Advanced Biology Reproduction Unit
What is the difference between a blastocyst and an embryo?
A blastocyst is a ball of hollow cells. An embryo is a ball of cells that has developed the ectoderm, mesoderm, and endoderm.
During prophase I _______________.
DNA coils into chromosomes and spindle fibers appear.
What are the two hormones that help to develop ova and sperm?
Estrogen helps to develop ova and testosterone helps to develop sperm.
How do gametes differ from somatic cells?
Gametes differ from somatic cells because gametes are located in the reproductive organs and are haploid. Somatic cells, on the other hand, make up the tissues and organs of the body and are diploid.
Why is it important for the mother to eat well and avoid toxic substances?
It is important for the mother to eat well and avoid toxic substances to ensure the health of her baby, as the fetus depends on the mother for all of its nourishment. This means that whatever she consumes is consumed by the baby.
How does meiosis relate to haploid cells? How does fertilization relate to diploid cells?
Meiosis relates to haploid cells because meiosis is a process that creates haploid cells. Fertilization relates to diploid cells because fertilization fuses two haploid cells to make a diploid cell.
By the time the morula has reached the uterus, the morula has become a __________.
blastocyst
While still in the fallopian tube, a zygote begins a series of mitotic divisions known as __________.
cleavage
Fertilization is to zygote as cleavage is to __________.
morula
Through crossing-over, genetic material is exchanged between maternal and paternal chromosomes, meaning _______________.
A new mixture of genetic material results in genetic recombination.
How is a zygote produced?
A zygote is produced when a sperm penetrates an egg and its nucleus fuses with the nucleus of the egg.
During which phase do sister chromatids separate?
Anaphase II
Describe the path an egg travels once it leaves the ovaries.
One it leaves the ovaries, an egg travels through the fallopian tube (also called the oviducts), to the uterus, and through the cervix.
The term synapsis comes from a Greek word meaning "point of contact." How is the term synapsis related to its Greek word of origin?
The terms synapsis is related to its Greek word of origin because it is through synapsis that chromatids on homologous chromosomes may come in contact with one another and exchange genetic material.
The fusion of sperm and egg results in a zygote, meaning _______________.
A zygote contains 46 chromosomes.
During which phase do homologous chromosomes separate?
Anaphase I
Explain what happens if the egg is not fertilized.
If the egg is not fertilized, the endometrium detaches from the uterus and the flow phase begins. This causes the egg to be expelled from the uterus.
Where are immature sperm found, and where do they mature?
Immature sperm are found in the testes. Sperm mature in the epididymis.
During synapsis, chromatids within a homologous pair may twist around one another, causing _______________.
Portions of the chromatids may break off and attach to adjacent chromatids on the homologous chromosome.
In humans, meiosis produces haploid reproductive cells called gametes, meaning _______________.
Sperm and egg cells each contain 23 chromosomes.
What structures allow the developing embryo to receive nourishment from the mother?
The chorion, placenta, and umbilical cord allow the developing embryo to receive nourishment from the mother.
What are the functions of the menstrual cycle?
The functions of the menstrual cycle are to develop and release an egg and to prepare the uterus to receive a fertilized egg.
What are the main functions of the female and male reproductive systems?
The main function of the female reproductive system is to produce ova and provide a place where the fertilized egg can mature. The main function of the male reproductive system is to produce sperm and deliver the sperm to the egg.
The prefix homo- means "the same." Explain how this meaning relates to the definition of homologous chromosomes.
This meaning relates to the definition of homologous chromosomes because homologous chromosomes look the same and carry the same genes.
Pregnancy begins at implantation, which occurs about a week after __________.
fertilization
The process in which a blastocyst burrows and embeds itself into the lining of the uterus is called __________.
implantation
Cleavage produces a ball of cells called a __________.
morula