TEAS Practice Test Science

Correct Answer: B

Rationale: The correct answer is B: Meiosis Prophase I. Crossing over occurs during Prophase I of meiosis, specifically during the substage called pachytene. This is when homologous chromosomes pair up and exchange genetic material. This process creates genetic diversity among offspring. Choice A, Mitosis Prophase, is incorrect because crossing over does not occur during mitosis, as homologous chromosomes do not pair up in mitosis. Choice C, Meiosis Prophase II, is incorrect because crossing over only occurs during Prophase I, not Prophase II. Choice D, Interphase, is incorrect because crossing over does not occur during interphase, as it is a phase where the cell prepares for division and DNA replication occurs.

Correct Answer: C

Rationale: The correct answer is C: Pluripotent stem cells. Pluripotent stem cells can differentiate into many different cell types but cannot form a complete organism. They have the ability to give rise to cells of all three germ layers. Totipotent stem cells (A) can form a complete organism, including both embryonic and extra-embryonic tissues. Multipotent stem cells (B) can develop into a limited range of cell types. Hematopoietic stem cells (D) specifically give rise to blood cells and their progenitors, so they are more specialized compared to pluripotent stem cells.

Correct Answer: A

Rationale: The independent variable is what the researcher manipulates to observe its effect on the dependent variable. In this study, the botanist is testing if temperature affects root growth. Therefore, the independent variable is temperature (choice A). The botanist will change the temperature levels to see how it influences root growth. Choices B, C, and D are not the independent variable as the botanist is not directly manipulating seedlings, light, or root length to study the effect on root growth.

Correct Answer: B

Rationale: The correct answer is B: Meiosis Prophase I. Crossing over occurs during Prophase I of meiosis, specifically during the substage called pachytene. This is when homologous chromosomes pair up and exchange genetic material. This process creates genetic diversity among offspring. Choice A, Mitosis Prophase, is incorrect because crossing over does not occur during mitosis, as homologous chromosomes do not pair up in mitosis. Choice C, Meiosis Prophase II, is incorrect because crossing over only occurs during Prophase I, not Prophase II. Choice D, Interphase, is incorrect because crossing over does not occur during interphase, as it is a phase where the cell prepares for division and DNA replication occurs.

Correct Answer: B

Rationale: The correct answer is B: Fibrous. Fibrous joints connect bones of the skull with fibrous tissue, providing stability and limited movement. Synovial joints (Choice A) have a joint cavity with synovial fluid for movement but aren't found in the skull. Cartilaginous joints (Choice C) connect bones with cartilage and allow slight movement, not commonly found in the skull. Ball-and-socket joints (Choice D) allow the widest range of motion and are not present in the skull. Therefore, the fibrous joint is the most suitable type for connecting the bones of the skull.