Which of the Following Is Correct Regarding Chromosomes

question 140

Multiple Choice

Which of the following is correct regarding chromosomes?

• A)At conception, the fertilized embryo has 48 chromosomes, 24 from the female egg and 24 from the male sperm.
• B)The mother of an embryo always contributes a Y chromosome and the father always contributes an X chromosome.
• C)Down syndrome results when chromosome 21 is present in triplicate instead of as the usual pair.
• D)Chromosomes have no relationship to deoxyribonucleic acid (DNA).

---

Definitions:

Subsidence

The process by which the earth's surface sinks or lowers, often due to natural underground material movement or removal of groundwater.

Average Gradient

The average gradient refers to the rate of elevation change over a particular distance, often used in geographical and hydrological analysis to describe slopes.

Base Level

The lowest point to which erosion by running water can lower the landscape, ultimately the sea level or lake level where rivers end.

Base Level

The lowest point to which a river can erode its channel, often sea level for rivers that flow directly into the oceans, but can be a lake or resistant rock layer for other rivers.