Fertilization: The Union of Sperm and Egg

Question 1

What is the primary function of the zona pellucida during fertilization?

Accepted Answer

Preventing multiple sperm from entering the egg

Answer

Helping sperm attach to the egg

Answer

Causing the sperm to release enzymes

Answer

Providing nourishment to the embryo

Question 2

Which of the following is NOT a factor contributing to sperm capacitation?

Accepted Answer

Initiation of sperm motility

Answer

Removal of seminal plasma

Answer

Alterations in the sperm membrane composition

Answer

Exposure to the correct pH levels in the female reproductive tract

Question 3

The acrosome reaction in sperm is triggered by its binding to:

Accepted Answer

Zona pellucida

Answer

Cumulus oophorus

Answer

Cortex of the oocyte

Answer

Vitelline membrane

Question 4

Which of the following is NOT a function of the zona pellucida in fertilization?

Accepted Answer

Initiating oocyte activation

Answer

Preventing polyspermy

Answer

Triggering the acrosome reaction

Answer

Providing a pathway for sperm entry

Question 5

The process by which the plasma membranes of the sperm and oocyte merge during fertilization is termed:

Accepted Answer

Gamete fusion

Answer

Zygote formation

Answer

Cortical reaction

Answer

Amphimixis

Question 6

Which ion is responsible for the rise in intracellular calcium concentration that triggers the cortical reaction in the oocyte?

Accepted Answer

Calcium

Answer

Sodium

Answer

Potassium

Answer

Magnesium

Question 7

The cortical reaction in the oocyte prevents polyspermy by:

Accepted Answer

Hardening the zona pellucida

Answer

Depolarizing the oocyte membrane

Answer

Releasing enzymes that break down sperm

Answer

Attracting additional sperm

Question 8

Which of the following events occurs first in the fertilization process?

Accepted Answer

Sperm capacitation

Answer

Acrosome reaction

Answer

Zona pellucida penetration

Answer

Cortical reaction

Question 9

The pronuclei of the sperm and oocyte fuse to form the:

Accepted Answer

Zygote nucleus

Answer

Blastocyst

Answer

Morula

Answer

Embryo

Question 10

Assisted reproductive technologies (ARTs) can be employed to address infertility caused by:

Accepted Answer

Any of the above

Answer

Defects in sperm function

Answer

Ovulatory disorders

Answer

Damage to Fallopian tubes

Question 11

Which of the following is a key clinical implication of fertilization failure?

Accepted Answer

Infertility

Answer

Ectopic pregnancy

Answer

Multiple pregnancies

Question 12

Which layer of the egg prevents polyspermy?

Accepted Answer

Zona pellucida

Answer

Vitelline membrane

Answer

Chorion

Answer

Blastocyst

Question 13

Which hormone triggers ovulation?

Accepted Answer

Luteinizing hormone (LH)

Answer

Follicle-stimulating hormone (FSH)

Answer

Estrogen

Answer

Progesterone

Question 14

Which of the following events is NOT a step in the acrosome reaction?

Accepted Answer

Attachment to the zona pellucida

Answer

Release of hyaluronidase

Answer

Exposure of the inner acrosomal membrane

Answer

Acrosin activation

Question 15

What is the primary function of the zona pellucida in fertilization?

Accepted Answer

To facilitate sperm binding and prevent polyspermy

Answer

To provide nutrients for the developing embryo

Answer

To regulate cell division within the embryo

Answer

To fuse with the sperm plasma membrane

Question 16

Which molecule is primarily responsible for promoting sperm capacitation?

Accepted Answer

HCO3-

Answer

Progesterone

Answer

Estrogen

Answer

Albumin

Question 17

What is the term for the fusion of plasma membranes between the sperm and the oocyte?

Accepted Answer

Syngamy

Answer

Karyogamy

Answer

Cytokinesis

Answer

Cortical granule reaction

Question 18

Which of the following is NOT a factor that can influence the success of fertilization?

Accepted Answer

Financial status of the individuals

Answer

Age of the parents

Answer

Environmental conditions

Answer

Timing of ovulation

Question 19

The pronuclei in the developing zygote primarily function to:

Accepted Answer

Provide the genetic material for the embryo

Answer

Regulate gene expression

Answer

Initiate cell division

Answer

Synthesize proteins

Question 20

After fertilization, the zygote undergoes what type of cell division?

Accepted Answer

Mitosis

Answer

Meiosis

Answer

Amitosis

Answer

Binary fission

Question 21

The blastocyst's primary function is to:

Accepted Answer

Implant in the uterine lining

Answer

Differentiate into the fetal germ layers

Answer

Produce hormones

Answer

Form the placenta

Question 22

Which hormone is critical for maintaining pregnancy?

Accepted Answer

Progesterone

Answer

Estrogen

Answer

Human chorionic gonadotropin

Answer

Follicle-stimulating hormone

Question 23

Polar bodies formed during oocyte meiosis primarily serve to:

Accepted Answer

Remove excess genetic material

Answer

Ensure genetic diversity in offspring

Answer

Provide nutrients for early embryonic development

Answer

Protect the oocyte from environmental toxins

Question 24

Which of the following factors is **NOT** involved in sperm capacitation?

Accepted Answer

Induction of the acrosome reaction

Answer

Removal of seminal plasma proteins

Answer

Activation of sperm motility

Answer

Acquisition of fertilizing ability

Question 25

What is the primary function of the acrosome reaction?

Accepted Answer

Release of enzymes to penetrate the zona pellucida

Answer

Fusion of sperm with the egg plasma membrane

Answer

Prevention of polyspermy

Answer

Activation of the egg for further development

Question 26

What is the first step in the zona pellucida penetration process?

Accepted Answer

Sperm-zona binding

Answer

Acrosomal enzyme release

Answer

Zona pellucida thinning

Answer

Inner acrosomal membrane fusion

Question 27

Which hormone surge induces ovulation?

Accepted Answer

Luteinizing hormone (LH)

Answer

Estrogen

Answer

Progesterone

Answer

Follicle-stimulating hormone (FSH)

Question 28

Which layer of the egg envelope first encounters and interacts with sperm during fertilization?

Accepted Answer

Zona pellucida

Answer

Vitelline membrane

Answer

Corona radiata

Answer

Granulosa cells

Question 29

What is the primary function of the cortical reaction in the egg?

Accepted Answer

Prevents polyspermy

Answer

Activates the sperm nucleus

Answer

Forms the fertilization envelope

Answer

Stimulates cell division

Question 30

Which factor does NOT significantly affect sperm motility?

Accepted Answer

Presence of antibodies

Answer

pH

Answer

Temperature

Answer

Ion concentration

Question 31

What term describes the fusion of sperm and egg pronuclei?

Accepted Answer

Syngamy

Answer

Capacitation

Answer

Acrosome reaction

Answer

Polyspermy

Question 32

Which of the following is NOT an immediate consequence of fertilization?

Accepted Answer

Differentiation of germ layers

Answer

Stimulation of DNA synthesis

Answer

Establishment of the embryonic genome

Answer

Activation of cell division

Question 33

What is the specialized structure on the sperm that initially binds to the zona pellucida?

Accepted Answer

Acrosomal process

Answer

Equatorial segment

Answer

Post-acrosomal region

Answer

Head cap

Question 34

What is the primary function of the acrosome reaction?

Accepted Answer

To facilitate sperm penetration of the zona pellucida

Answer

To prevent the premature activation of the egg

Answer

To attract additional sperm to the egg

Answer

To provide nutrients for the developing embryo

Question 35

Which of the following structures in the egg is responsible for preventing polyspermy?

Accepted Answer

Zona pellucida

Answer

Vitelline membrane

Answer

Cortical granules

Answer

Polar bodies

Question 36

What is the significance of the cortical reaction in fertilization?

Accepted Answer

It prevents the fusion of multiple sperm with the oocyte

Answer

It releases enzymes that harden the zona pellucida

Answer

It attracts additional sperm to the egg

Answer

It initiates embryonic development

Question 37

What is the role of the pronuclei in the zygote?

Accepted Answer

To combine the genetic material of the sperm and egg

Answer

To regulate embryonic gene expression

Answer

To store nutrients for the developing embryo

Answer

To direct the first cell division

Question 38

What is the clinical significance of assisted reproductive technologies (ARTs) in treating infertility?

Accepted Answer

They enable fertilization to occur outside the body

Answer

They guarantee a successful pregnancy

Answer

They eliminate the need for invasive medical procedures

Answer

They prevent genetic disorders in offspring

Question 39

What is the primary goal of preimplantation genetic testing (PGT)?

Accepted Answer

To identify genetic abnormalities in embryos before implantation

Answer

To select embryos with specific desired traits

Answer

To increase the chances of a multiple pregnancy

Answer

To prevent miscarriage in high-risk pregnancies

Question 40

Which of the following is associated with the zona reaction?

Accepted Answer

Release of cortical granules

Answer

Embryo cleavage

Answer

Sperm-oocyte fusion

Answer

Acrosome reaction

Question 41

What is the primary mechanism by which sperm capacitation occurs in the female reproductive tract?

Accepted Answer

Removal of seminal plasma proteins

Answer

Induction of the acrosome reaction

Answer

Binding to the zona pellucida

Answer

Acquisition of motility

Question 42

Which of the following enzymes is responsible for the breakdown of the zona pellucida during sperm penetration?

Accepted Answer

Acrosin

Answer

Neuraminidase

Answer

Trypsin

Answer

Lipase

Question 43

Which of the following factors does NOT contribute to the species specificity of fertilization?

Accepted Answer

Sperm motility

Answer

Zona pellucida glycoproteins

Answer

Acrosomal enzymes

Question 44

What is the primary advantage of using animal models to study human fertilization?

Accepted Answer

Allows for controlled experimentation and observation

Answer

Provides data directly applicable to human reproduction

Answer

Eliminates ethical concerns associated with human research

Question 45

Which of the following enzymes is responsible for the breakdown of the zona pellucida, allowing sperm penetration?

Accepted Answer

Acrosin

Answer

Chymotrypsin

Answer

Trypsin

Answer

Hyaluronidase

Question 46

Sperm capacitation, a process essential for fertilization, involves which of the following changes?

Accepted Answer

Increased membrane fluidity and hyperactivation

Answer

Decreased membrane fluidity and hyperpolarization

Answer

Increased membrane fluidity and depolarization

Answer

Decreased membrane fluidity and hyperactivation

Question 47

The fusion of the sperm and egg plasma membranes triggers which of the following events?

Accepted Answer

Cortical reaction

Answer

Capacitation

Answer

Oocyte maturation

Answer

Acrosome reaction

Question 48

Which of the following statements accurately describes the role of the zona pellucida in fertilization?

Accepted Answer

It acts as a barrier that prevents polyspermy and facilitates sperm binding.

Answer

It is a layer of cells that surrounds the oocyte and provides structural support.

Answer

It is the site of the acrosome reaction.

Question 49

A patient presents with infertility due to a genetic defect affecting the formation of the acrosome. Which of the following processes is likely to be impaired?

Accepted Answer

Sperm penetration of the zona pellucida

Answer

Oocyte maturation

Answer

Sperm capacitation

Answer

Cortical reaction

Question 50

The cortical reaction, triggered by sperm-egg fusion, plays a crucial role in preventing which of the following?

Accepted Answer

Polyspermy

Answer

Oocyte maturation

Answer

Sperm capacitation

Answer

Acrosome reaction

Question 51

Which of the following molecules is responsible for mediating the binding of sperm to the zona pellucida?

Accepted Answer

ZP3

Answer

ZP2

Answer

ZP4

Answer

ZP1

Question 52

A patient presents with a history of repeated miscarriages. Which of the following factors related to fertilization could contribute to this condition?

Accepted Answer

Defective sperm-egg fusion

Answer

Normal oocyte maturation

Answer

Successful sperm capacitation

Answer

Effective cortical reaction

Question 53

The completion of meiosis II in the oocyte occurs at which stage of fertilization?

Accepted Answer

After sperm penetration

Answer

During the acrosome reaction

Answer

Before sperm capacitation

Answer

During sperm-egg binding

Question 54

Which of the following best describes the genetic contribution of the sperm to the zygote?

Accepted Answer

Haploid set of chromosomes

Answer

Mitochondrial DNA

Answer

Diploid set of chromosomes

Answer

Centrioles only