what is the difference between a homozygous recessive genotype and a homozygous dominant genotype

ATI TEAS 7

ATI TEAS 7 science review

1. What is the difference between a homozygous recessive genotype and a homozygous dominant genotype?

A. Both have the same phenotype, but different genotypes.
B. Both have the same genotype, but different phenotypes.
C. Homozygous recessive has two dominant alleles, while homozygous dominant has two recessive alleles.
D. Homozygous recessive has two identical recessive alleles, while homozygous dominant has two identical dominant alleles.

Correct answer: D

Rationale: - Homozygous recessive genotype refers to an individual having two identical recessive alleles for a particular gene (e.g., rr for a trait where r represents the recessive allele). - Homozygous dominant genotype refers to an individual having two identical dominant alleles for a particular gene (e.g., RR for a trait where R represents the dominant allele). - The difference between the two genotypes lies in the specific alleles present in each case, with homozygous recessive having two recessive alleles and homozygous dominant having two dominant alleles. - This genetic difference results in different phenotypes being expressed, as the dominant allele typically masks the expression of the recessive allele in heterozygous individuals.

2. Which of the following are the abdominal quadrants?

A. RUQ, RLQ, LLQ, LUQ
B. RUQ, LUQ, RLQ, LLQ
C. LUQ, RUQ, LLQ, RLQ
D. LLQ, LUQ, RUQ, RLQ

Correct answer: B

Rationale: The correct answer is B: RUQ, LUQ, RLQ, LLQ. The four abdominal quadrants are named as follows: Right Upper Quadrant (RUQ), Left Upper Quadrant (LUQ), Right Lower Quadrant (RLQ), and Left Lower Quadrant (LLQ). These quadrants are used in healthcare to describe specific areas of the abdomen during assessments and discussions related to abdominal anatomy and pathology. Choices A, C, and D are incorrect because they do not follow the standard order of the abdominal quadrants.

3. Which statement accurately describes the electron cloud model of the atom?

A. Electrons precisely orbit the nucleus in defined paths.
B. Electrons occupy specific energy levels around the nucleus with varying probabilities.
C. Electrons are clustered tightly within the nucleus.
D. Electrons move randomly throughout the entire atom.

Correct answer: B

Rationale: The electron cloud model of the atom describes electrons as occupying specific energy levels around the nucleus with varying probabilities. This model does not suggest that electrons precisely orbit in defined paths as stated in option A. It acknowledges the wave-like behavior of electrons and their uncertainty in position, which is not accounted for in options C and D. Option C is incorrect as electrons are not clustered tightly within the nucleus but exist in the space surrounding the nucleus. Option D is incorrect as electrons do not move randomly throughout the entire atom but have specific probabilities of being found in different regions based on their energy levels. Therefore, option B is the most accurate description of the electron cloud model of the atom.

4. When unpolarized light passes through a polarizing filter, the intensity of the transmitted light is:

A. Completely absorbed
B. Reduced by half
C. Unaffected
D. Doubled

Correct answer: B

Rationale: When unpolarized light passes through a polarizing filter, the filter only allows light waves oscillating in a specific direction to pass through while blocking light waves oscillating in other directions. Since unpolarized light consists of light waves oscillating in all possible directions, when it passes through a polarizing filter, only half of the light waves (those oscillating in the direction allowed by the filter) are transmitted. As a result, the intensity of the transmitted light is reduced by half. Choice A is incorrect because the light is not completely absorbed; choice C is incorrect because the polarizing filter affects the transmitted light; and choice D is incorrect because the intensity does not double, but rather decreases by half due to the selective transmission of light waves in a specific direction by the polarizing filter.

5. Where does gas exchange take place in the lungs?

A. Bronchi
B. Trachea
C. Alveoli
D. Pleura

Correct answer: C

Rationale: Gas exchange in the lungs occurs in the alveoli. Alveoli are tiny air sacs where oxygen from inhaled air diffuses into the bloodstream, and carbon dioxide from the blood diffuses into the alveoli to be exhaled. The bronchi are the main airways that branch off from the trachea, which is the windpipe connecting the larynx to the bronchi. The pleura is a membrane surrounding the lungs and lining the chest cavity, providing protection and lubrication for the lungs but not directly involved in gas exchange.