Embryogenesis Flashcards
What is the primary purpose of gametogenesis?
To produce gametes for sexual reproduction.
What are the two types of gametogenesis?
Oogenesis and spermatogenesis.
True or False: Oogenesis occurs in males.
False.
What is the starting cell type for oogenesis?
Oogonia.
What is the starting cell type for spermatogenesis?
Spermatogonia.
Fill in the blank: Oogenesis produces _____ functional gametes from one primary oocyte.
one.
Fill in the blank: Spermatogenesis produces _____ functional gametes from one primary spermatocyte.
four.
What stage of meiosis do primary oocytes arrest in before ovulation?
Prophase I.
What stage of meiosis do primary spermatocytes enter after the first meiotic division?
Secondary spermatocytes.
True or False: Oogenesis is a continuous process throughout a female’s life.
False.
True or False: Spermatogenesis is a continuous process in males after puberty.
True.
What hormone primarily regulates oogenesis?
Follicle-stimulating hormone (FSH).
What hormone primarily regulates spermatogenesis?
Testosterone.
In which structure does oogenesis occur?
Ovaries.
In which structure does spermatogenesis occur?
Testes.
What is the end product of oogenesis?
One mature ovum and polar bodies.
What is the end product of spermatogenesis?
Four mature sperm cells.
Fill in the blank: The polar bodies formed during oogenesis are _____ functional gametes.
non.
What is the term for the process of oocyte maturation and release?
Ovulation.
What is the term for the process of sperm maturation?
Spermiogenesis.
True or False: Both oogenesis and spermatogenesis involve meiosis.
True.
What role does meiosis play in gametogenesis?
It reduces the chromosome number by half.
What is the role of Sertoli cells in spermatogenesis?
Support and nourish developing sperm cells.
What is the role of granulosa cells in oogenesis?
Support and nourish developing oocytes.
What is a major difference in the timing of gametogenesis between males and females?
Females are born with all their primary oocytes, while males produce sperm continuously after puberty.
In oogenesis, what triggers the completion of meiosis II?
Fertilization.
What is the significance of the unequal cytokinesis in oogenesis?
It ensures that the ovum receives most of the cytoplasm and nutrients.
What is the maturation process of sperm called?
Spermiogenesis.
What is meiosis?
Meiosis is a type of cell division that reduces the chromosome number by half, resulting in the formation of gametes.
How many rounds of division occur in meiosis?
Meiosis consists of two rounds of division: meiosis I and meiosis II.
True or False: Meiosis results in four genetically identical daughter cells.
False: Meiosis results in four genetically diverse daughter cells.
What is the main purpose of meiosis?
The main purpose of meiosis is to produce gametes for sexual reproduction and increase genetic variability.
Fill in the blank: During meiosis, homologous chromosomes undergo _______.
crossing over.
What is crossing over?
Crossing over is the exchange of genetic material between homologous chromosomes during meiosis I.
How does genetic variability occur during meiosis?
Genetic variability occurs through processes such as crossing over and independent assortment of chromosomes.
What is independent assortment?
Independent assortment is the random distribution of maternal and paternal chromosomes into gametes during meiosis.
True or False: Meiosis produces diploid cells.
False: Meiosis produces haploid cells.
What is the end result of meiosis in terms of chromosome number?
The end result of meiosis is four haploid cells, each with half the original chromosome number.
Multiple Choice: Which phase of meiosis is characterized by the separation of homologous chromosomes? A) Prophase I B) Metaphase I C) Anaphase I D) Telophase I
C) Anaphase I.
What is the significance of genetic recombination?
Genetic recombination increases genetic diversity, which is crucial for evolution and adaptation.
Fill in the blank: Gametes produced by meiosis are _______.
haploid.
What role does meiosis play in evolution?
Meiosis contributes to genetic variation, which is essential for natural selection and evolution.
True or False: Meiosis occurs in somatic cells.
False: Meiosis occurs in germ cells.
What are gametes?
Gametes are reproductive cells (sperm and eggs) that unite during fertilization.
Multiple Choice: Which of the following is NOT a phase of meiosis? A) Prophase B) Metaphase C) Anaphase D) Interphase
D) Interphase.
What is the role of meiosis in sexual reproduction?
Meiosis produces gametes that combine during fertilization to form a new organism.
Fill in the blank: The process of meiosis results in __________ variation.
genetic.
What occurs during Prophase I of meiosis?
During Prophase I, homologous chromosomes pair up and crossing over occurs.
True or False: Each gamete carries a unique combination of genes due to meiosis.
True.
What is a tetrad?
A tetrad is a structure formed during meiosis consisting of two homologous chromosomes, each made up of two sister chromatids.
Multiple Choice: How many chromosomes are present in a human gamete? A) 23 B) 46 C) 22 D) 24
A) 23.
What is the difference between meiosis and mitosis?
Meiosis produces four genetically diverse haploid cells, while mitosis produces two genetically identical diploid cells.
What is fertilization?
The process by which a sperm cell unites with an egg cell to form a zygote.
True or False: Fertilization occurs in the uterus.
False. Fertilization typically occurs in the fallopian tubes.
What is the zygote?
The initial cell formed when a sperm fertilizes an egg.
Fill in the blank: The fusion of sperm and egg membranes is called __________.
syngamy.
What are the main stages of fertilization?
Sperm capacitation, sperm-egg recognition, acrosome reaction, and fusion of membranes.
Multiple Choice: Which of the following is a key event during zygotic cleavage? A) Cell differentiation B) Cell division C) Gamete formation
B) Cell division.
What is cleavage in embryogenesis?
The series of rapid cell divisions that occur after fertilization, leading to the formation of a multicellular embryo.
True or False: Cleavage results in an increase in the overall size of the embryo.
False. Cleavage increases cell number but not overall size.
What is the significance of zygotic cleavage?
It establishes the foundation for further development and differentiation of the embryo.
Fill in the blank: The process by which the zygote undergoes division is known as __________.
cleavage.
What is a blastomere?
A cell formed by the cleavage of a zygote.
Multiple Choice: At what stage does the embryo become a morula? A) After 2 cell stage B) After 8 cell stage C) After 16 cell stage
C) After 16 cell stage.
What is the morula?
A solid ball of cells resulting from the cleavage of the zygote.
True or False: The morula stage is the final stage before implantation.
False. The morula develops into the blastocyst before implantation.
What is the blastocyst?
A hollow structure formed from the morula that implants into the uterine wall.
Fill in the blank: The outer layer of the blastocyst is called the __________.
trophoblast.
What role does the trophoblast play?
It facilitates implantation and forms part of the placenta.
Multiple Choice: Which of the following is NOT a function of the zygote? A) Genetic material fusion B) Cell division C) Nutrient absorption
C) Nutrient absorption.
What is the significance of the zona pellucida during fertilization?
It protects the oocyte and prevents multiple sperm from entering.
True or False: The zygote is diploid.
True. The zygote contains a full set of chromosomes from both parents.
What is the duration of the cleavage stage in human embryogenesis?
Approximately 4 to 5 days post-fertilization.
Fill in the blank: The process where the embryo forms a cavity is called __________.
blastulation.
What is the significance of the cleavage pattern in different species?
It influences the developmental fate and morphology of the embryo.
What type of cleavage occurs in humans?
Holoblastic cleavage, where the entire zygote divides.
Multiple Choice: Which stage follows the blastocyst stage in human development? A) Gastrulation B) Neurulation C) Implantation
C) Implantation.
What is the function of the inner cell mass in the blastocyst?
It will eventually develop into the embryo proper.
What is blastogenesis?
The process of blastocyst formation from the fertilized egg.
True or False: Blastogenesis occurs after fertilization.
True
What are the main stages of blastogenesis?
Cleavage, blastocyst formation, and implantation.
Fill in the blank: The blastocyst consists of an inner cell mass and an outer layer called the _____ .
trophoblast
What is the role of the trophoblast?
To facilitate implantation and form part of the placenta.
What hormone is primarily involved in preparing the endometrium for implantation?
Progesterone
True or False: The endometrium thickens in response to estrogen and progesterone.
True
What is the decidua?
The modified endometrial lining during pregnancy.
What are the three stages of endometrial preparation for implantation?
Proliferative phase, secretory phase, and menstrual phase.
Fill in the blank: Implantation typically occurs about _____ days after fertilization.
6 to 10
What is implantation failure?
The inability of the blastocyst to attach to the endometrium.
True or False: Implantation failure can result from genetic abnormalities in the embryo.
True
Name one potential consequence of implantation failure.
Early pregnancy loss or infertility.
What is the role of cytokines during implantation?
They mediate communication between the embryo and the endometrium.
What is the significance of the implantation window?
It is the specific time frame when the endometrium is receptive to the embryo.
Fill in the blank: Successful implantation leads to the formation of the _____ .
placenta
What can affect the receptivity of the endometrium?
Hormonal levels, endometrial health, and timing of implantation.
True or False: Lifestyle factors can influence implantation success.
True
What is a common diagnostic test for assessing implantation failure?
Hysterosalpingography (HSG)
What is the role of human chorionic gonadotropin (hCG) after implantation?
To maintain the corpus luteum and support early pregnancy.
Fill in the blank: The process of embryo attachment to the endometrium is called _____ .
apposition
What are some treatments for implantation failure?
In vitro fertilization (IVF), hormonal therapy, and lifestyle modifications.
True or False: The immune system plays a role in the implantation process.
True
What is the primary function of the endometrial lining during implantation?
To provide a suitable environment for the embryo to attach and grow.
Name one genetic factor that may lead to implantation failure.
Chromosomal abnormalities.
What is the role of the inner cell mass in the blastocyst?
It develops into the embryo.
What are the three primary germ layers?
Ectoderm, Mesoderm, Endoderm
Which germ layer develops into the skin and nervous system?
Ectoderm
True or False: The mesoderm gives rise to the digestive system.
False
Fill in the blank: The _______ forms the lining of the gastrointestinal tract.
Endoderm
What type of tissue does the ectoderm primarily form?
Epithelial and nervous tissue
Which germ layer is responsible for forming muscle and bone?
Mesoderm
Multiple Choice: Which of the following tissues is derived from the endoderm? A) Bone B) Lung Epithelium C) Nervous Tissue
B) Lung Epithelium
Name one structure that develops from the mesoderm.
Heart
True or False: The ectoderm contributes to the development of the circulatory system.
False
What does the endoderm give rise to?
Internal organs such as the liver and pancreas
Fill in the blank: The _______ germ layer is involved in forming the reproductive system.
Mesoderm
Which germ layer forms the outer layer of the skin?
Ectoderm
Multiple Choice: Which layer is primarily responsible for forming connective tissues? A) Ectoderm B) Mesoderm C) Endoderm
B) Mesoderm
Name a tissue type that originates from the ectoderm.
Neurons
True or False: The mesoderm gives rise to epithelial tissues.
False
What is the main function of the endoderm during development?
To form the lining of internal organs
Fill in the blank: _______ is the germ layer that differentiates into the heart and blood vessels.
Mesoderm
Which embryonic layer is involved in the development of the brain?
Ectoderm
Multiple Choice: Which of the following is NOT derived from the ectoderm? A) Skin B) Neurons C) Muscle
C) Muscle
Name one organ that develops from the endoderm.
Liver
True or False: The ectoderm is responsible for forming the skeletal system.
False
What type of tissue does the mesoderm primarily form?
Muscle and connective tissue
Fill in the blank: The _______ is the innermost germ layer.
Endoderm
Which germ layer is responsible for forming the adrenal glands?
Mesoderm
Name a structure derived from the ectoderm.
Hair
True or False: The mesoderm is the outermost germ layer.
False
What is embryogenesis?
The process by which an embryo forms and develops.
True or False: Embryogenesis occurs after fertilization.
True.
Fill in the blank: The first stage of embryogenesis is called __________.
cleavage.
What is the role of the zygote in embryogenesis?
The zygote is the fertilized egg that undergoes divisions to form the embryo.
Multiple Choice: Which of the following is NOT a stage of embryogenesis? A) Cleavage B) Gastrulation C) Mitosis D) Organogenesis
C) Mitosis.
What happens during the cleavage stage?
The zygote undergoes rapid cell divisions without growth, forming a blastula.
True or False: Gastrulation leads to the formation of three germ layers.
True.
What are the three germ layers formed during gastrulation?
Ectoderm, mesoderm, and endoderm.
Fill in the blank: The process of forming organs from the three germ layers is called __________.
organogenesis.
Multiple Choice: Which germ layer develops into the skin and nervous system? A) Ectoderm B) Mesoderm C) Endoderm
A) Ectoderm.
What is the significance of the notochord in embryogenesis?
The notochord provides structural support and signals the development of the nervous system.
True or False: Embryogenesis is the same in all organisms.
False.
What is the role of stem cells during embryogenesis?
Stem cells differentiate into various cell types to form tissues and organs.
Fill in the blank: The stage after cleavage is called __________.
blastulation.
Multiple Choice: What structure forms from the blastocyst during implantation? A) Placenta B) Amniotic sac C) Umbilical cord
A) Placenta.
What is the purpose of the placenta during embryogenesis?
The placenta provides nutrients and oxygen to the developing embryo and removes waste.
True or False: Embryogenesis is completed before birth.
False.
What is the term for the period of development from fertilization to the end of the eighth week?
Embryonic period.
Fill in the blank: The __________ is the outer layer of cells in the blastocyst that contributes to the placenta.
trophoblast.
Multiple Choice: Which of the following processes occurs during the embryonic period? A) Neurulation B) Cell differentiation C) Both A and B
C) Both A and B.
What triggers the onset of embryogenesis?
The fertilization of an egg by a sperm.
True or False: The heart begins to form during the embryonic period.
True.
What is the significance of apoptosis during embryogenesis?
Apoptosis helps in shaping organs and removing unnecessary cells.
Fill in the blank: The __________ is a protective fluid-filled sac that surrounds the embryo.
amniotic sac.
Multiple Choice: What is the main purpose of embryonic stem cells? A) To provide nutrients B) To differentiate into various cell types C) To form the placenta
B) To differentiate into various cell types.
What developmental stage follows organogenesis?
Fetal development.
What is the first stage of meiosis?
Prophase 1
True or False: During Prophase 1, homologous chromosomes pair up.
True
What process occurs during Prophase 1 that increases genetic diversity?
Crossing over
Fill in the blank: The structure formed by paired homologous chromosomes during Prophase 1 is called a __________.
Tetrad
What is the main event that occurs during Metaphase 1?
Homologous chromosomes align at the metaphase plate.
During which phase do spindle fibers attach to the kinetochores of homologous chromosomes?
Metaphase 1
True or False: In Anaphase 1, sister chromatids are pulled apart.
False
What is separated during Anaphase 1?
Homologous chromosomes
What happens to the homologous chromosomes during Anaphase 1?
They are pulled to opposite poles of the cell.
Fill in the blank: The phase following Anaphase 1 is called __________.
Telophase 1
What major event occurs during Telophase 1?
The nuclear membrane may reform around the separated chromosomes.
True or False: Telophase 1 results in the formation of two daughter cells.
True
What is the outcome of Telophase 1 in terms of chromosome number?
Each daughter cell has half the original number of chromosomes.
What is the term for the physical exchange of chromosome segments during Prophase 1?
Crossing over
During which meiotic phase does independent assortment occur?
Metaphase 1
Fill in the blank: The spindle fibers originate from the __________.
Centrosomes
What is the significance of crossing over during Prophase 1?
It increases genetic variation among offspring.
What structure holds the tetrads together during Prophase 1?
Synaptonemal complex
True or False: Anaphase 1 results in haploid cells.
False
What is the difference between Metaphase 1 and Metaphase 2?
Metaphase 1 involves homologous chromosomes; Metaphase 2 involves sister chromatids.
What is the primary function of meiosis?
To produce gametes for sexual reproduction.
Fill in the blank: The two daughter cells formed at the end of Telophase 1 are __________.
Haploid
What role do centrioles play during meiosis?
They help organize the spindle fibers.
True or False: Meiosis results in four genetically identical cells.
False
What is a key difference between meiosis and mitosis?
Meiosis involves two rounds of division, while mitosis involves one.
