Human Anatomy and Reproduction Quiz

Cells that produce gametes (sperm or egg cells) through meiosis.

A cell containing two sets of chromosomes (2n).

A cell containing one set of chromosomes (1n).

Cell division process that produces gametes with half the number of chromosomes.

Reproductive cells (sperm and egg) that have a haploid number of chromosomes.

Homologous pairs separate into two daughter cells, reducing the chromosome number.

The chromosome number goes from double to single.

Matching chromosome pairs.

The two new cells produced from cell division.

The number of chromosomes is cut in half from diploid to haploid.

A single set of chromosomes, found in gametes (sex cells).

Two sets of chromosomes, found in somatic cells (body cells).

Union of gametes (sperm and egg).

Region where sister chromatids are joined after chromosome replication.

Special cells in the developing embryo that are destined to become either sperm or eggs.

Early female germ cells that are diploid, containing two sets of chromosomes.

Oogonia divide by mitosis, a process that creates genetically identical copies of the cell. This produces a large pool of germ cells.

The process where most oogonia degenerate before birth, leading to a significant decrease in the number of germ cells.

Oogonia contain two complete sets of chromosomes, making them diploid (2n).

A cap-like structure on the head of a sperm cell containing enzymes that help the sperm penetrate the egg's outer layer.

An enzyme found in the acrosome of sperm that breaks down hyaluronic acid, a component of the egg's outer layer.

The thick, glycoprotein layer surrounding the egg cell.

Enzymes released from the acrosome, like acrosin, esterases, and neuraminidase, that dissolve the zona pellucida, allowing the sperm to reach the egg.

The merging of the sperm's outer membrane with the egg's outer membrane.

Changes in the zona pellucida (ZP) that make it impermeable to other sperm. This prevents multiple sperm from fertilizing a single egg.

The second division in meiosis that occurs in the oocyte after fertilization. It produces a haploid egg cell with one set of chromosomes.

The zona pellucida (ZP), a protective coating surrounding the egg, undergoes changes after fertilization (zona reaction) to prevent additional sperm from entering.

The mature egg cell produced after the second meiotic division, containing only one set of chromosomes.

Fertilization involves the union of a sperm and an egg. It triggers the zona reaction, preventing further sperm entry. It also initiates the second meiotic division of the oocyte, culminating in the production of a haploid egg cell.

A hollow ball of cells formed from the morula, consisting of an inner cell mass and an outer layer called the trophoblast.

The cluster of cells inside the blastocyst that will eventually develop into the embryo.

The outer layer of cells surrounding the blastocyst that will form the placenta.

The process by which fluid enters the morula through the zona pellucida, creating the blastocyst.

Before meiosis I begins, the cell replicates its DNA, creating sister chromatids for each chromosome.

Fertilization that occurs outside of the body, allowing the union of sperm and egg in a controlled laboratory setting.

The single-celled stage of a new organism formed by the fusion of a sperm and an egg.

The process of preserving sperm or eggs at very low temperatures for later use.

The fusion of sperm and egg initiates a series of events in the egg, including changes to the zona pellucida.

A protein complex on the chromosome where spindle fibers attach during cell division, allowing chromosomes to be pulled apart.

Microtubules that extend from the poles of the cell during cell division and attach to kinetochores on chromosomes, pulling them apart.

The region where sister chromatids (copied chromosomes) are joined together. This is the central point of attachment for the kinetochore.

Two identical copies of a chromosome created during DNA replication, connected at the centromere.

The kinetochore ensures that chromosomes are correctly attached to spindle fibers and pulled apart during cell division, ensuring that each new cell gets a full set of chromosomes.

The first stage of mitosis, where chromosomes condense and become visible, the nuclear envelope breaks down, and the mitotic spindle begins to form.

The stage of mitosis where chromosomes line up along the center of the cell, attached to the mitotic spindle fibers.

The stage of mitosis where sister chromatids (identical copies of chromosomes) are pulled apart by the spindle fibers to opposite poles of the cell.

The final stage of mitosis where two daughter nuclei form, the chromosomes uncoil, and the cytoplasm divides to form two new cells.

During synapsis, homologous chromosomes align themselves in pairs. This pairing is exact, matching point for point, except for the XY combination.

The process where homologous chromosomes pair up during meiosis I, forming tetrads (groups of four chromatids).

The sex chromosomes, X and Y, are not completely homologous. This means they don't pair up perfectly like other chromosome pairs.

Groups of four chromatids formed during synapsis, where homologous chromosomes pair up.

Sperm travel from the vagina, through the cervix and uterus, and finally into the fallopian tubes where fertilization might happen.

Muscle contractions in the fallopian tubes, like waves, propel the sperm towards the egg.

The average number of sperm in a healthy male ejaculate is 200-600 million.

Sperm are very active and can move independently.

Fertilization usually occurs in the fallopian tubes, where sperm meet the egg.

A hollow ball of cells (blastocyst) forms as intercellular spaces merge during early embryonic development.

A hollow ball of cells, formed from the morula, consisting of an inner cell mass (embryo) and a trophoblast (placenta).

The process where a blastocyst burrows into the endometrium of the uterus, establishing pregnancy.

The inner lining of the uterus, which thickens during the menstrual cycle to prepare for implantation.

Implantation typically begins around the 6th-8th day after fertilization and is complete by the 12th day.

Cells derived from the inner cell mass of a blastocyst, capable of differentiating into any cell type in the body.

Describing a cell that can develop into many different cell types in the body.

The front or ventral surface of the body.

The back or dorsal surface of the body.

Any cell in the body except germ cells (sperm and egg cells).

A protein complex that attaches to the centromere of a chromosome during cell division, serving as the point of attachment for spindle fibers.

The kinetochore is essential for the correct attachment of chromosomes to spindle fibers, ensuring they are pulled apart to opposite poles of the cell during cell division. This ensures each daughter cell receives a full set of chromosomes.

The process of creating different combinations of genes in offspring through meiosis.

The exchange of genetic material between homologous chromosomes during meiosis I.

Crossover shuffles genes between homologous chromosomes, creating unique combinations in daughter cells.

Genetic variability increases the chances of survival in a changing environment by creating diverse offspring.

Crossover leads to unique combinations of genes in the gametes (sperm and egg) produced during meiosis, increasing genetic diversity in offspring.

Except for the XY combination, homologous chromosomes align perfectly point-for-point.

Matching chromosome pairs, one from each parent.

The process by which sperm cells are produced in the testes, starting at puberty.

The process by which egg cells are produced in the ovaries, starting during fetal development and resuming at puberty.

The complete process of spermatogenesis takes approximately 2 months (64 days).

Spermatogenesis begins at puberty and produces millions of sperm cells continuously, while oogenesis starts before birth, stops during meiosis I, and resumes at puberty, producing only a limited number of eggs.

Spermatogenesis begins at puberty, typically between the ages of 13 and 16 years old.

A solid ball of cells formed after several cell divisions of the fertilized egg.

A fertilized egg that is mature enough to survive outside the uterus.

Fertilization is when a sperm cell and an egg cell fuse. It triggers the zona reaction, preventing other sperm from entering. The egg then begins the process of cell division.

Meiosis is a cellular division process that creates gametes (sperm and eggs) with half the number of chromosomes compared to somatic cells. This ensures that when a sperm and egg fuse during fertilization, the offspring receives the correct number of chromosomes.

Genetic variability in offspring is achieved through meiosis, particularly through crossover. Crossover is the exchange of genetic material between homologous chromosomes, leading to unique gene combinations in the gametes.

The process where primitive sperm cells (spermatogonia) divide and grow into spermatocytes. It's the first stage of spermatogenesis.

The division of spermatocytes (2n) into haploid cells (spermatids, 1n). This happens in two phases: Meiosis I and Meiosis II.

Haploid cells produced after meiosis. They are the precursors to mature sperm cells.

The acrosome is a cap-like structure on the head of a sperm cell, containing enzymes that help the sperm penetrate the egg's outer layer (zona pellucida) during fertilization.

Sperm must fertilize an egg within 12 hours of ovulation. After 24 hours, the egg will degenerate and become unable to be fertilized.

Fertilization typically occurs in the fallopian tubes, where sperm meet the egg cell.

If an egg is not fertilized within 24 hours, it will degenerate and break down in the body.

Fertilization is the essential step for creating a new individual. It marks the beginning of pregnancy and triggers the developmental journey of a fertilized egg.

The outer layer of cells surrounding the egg, composed of cumulus cells that provide nutrients and support.

The fusion of the sperm's plasma membrane with the egg's plasma membrane triggers the zona reaction.

The process where the blastocyst embeds itself into the endometrium of the uterus, marking the start of pregnancy.

A multinucleated layer of cells that forms from the trophoblast, playing a crucial role in implantation and nutrient exchange.

A blood clot that forms at the site of implantation, sealing the opening and preventing further bleeding.

The outer layer of cells covering the endometrium, which heals over the original defect caused by blastocyst implantation.

The ability of certain cells, like the syncytiotrophoblast, to engulf and digest foreign particles or cellular debris.

The process of sperm cell production in males begins at puberty, usually between 13 and 16 years old.

Egg cell production in females starts during fetal development but pauses during meiosis I and resumes at puberty.

Haploid cells produced after meiosis in spermatogenesis. They are the precursors to mature sperm cells.

The acrosome, a cap on the sperm head, contains enzymes that help sperm penetrate the egg's outer layer during fertilization.

A large cell produced during oogenesis, visible to the naked eye. It stops at metaphase II of meiosis until fertilization occurs.

The secondary oocyte will degenerate (break down) and be reabsorbed by the body.

A newborn female ovary contains around 1 million primary oocytes.

Only around 400 mature secondary oocytes are ovulated during a woman's lifetime.

A follicle that has developed a cavity (antrum) filled with fluid, secreted by cells surrounding the oocyte.

The fluid-filled cavity within a secondary follicle, which develops as cells around the oocyte secrete a fluid.

In the secondary follicle, cells surrounding the oocyte secrete a fluid, creating a cavity called the antrum. This is a crucial step in follicle development, preparing the oocyte for ovulation.

The antrum serves as a space for fluid accumulation within the secondary follicle. This fluid provides nourishment for the oocyte and plays a role in the development and eventual release of the mature egg cell.

The secretion of fluid by cells around the oocyte creates the antrum, a critical step in the transformation of a primary follicle into a secondary follicle.

A small, non-functional cell produced along with the secondary oocyte during meiosis I in a secondary follicle.

After puberty, meiosis I resumes in several secondary follicles. This process leads to the formation of a secondary oocyte and the first polar body.

Although several secondary follicles begin meiosis I, only one will mature fully into an egg cell.

The secondary oocyte and the first polar body are both haploid cells, containing half the usual number of chromosomes.

Meiosis is a cell division process that reduces the number of chromosomes in a cell by half. This is crucial for creating haploid gametes from diploid germ cells.

Gametes are the reproductive cells, sperm and egg, that have a haploid number of chromosomes (1n). They are produced from germ cells through meiosis.

Fertilization is the union of a sperm and an egg. It combines the haploid chromosomes from each gamete, creating a diploid zygote with the full number of chromosomes.

The zygote is the single-celled stage of a new organism. It is formed by the fusion of a sperm and egg during fertilization, combining the genetic material from both parents.

A blastocyst that has shed its zona pellucida, allowing it to implant in the uterine wall.

The process by which the blastocyst's cells specialize into two distinct layers: the trophoblast and the inner cell mass.

A thick, glycoprotein layer surrounding the egg cell that protects it and helps guide sperm to fertilize it.