In which of these is a structure called an ovarypresent?
D. all of these
Important in the process of natural selection, ________creates a unique combination of genes, some of which may allow a new offspring to better survive in a changing environment
A. sexual reproduction
Members of Homo sapiens differ from other mammals (although perhaps not from other hominins) in this aspect of sexuality:
D. A and C
The number of Down Syndrome births (per 1000) for amother of age 37 ________ by the time a prospective mother reaches age 47
Police investigators analyze blood left at a crime scene without a body present. The investigators can eliminatea certain half of the population of all people as the potential victim if they look for ________ in the blood samples.
C. Barr bodies
The hormone testosterone affects which of these?
A. the entire body
Common to both males and females during puberty is a sequence of hormonal and glandular events. Which of these is found only in females?
What do the testes contribute to seminal fluid?
B. sperm cells
Human sperm, certain prokaryotes and protists all share:
B. a flagellum
Where has knowledge from subatomic physics and the decay rates of isotopes been of value in modern medicine?
B. cancer therapy
If you are a female, how old are your egg cells?
C. as old as you are
The culturally-influenced wearing of tight-fitting pants has been tied to human
A. male infertility
Prevention of pregnancy by continuing to nurse is
B. a myth
Hormonal regulation of ovulation is
A. an effective means of birth-control
Which of these is a causal agent of STDs?
D. all are
The most commonly reported STD
The formation of a new individual by the union of twosex cells:
B. sexual reproduction
Zygotes contain ________ of chromosomes
B. two sets
In order that each gamete have on set of chromosomes, this process occurs to create the haploid gametes:
How many chromosomes exist in the average adult human?
How many chromosomes are involved in the determination of the sex of an individual?
Which chromosome is primarily concerned with determining male sexual differentiation?
During fetal development, the differentiation of cellsinto gonads happens at about week number ________.
Puberty is generally reached by ________ before________.
B. girls; boys
The lining of the uterus is maintained by the hormone:
The final structure through which sperm must pass before exiting the penis:
This gland is a contributor to semen but later in life can cause cancer in some 75% of men over 65 years of age:
When are oocytes formed?
A. before birth
The same hormones that prepare the uterus to receive the embryo
A. prepare the breasts for milk production
The use of fertility drugs or other techniques often results in this side-effect which may or may not be desired by the expectant parents:
B. the birth of twins, triplets or more children
One sperm out of millions fertilizes an egg; the remainder
D. produce enzymes that digest the mucus barrierbetween the egg and the successful sperm
The nutritional needs of the human embryo are met through the:
Which of these can cross the placental barrier and into the developing embryo?
D. all of these
About what percentage of births in the United States occur by cesarean section?
Preparation of the mother's body for labor is accomplished by the release of a hormone called:
Contraceptive methods have been employed by human societies since at least the time of: