is very brief, DNA is not replicated .Meiosis II - ANSWERS-•- equational division since chromosome number is not changed •Proceeds through prophase II and metaphase II •Anaphase II •Duplicate chromatids separate •Telophase II •Yields four cells, each containing 23 chromosomes (however cytoplasm may not be evenly distributed) .Note: DNA replication only occurs once and it happens before Meiosis I - ANSWERS-