Exam 20: Development and Inheritance

In humans,the 22 pairs of chromosomes,which contain most of the genes that affect somatic characteristics such as hair color and skin pigmentation,are called

The chorionic villi

If an individual carries two different alleles of the same gene,he or she is ________ for the trait determined by that gene.

Figure 20-1 Events in Implantation Use Figure 20-1 to identify the labeled part. -Label I represents which of the following structures?

In polygenic inheritance,

A blastocyst is

If an X-carrying sperm fertilizes an egg,the resulting zygote will be

The division of the zygote into two blastomeres occurs during

Figure 20-1 Events in Implantation Use Figure 20-1 to identify the labeled part. -Label K represents which of the following structures?

An individual who is homozygous dominant for a trait would be represented as

Which extraembryonic structure is created as migrating mesodermal cells form a layer beneath the trophoblast,separating it from the blastocoele?

In which of the following does the individual carry the sex chromosome pattern XXY and is a male?

Which of the following forms when blood vessels form in the chorion,around the periphery of the blastocyst?

The extraembryonic membrane that contains fluid that surrounds and cushions the developing embryo and fetus is known as the

A(n)________ allele will always be expressed regardless of what the other allele happens to be.

Figure 20-1 Events in Implantation Use Figure 20-1 to identify the labeled part. -Label G represents which of the following structures?

Regarding the growth spurt in girls in the United States,the growth rate is maximal between the ages of

The yolk stalk and body stalk fuse during week five,forming the

During implantation,

The study of the development of the human organism during the first two months after fertilization is called