A karyotype is a complete:

diploid complement display of homologous chromosome pairs.

The most common form of fetal testing is:

amniocentesis.

Muscle tissue is formed by the ________.

mesoderm

Humans have ____ pairs of chromosomes

23

The process by which the three primary germ layers form is known as _______.

gastrulation

Estrogen and progesterone maintain the integrity of the uterine lining and prepare the mammary glands to secrete milk. Which of the following structures makes this possible during the first three months of pregnancy?

corpus luteum

Which sequence shows the correct order of the stages of labor?

Dilation, expulsion, placental

Ovulation in a typical, or "average," cycle usually occurs on day:

14

The organ that makes estrogen and progesterone is the:

Ovary

Which factor below is NOT considered to be a teratogen?

Oxygen

Which male structure is homologous to the female's clitoris?

Penis

At which stage of labor is the "afterbirth" expelled?

placental

Which of the following disorders is NOT inherited as simple recessive traits?

Down syndrome

Which process listed below separates linked genes during meiosis?

Chiasma, or crossing over

An implantation that takes place in a site other than the uterus is called:

ectopic.

The usual site of fertilization is the:

uterine tube.

The uterine layer shed with each monthly cycle is the:

functional layer of endometrium.

What is the probability of having a child with a recessive trait if both parents are heterozygous for the trait?

25%

The hormone that induces labor and controls labor via a positive feedback mechanism is:

Oxytocin

The first major event of organogenesis is:

Neurulation

All of the following can be considered male secondary sex characteristics except the ________.

development of testes as opposed to ovaries

Which of the following is a newborn's source of energy for the first few days?

Fat

During which stage of labor is the fetus delivered?

Expulsion Stage

Which of the following structures makes up most of the male urethral length?

Spongy urethra

Extrachromosomal inheritance involves genes passed on by the mother's:

mitochondria.

Heterozygous individuals that can pass on recessive, abnormal conditions are referred to as:

Carriers

The surge in LH that occurs during the middle of the ovarian cycle triggers:

Ovulation

The muscular wall of the uterus is called the:

Myometrium

What hormone is responsible for the secondary sex characteristics found in women?

Estrogen

A change in the genetic structure of a gene is called:

Mutation

The reason why the testes are suspended in the scrotum is:

to provide for a cooler temperature.

Implantation involves ________.

embedding of the blastocyst in the uterine wall

A female infant is born with several hundred oocytes, each one genetically unique. This is due to ________.

independent assortment and random crossover

Cells on the dorsal surface of the two-layered embryonic disc migrate to form a raised groove known as the ________.

Primitive Streak

Alternative forms of genes are called:

Alleles

Sex chromosomes of a normal male are ________.

XY

The outermost embryonic membrane is the:

Chorion

A person without a Y chromosome will:

always show female characteristics.

Occasionally three polar bodies are found clinging to the mature ovum. One came from an unequal division of the ovum, but from where did the other two arise?

The first polar body has also divided to produce two polar bodies.

The appearance of freckles is considered:

The Phenotype

If a male inherits a sex-linked gene for color blindness:

it will always be expressed.

Sperm are produced in the:

seminiferous tubules.

The formation of endodermal and ectodermal germ layers occurs at ________.

Gastrulation

Human egg and sperm are similar in that ________.

they have the same number of chromosomes

A person who inherits the A and the O blood type alleles will possess which blood type?

A

Neural tissue is formed by the ________.

Ectoderm

Which hormone produced by the placenta causes the mother's pubic symphysis to loosen and widen?

Relaxin

The sperm's acrosome:

contains enzymes.

After fertilization the zygote goes through a rapid period of cell divisions called:

Cleavage

Prolactin causes:

milk production by the breast tissue.

Males tend to inherit more sex-linked conditions because:

there is no corresponding allele on their Y chromosomes.

Which is the most correct sequence of sperm flow in the male duct system?

Seminiferous tubules, epididymis, vas deferens, ampulla, ejaculatory duct, urethra

Characteristics of the mature sperm include the ________.

presence of Y chromosomes in approximately half the sperm

Genetic variation is NOT enhanced through:

Mitosis

Amy's hand was exposed to X rays. A gene in a skin cell of her hand mutated. This mutant gene will ________.

replicate itself when the cell divides but will not be passed on to Amy's offspring

Given the information in Figure 29.1, what would be the genotype of the offspring designated by the blank square?

gg