which cell organelle is the site of protein synthesis.
This biology question covers important biological concepts and processes. The step-by-step explanation below helps you understand the underlying mechanisms and reasoning.
ScanSolve AI Answer
Step 1: Analyze Question 1.
The question asks which cell organelle is the site of protein synthesis.
A) Nucleus* contains genetic material and controls cell activities, but protein synthesis occurs outside it.
B) Lysosome* contains digestive enzymes.
C) Ribosome* is the primary site of protein synthesis (translation).
D) Golgi apparatus* modifies, sorts, and packages proteins and lipids.
The correct answer is ribosome.
Answer:* C
Step 2: Analyze Question 2.
The question asks to identify a characteristic feature of mammals.
A) Possession of mammary glands* is a defining characteristic of mammals, used for feeding young.
B) Possession of opposable thumbs* is characteristic of primates, a subgroup of mammals, not all mammals.
C) Production of thick hairs on the body* is not unique to mammals; some reptiles and insects also have hair-like structures, and not all mammals have thick hair.
D) Presence of lungs for gas exchange* is common to many vertebrates, not exclusive to mammals.
The correct answer is possession of mammary glands.
Answer:* A
Step 3: Analyze Question 3.
The question asks to identify a characteristic of active transport.
Active transport moves substances against their concentration gradient, requiring energy.
A) Active transport differs from simple diffusion and osmosis* because it requires energy and moves against a gradient, unlike passive diffusion and osmosis.
B) A selectively permeable membrane is essential* for both active and passive transport.
C) Energy in the form of ATP* is required for active transport. This is a key characteristic.
D) A high concentration of substances is the condition against* which active transport often works, not a characteristic of the process itself.
Both A and C are true. However, C describes the mechanism of active transport (energy requirement), which is more fundamental than just stating it differs from other processes. Given the options, the requirement for ATP is a direct characteristic. Let's re-evaluate A. "Active transport differs from simple diffusion and osmosis in that it requires..." This is a true statement, but C is a more direct characteristic of active transport itself. If active transport requires energy, it inherently differs from passive processes.
Let's consider the options again.
A) "Active transport differs from simple diffusion and osmosis in that it requires..." - This is a true statement about its nature.
C) "Energy in the form of ATP." - This is the source of energy required.
Both are strong contenders. However, the question asks for "a characteristic feature." The requirement for ATP is a direct, internal characteristic of the process. The fact that it "differs" from other processes is a comparative statement.
Let's assume the question is looking for a direct property.
Answer:* C
Step 4: Analyze Question 4.
The question asks how blood is classified as a type of tissue.
Blood consists of cells (red blood cells, white blood cells, platelets) suspended in an extracellular matrix (plasma). This structure is characteristic of connective tissue.
A) Connective tissue* is the correct classification for blood.
B) Epidermal tissue* forms the outer layer of skin.
C) Nervous tissue* forms the brain, spinal cord, and nerves.
D) Muscular tissue* is responsible for movement.
The correct answer is connective tissue.
Answer:* A
Step 5: Analyze Question 5.
The question asks to identify a correct difference between mitosis and meiosis.
Let's examine the table:
Mitosis:
A) Produces genetically identical daughter cells. (Correct)
B) Occurs in reproductive cells. (Incorrect, occurs in somatic cells)
C) Halves the chromosome number of the parent cell. (Incorrect, maintains chromosome number)
D) It results in variation in offspring. (Incorrect, no variation)
Meiosis:
A) Produces genetically identical daughter cells. (Incorrect, produces genetically different* cells)
B) Occurs in reproductive cells. (Correct)
C) Doubles the chromosome number of the parent cell. (Incorrect, halves chromosome number)
D) There is no variation in offspring. (Incorrect, produces variation)
Let's re-read the options carefully, looking for a correct pair of differences.
The table format is:
| Mitosis | Meiosis |
| :------ | :------ |
| A) It produces haploid genetically identical daughter cells. | It produces diploid genetically identical daughter cells. |
| B) It occurs in somatic cells. | It occurs in reproductive cells. |
| C) It halves the chromosome number of the parent cell. | It doubles the chromosome number of the parent cell. |
| D) It results in variation in offspring. | There is no variation in offspring. |
Let's evaluate each row as a complete statement of difference:
A) Mitosis produces diploid genetically identical cells. Meiosis produces haploid genetically different* cells. So, "haploid" for mitosis is incorrect, and "diploid" for meiosis is incorrect. This row is incorrect.
B) Mitosis occurs in somatic cells. Meiosis occurs in reproductive* cells (to form gametes). This row presents a correct difference.
C) Mitosis maintains the chromosome number. Meiosis halves* the chromosome number. Both statements in this row are incorrect.
D) Mitosis produces no variation. Meiosis produces variation*. Both statements in this row are incorrect.
Therefore, option B correctly states a difference.
Answer:* B
Step 6: Analyze Question 6.
The question asks what happens during ossification.
Ossification (or osteogenesis) is the process of bone formation.
A) Bones fracture more easily* is not a direct event of ossification; it's a consequence of weakened bones.
B) Bone is replaced by cartilage* is incorrect; cartilage is replaced by bone.
C) Cartilage is replaced by bone* is the correct description of endochondral ossification, a major type of bone formation.
D) Bones lose mineral and mass* describes osteoporosis or bone demineralization, not ossification.
The correct answer is cartilage is replaced by bone.
Answer:* C
Step 7: Analyze Question 7.
The question asks which type of muscle tissue is striated and under voluntary control.
A) Cardiac muscle is striated but involuntary*.
B) Smooth muscle is involuntary and non-striated*.
C) Skeletal muscle is both striated and voluntary*.
D) Visceral muscle* is another term for smooth muscle, so it's involuntary and non-striated.
The correct answer is skeletal muscle.
Answer:* C
Step 8: Analyze Question 8.
The question asks to identify the joint which is synovially matched with its location in the human body.
A) Hinge joint - hip*: The hip is a ball-and-socket joint. The knee and elbow are hinge joints.
B) Suture joint - elbow*: The elbow is a hinge joint. Suture joints are immovable joints found in the skull.
C) Ball-and-socket joint - shoulder*: The shoulder is indeed a ball-and-socket joint, allowing for a wide range of motion.
D) Condyloid joint - knee*: The knee is primarily a hinge joint, though it has some rotational movement. A condyloid joint allows movement in two planes (e.g., wrist).
The correct match is ball-and-socket joint - shoulder.
Answer:* C
Step 9: Analyze Question 9.
The question asks which of the following is the correct path of a nerve impulse in a typical reflex arc.
A reflex arc typically involves:
1. Receptor: Detects the stimulus.
2. Sensory neuron (afferent neuron): Transmits impulse from receptor to CNS.
3. Relay neuron (interneuron): In the CNS, connects sensory to motor neuron.
4. Motor neuron (efferent neuron): Transmits impulse from CNS to effector.
5. Effector: Muscle or gland that responds.
Let's check the options:
A) Effector $\rightarrow$ sensory neuron $\rightarrow$ relay neuron $\rightarrow$ motor neuron $\rightarrow$ receptor*: Incorrect order.
B) Receptor $\rightarrow$ sensory neuron $\rightarrow$ relay neuron $\rightarrow$ motor neuron $\rightarrow$ effector*: This is the correct sequence.
C) Effector $\rightarrow$ sensory neuron $\rightarrow$ relay neuron $\rightarrow$ receptor $\rightarrow$ motor neuron*: Incorrect order.
D) Receptor $\rightarrow$ motor neuron $\rightarrow$ relay neuron $\rightarrow$ sensory neuron $\rightarrow$ effector*: Incorrect order.
The correct answer is B.
Answer:* B
Step 10: Analyze Question 10.
The diagram shows the structure of a motor neuron. Part labeled 3 is the axon. The question asks for the role of part 3 (axon) in nerve impulse transmission.
The axon's primary role is to transmit the nerve impulse (action potential) away from the cell body towards the axon terminals. Myelin sheath (if present) around the axon speeds up this transmission.
A) Produces neurotransmitters*: Neurotransmitters are produced in the cell body and stored in axon terminals.
B) Insulates the axon against heat loss*: While the myelin sheath (part of the axon structure) provides insulation, its primary role is to speed up impulse transmission, not primarily against heat loss.
C) Speeds up the transmission of a nerve impulse by boosting its strength*: The axon transmits the impulse; the myelin sheath speeds it up, but it doesn't "boost its strength" in the sense of increasing the amplitude of the action potential. Action potentials are all-or-nothing.
D) Generates action potential: The action potential is typically generated at the axon hillock (junction of cell body and axon), not along the entire axon. The axon conducts* the action potential.
Let's re-evaluate the options, as none seem perfectly phrased for the axon's role in isolation. However, considering the overall function of the axon and its associated structures (like myelin), option C is the closest to describing its role in transmission speed. The myelin sheath, which is part of the axon structure, significantly speeds up transmission. If "part 3" refers to the myelinated axon, then speeding up transmission is a key function.
Let's reconsider the options in the context of a multiple-choice question where one answer is "best."
A) Neurotransmitters are released from axon terminals, but produced in the cell body.
B) Insulation is a function of myelin, but "against heat loss" is not the primary biological reason.
C) "Speeds up the transmission of a nerve impulse" is a major function of a myelinated axon. "by boosting its strength" is inaccurate for action potentials, but the first part is correct.
D) Action potentials are generated at the axon hillock, not the entire axon.
Given the options, C is the most plausible, focusing on the speed of transmission, which is a critical function of the axon, especially if myelinated.
Answer:* C
Step 11: Analyze Question 11.
The question asks what the function of the Eustachian tube (auditory tube) in the human ear is.
The Eustachian tube connects the middle ear to the nasopharynx.
A) Protects the inner ear from damage*: This is not its primary function.
B) Transmits sound waves in the brain*: Sound waves are transmitted through the ear structures to the brain, but the Eustachian tube's role is not direct transmission of sound waves to the brain.
C) Equalizes pressure on both sides of the eardrum*: This is the primary function of the Eustachian tube. It opens to allow air pressure in the middle ear to match the external atmospheric pressure, preventing damage to the eardrum and allowing it to vibrate freely.
D) Generates action potential*: This is a function of neurons, not the Eustachian tube.
The correct answer is to equalize pressure on both sides of the eardrum.
Answer:* C
