1. Which term describes the functional unit of a skeletal muscle responsible for muscle contraction?

A. Myofibril
B. Sarcomere
C. Tendon
D. Myoglobin

Correct answer: b

Rationale: The correct answer is B: Sarcomere. A sarcomere is the functional unit of a skeletal muscle responsible for muscle contraction. It is made up of overlapping filaments of actin and myosin proteins. Myofibrils are long, cylindrical structures within muscle cells that contain sarcomeres. Tendons are tough bands of fibrous connective tissue that connect muscles to bones and facilitate movement. Myoglobin is a protein found in muscle cells that stores oxygen for muscle use during exercise. Therefore, the sarcomere is specifically responsible for muscle contraction, making it the correct answer in this question.

2. Which property of a wave remains constant when the wave enters a different medium?

A. Frequency
B. Wavelength
C. Amplitude
D. Speed

Correct answer: d

Rationale: The speed of a wave remains constant when it enters a different medium, provided the conditions are unchanged.

3. 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 intensity of the transmitted light is reduced by half. This is because a polarizing filter only allows light waves oscillating in one plane to pass through while blocking the other perpendicular plane. Unpolarized light consists of waves oscillating in all possible planes, so when it passes through the polarizer, only half of the light waves aligned with the filter's polarization direction can transmit through. As a result, the intensity of the transmitted light is reduced by half as only a portion of the original light waves can pass through the filter.

4. What is the building block of RNA?

A. Amino acid
B. Nucleotide
C. Protein
D. Fatty acid

Correct answer: B

Rationale: Rationale: A) Amino acid: Amino acids are the building blocks of proteins, not RNA. B) Nucleotide: Nucleotides are the building blocks of RNA. A nucleotide consists of a nitrogenous base (adenine, guanine, cytosine, or uracil in RNA), a sugar (ribose in RNA), and a phosphate group. C) Protein: Proteins are made up of amino acids, not nucleotides. D) Fatty acid: Fatty acids are components of lipids, not RNA.

5. A major factor influencing the distribution of organisms geographically is:

A. The availability of specific types of food sources
B. olerance of organisms to different temperature ranges
C. Competition for mates within the same species
D. All of the above

Correct answer: D

Rationale: Rationale: The distribution of organisms geographically is influenced by a variety of factors, including the availability of specific types of food sources (option A). Organisms need to have access to suitable food sources in order to survive and thrive in a particular area. Additionally, the tolerance of organisms to different temperature ranges (option B) is crucial as temperature can greatly impact where certain species can live. Organisms must be able to withstand the temperature conditions of a given environment to survive there. Competition for mates within the same species (option C) can also play a role in the distribution of organisms, as it can affect population sizes and dynamics in different areas. Therefore, all of these factors - food availability, temperature tolerance, and competition for mates - collectively influence the distribution of organisms geographically.

6. What is the ethical concern surrounding genetic engineering?

A. Risk of introducing new diseases
B. Potential for misuse and discrimination
C. Unforeseen consequences on ecosystems
D. All of the above

Correct answer: D

Rationale: Rationale: A) Risk of introducing new diseases: Genetic engineering involves manipulating the genetic material of organisms, which can potentially lead to the creation of new diseases or the spread of existing ones in unintended ways. This risk raises ethical concerns about the potential harm to human health and the environment. B) Potential for misuse and discrimination: Genetic engineering technologies can be misused for purposes such as creating biological weapons or enhancing certain traits in individuals, leading to discrimination based on genetic makeup. This raises ethical concerns about fairness, justice, and the potential for societal harm. C) Unforeseen consequences on ecosystems: Genetic engineering can have unintended consequences on ecosystems, such as disrupting natural balances or harming biodiversity. These unforeseen impacts raise ethical concerns about the responsibility of scientists and policymakers to consider the long-term effects of genetic modifications on th