AP Biology : Understanding Other Reproductive Physiology

Study concepts, example questions & explanations for AP Biology

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Example Questions

Example Question #31 : Understanding Other Reproductive Physiology

Which of the following processes allows for the fusion of the genetic material of the sperm and egg?

Possible Answers:

Meiosis I

Meiosis II

All of meiosis

Mitosis

Correct answer:

Mitosis

Explanation:

After sperm cell and oocyte plasma membrane fusion, the sperm pronucleus moves into the oocyte cytoplasm. The sperm and egg pronuclei migrate towards the center of the cell while performing DNA replication, where both nuclear membranes dissolve. The chromosomes are prevented from dispersing by a mitotic spindle that tethers the maternal and paternal genetic material together. The cell then begins mitosis, which fuses the genetic material into a single diploid genome.

Example Question #32 : Understanding Other Reproductive Physiology

Which of the following features of egg activation releases the egg from the metaphase II meiotic arrest?

Possible Answers:

Hyaline layer formation

Fusion of sperm and oocyte plasma membrane 

Cortical granule exocytosis

Intracellular calcium release 

Correct answer:

Intracellular calcium release 

Explanation:

During oogenesis, specifically ootidogenesis, the secondary oocyte halts development and arrests its growth at metaphase II of meiosis. This arrest is maintained through ovulation until fertilization in the fallopian tube. During fertilization, the cortical reaction in the oocyte acts as the slow block to polyspermy and starts with the release of intracellular calcium. This release of calcium ions allows the egg to resume meiosis and ends the metaphase II arrest. 

Example Question #33 : Understanding Other Reproductive Physiology

Which of the following characteristics is not true regarding the fast block to polyspermy?

Possible Answers:

It is an electrical block

It is a faster block for the many sperm surrounding the egg

There is an influx of calcium ions

The egg develops a positive charge

Correct answer:

There is an influx of calcium ions

Explanation:

The fast block to polyspermy is the initial method that prevents polyspermy by the large number of sperm cells surrounding the egg. The fast block is triggered by sperm binding, which initiates a change in membrane potential. There is a large influx of sodium ions into the egg, creating a depolarization event that prevents further sperm penetration.

Example Question #31 : Understanding Other Reproductive Physiology

Which of the following best represents a difference between the fast and slow blocks to polyspermy?

Possible Answers:

Fast block involves sodium ion transport and the slow block involves calcium ion transport

The fast block involves an increase in intracellular ion concentration and the slow block does not

None of these

Sperm cells can overcome the fast block to polyspermy but not the slow block

Correct answer:

Fast block involves sodium ion transport and the slow block involves calcium ion transport

Explanation:

Both the fast and slow blocks to polyspermy prevent the penetration of a second sperm cell into the oocyte. The fast block to polyspermy is the initial and immediate block upon sperm binding. The fast block is an electrical block caused when oocyte membrane depolarization is started by an influx of calcium ions. The slow block is characterized by a change in zona pellucida makeup through the cortical reaction, which prevents sperm cell binding. The cortical reaction is triggered by the release of intracellular calcium.

Example Question #31 : Understanding Other Reproductive Physiology

Which of the following best describes how dizygotic twins are produced?

Possible Answers:

Fertilization of one egg by two sperm 

Nondisjunction

One zygote splits into two embryos during development 

Two eggs are released and fertilized 

Correct answer:

Two eggs are released and fertilized 

Explanation:

Dizygotic twins are produced by the release and fertilization of two separate egg cells. Both zygotes implant in the uterus and develop. The resulting twins will not be genetically identical because they arise from different gametes.

Example Question #34 : Understanding Other Reproductive Physiology

Which of the following best describes how monozygotic twins are produced?

Possible Answers:

One zygote splits into two embryos during development 

Nondisjunction

Two eggs are released and fertilized 

Fertilization of one egg by two sperm 

Correct answer:

One zygote splits into two embryos during development 

Explanation:

Monozygotic twins are produced when a zygote divides into two embryos. This process is spontaneous and may result from blastocyst collapse. The resulting twins are genetically identical because they are produced from the same gametes.

Example Question #341 : Systems Physiology

If polyspermy does occur, which of the following symptoms will the resulting organism exhibit?

Possible Answers:

The offspring will develop learning disabilities

The offspring will possess developmental delays

The zygote is inviable

The offspring will experience stunted physical growth 

Correct answer:

The zygote is inviable

Explanation:

Polyspermy, or the fertilization of an egg by more than one sperm cell, creates an inviable zygote that will not develop.

Example Question #341 : Systems Physiology

Which of the following choices does not cause infertility?

Possible Answers:

Ovulation problems 

Alcohol use

Low semen quality 

Sexually transmitted diseases

Correct answer:

Alcohol use

Explanation:

Infertility is the inability to reproduce. There are many causes for infertility and many unexplained cases. The causes include sexually transmitted diseases, ovulation problems, and low semen quality.

Example Question #35 : Understanding Other Reproductive Physiology

During the process of fertilization, what does the term "syngamy" refer to?

Possible Answers:

The fusion of two genomes

Fast block to polyspermy

Cortical granule formation 

Pronuclei membrane degradation

Correct answer:

The fusion of two genomes

Explanation:

"Syngamy" is a term that refers to the joining of two genomes during fertilization. This occurs through the first mitotic division of the zygote, after the membranes of the pronuclei dissolve.

Example Question #1622 : Ap Biology

Which of the following definitions does the term “menarche” refer to?

Possible Answers:

When menstrual periods begin in human females

Implantation of the embryo in human females

Contractions preceding vaginal delivery 

When menstrual periods stop in human females

Correct answer:

When menstrual periods begin in human females

Explanation:

“Menarche” is the term that refers to the onset of menstrual bleeding in female humans. The timing of menarche is influenced by variety of factors including genetics and environmental factors. Age of menarche is typically between 12 to 15 years old.

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