- Week 1 Introduction and gametogenesis and fertilization test of week 1
- Week 2 First week and second week of development： Cleavage to implantation Test for week 2
- Week 3 Third to eighth week of development： Gastrulation and differentiation of trilaminar disc Tes
- Week 4 Fetal membrane and placenta Test for week 4
- Week 5 Development of the head and neck Test for week 5
- Week 6 Development of the digestive and respiratory system Test for week 6
- Week 7 Development of urogenital system Test for week 7
- Week 8 Development of cardiovascular system Test for week 8
1、 问题:Which of the following is a major characteristic of meiosis I?
A:Splitting of the centromere
B:Pairing of homologous chromosomes
C:Reducing the amount of DNA to IN
D:Achieving the diploid number of chromosomes
答案: 【Pairing of homologous chromosomes】
2、 问题:A normal somatic cell contains a total of 46 chromosomes.What is the normal complement of chromosomes found in a sperm?
A:22 autosomes plus a sex chrom osome
B:23 autosomes plus a sex chromosome
答案: 【22 autosomes plus a sex chrom osome】
3、 问题:Which of the following describes the number of chromosomes and amount of DNA in a gamete?
答案: 【23 chromosomes,1N】
4、 问题:Which of the following chromosome compositions in a sperm normally results in the production of a genetic female if fertilization occurs?
A: 23 homologous pairs of chromosomes
B: 23 autosomes plus an X chromosome
C:22 autosomes plus a Y chromosome
D:22 autosomes plus an X chromosome
答案: 【22 autosomes plus an X chromosome】
5、 问题:In the process of meiosis,DNA replication of each chromosome occurs,form ing a structure consisting of two sister chromatids attached to a single centromere.What is this structure?
A:A duplicated chromosome
C:A synapsed chromosome
D:A crossover chromosome
答案: 【A duplicated chromosome】
6、 问题:All primary oocytes are formed by
A:week 4 of embryonic life
B: month 5 of fetal life
答案: 【 month 5 of fetal life】
7、 问题:When does formation of primary spermatocytes begin?
A:During month 5 of fetal life
C:During month 5 of infancy
答案: 【At puberty】
8、 问题:In the production of female gametes,which of the following cells can remain dormant for 12 to 40 years?
A:Primordial germ cell
D:First polar body
答案: 【Primary oocyte】
9、 问题:In the production of male gametes,which of the following cells remains dormant for 12 years?
A:Primordial germ cell
答案: 【Primordial germ cell】
10、 问题:Approximately how many sperm will be ejaculated by a normal fertile male during sexual intercourse?
答案: 【350 million】
11、 问题:A young woman enters puberty with approximately 40,000 primary oocytes in her ovary.About how many of these primary oocytes will be ovulated over the entire reproductive life of the woman?
12、 问题:How much DNA does a primary spermatocyte contain?
13、 问题:During ovulation,the secondary oocyte resides at what specific stage of meiosis?
A:Prophase of meiosis I
B:Prophase of meiosis II
C:Metaphase of meiosis I
D: Metaphase of meiosis II
答案: 【 Metaphase of meiosis II】
14、 问题:Concerning maturation of the female gamete(oogenesis),when do the oogonia enter meiosis I and undergo DNA replication to form primary oocytes?
A:During fetal life
D:With each ovarian cycle
答案: 【During fetal life】
15、 问题:Where do primordial germ cells initially develop?
A:In the gonads at week 4 of embryonic development
B:In the yolk sac at week 4 of embryonic development
C: In the gonads at month 5 of embryonic development
D:In the gonads at puberty
答案: 【In the yolk sac at week 4 of embryonic development】
1、 问题:A 20-year-old woman presents at the emergency department with severe abdominal pain on the right side with signs of internal bleeding. She indicated that she has been sexually active without contraception and missed her last menstrual period. Based on this information, which of the following disorders must be included as an option in the diagnosis?
D:Ectopic tubal pregnancy
答案: 【Ectopic tubal pregnancy】
2、 问题:When does a secondary oocyte complete its second meiotic division to become a mature ovum?
答案: 【At fertilization】
3、 问题:How soon after fertilization occurs within the uterine tube does the blastocyst begin implantation?
A:By 12 hours
B:By day 1
C:By day 2
D:By day 7
答案: 【By day 7】
4、 问题:Where does the blastocyst normally implant?
A:Functional layer of the endometrium
B:Basal layer of the endometrium
答案: 【Functional layer of the endometrium】
5、 问题:Which of the following events is involved in the cleavage of the zygote during week 1 of development?
A:Production of highly differentiated blastomeres
B:An increased cytoplasmic content of blastomeres
C:An increase in size of blastomeres
D:A decrease in size of blastomeres
答案: 【A decrease in size of blastomeres】
6、 问题:Which of the following structures must degenerate for blastocyst implantation to occur?
A:Endometrium in progestational phase
答案: 【Zona pellucida】
7、 问题: Individual blastomeres were isolated from a blastula at the 4-cell stage. Each blastomere was cultured in vitro to the blastocyst stage and individually implanted into four pseudopregnant foster mothers. Which of the following would you expect to observe 9 months later?
A:Birth of one baby
B:Birth of four genetically different babies
C:Birth of four genetically identical babies
D:Birth of four grotesquely deformed babies
答案: 【Birth of four genetically identical babies】
8、 问题: In oogenesis, which of the following events occurs immediately following the completions of a meiosis II?
A:Sperm penetration of the corona radiata
B:Formation of a female pronucleus