Correct Answer: (4) ribosomes

Translation is the process wherein the messenger RNA becomes protein. Translation begins the starting end of the mRNA strand attaches to a ribosome. Ribosome is a cell organelle constructed in the nucleolus (a part of the nucleus), consisting of two subunits and functioning as the site of protein synthesis in the cytoplasm.

Incorrect Answers:

Cell membrane or plasma membrane is the membrane at the boundary of every cell that acts as selective barrier, thereby regulating the cell's chemical composition.

Chloroplast is an organelle found only in plants and photosynthetic protests that absorbs sunlight and uses it to drive the synthesis of organic compounds from carbon dioxide and water.

Mitochondrion (plural, mitochondria) is an organelle in eukaryotic cells that serves as the site of cellular respiration.

Correct Answer: (3) the digestion of minerals

This process is particularly called nitrogen fixation, wherein the bacteria degrade organic matter, releasing fixed nitrogen for reuse by other organisms.

Incorrect Answers:

Homeostasis refers to the body's mechanism to maintain a constant environment.

During photosynthesis, carbon dioxide and water are converted into glucose and water by the use of solar energy.

Correct Answer: (4) D and E

Digestion is the process of breaking down food into molecules small enough for the body to absorb. Based on the pattern of structures D and E, these are the broken down components of structure A.

Incorrect Answers:

Structures A, C, and B are macromolecules which have not been broken down into smaller molecules.

Correct Answer: (2) digestion→diffusion→cellular respiration

When food is digested, most of it is transformed into simpler molecules that can be absorbed by the body. This simpler molecules diffuse into the cells of the body and enters the mitochondria, which is the cite of cellular respiration. Respiration yields ATP which is the chemical form of energy which will be used up the muscle cells for locomotion and other energy-requiring reactions.

Correct Answer: (4) The ability to fight disease caused by he pathogen will increase due to antibody production

Vaccines are biological agent s prepared to improve immunity to certain diseases. They usually contain a weakened pathogen which will stimulate the immune system, recognize it as harmful and form an antibody against it so the next time that the system will encounter it again, it will be destroyed spontaneously to prevent multiplication in the host's body. Antibodies are proteins produced by the plasma cell, a specialized type of white blood cell.

Correct Answer: (3) maintenance of a dynamic equilibrium through detection and response to stimuli

Guard cells are specialized epidermal plant cells that form the boundaries of the stomata. They regulate the speed of transpiration by opening and closing the stomata and so preventing excessive water loss.

Incorrect Answers:

Nerve cells and receptor sites are found in more complex organisms like animals.

The guard cells have no direct effect on the rate of growth of the plant.

Water is an abiotic factor.

Correct Answer: (1) presence of tubes to transport materials into and out the colony

These tubes serve as their transport system and probably aid their communication process.

Incorrect Answers:

Options 2, 3, and 4 are false statements based on the selection given.

Correct Answer: (3) They cause major infection problems in hospitals.

Pseudomonas aeruginosa is an opportunistic pathogen, exploiting some break in the host defenses to instigate an infection. It is a well-known opportunistic pathogen of humans. The bacterium almost never infects uncompromised tissues, yet there is hardly any tissue that it cannot contaminate if the tissue defenses are neglected in some way. It causes urinary tract infections, respiratory system infections, dermatitis, soft tissue infections, bacteremia, bone and joint infections, gastrointestinal infections and different systemic infections, predominantly in patients with severe burns and in cancer and AIDS patients who are immunosuppressed. Pseudomonas aeruginosa infection is a severe predicament in patients hospitalized with cancer, cystic fibrosis, and burns.

Correct Answer: (2) circulatory and excretory systems

Just like the tubes in the biofilms, circulatory systems function for the transport of nutrients; while excretory systems remove metabolic wastes from the body.

Incorrect Answers:

Muscular system functions for locomotion of the body and its body parts. The nervous system is responsible for the transmission of impulses and reactions to stimuli.

Digestive system functions for the conversion of food into simpler forms that can be used up by the body. Endocrine system is responsible for the release of hormones necessary for the body functions.

Reproductive system functions for the production of gametes for the propagation of the species. Respiratory system is responsible for the intake of oxygen and release of carbon dioxide to supply oxygen to the different cells of the body.

Correct Answer: (1) Nerve cell X is releasing receptor molecules.

Substance A is a neurotransmitter. It is a chemical messenger released from the synaptic terminal of a neuron (nerve cell X) at a chemical synapse that diffuses across the synaptic cleft and binds to and stimulates the post synaptic cell (nerve cell Y).

Correct Answer: (2)

The drug's shape must fit into the shape of the neurotransmitter so that the neurotransmitter will not anchor with the receptor of the post-synaptic neuron. With this action, the function of the neurotransmitter will be impeded.

Incorrect Answers:

Other shapes will not fit into the shape of the neurotransmitter and thus fail to block the action of the neurotransmitter.

Correct Answers:

A (an organ in the human body where molecules diffuse into the blood)-lungs

B (specific molecule that diffuse into the blood at this organ)-oxygen

Blood arrives at lung via the pulmonary artery. As blood enters the capillary beds round the alveoli, carbon dioxide diffused from the blood to the air within the alveoli. Oxygen in the air dissolves in the fluid that coats the epithelium and diffuses across the surfcee and into the capillary. The blood leaves the lungs in the pulmonary veins. After returning to the heart, this blood is pumped through the systemic circuit.

Correct Answer: Internal control of the body

The internal control of the body is directed by two systems: the nervous system and he endocrine system. The endocrine system is made up of a series of glands that release chemicals directly into the blood stream. On the other hand, the nervous system is responsible for the transmission of impulses and formation of responses to stimuli. Coordination is needed between these two organ systems. The hypothalamus is the portion of the brain that controls the pituitary gland. These organs are connected by nerves and blood vessels. The hypothalamus sends messages to the pituitary, which then releases its own chemicals, or stimulates other glands to release theirs.

When pathogens like parasites, fungi, bacteria, and viruses invade the body, the coordination between the nervous and endocrine systems might be interrupted, and thus the internal control  of the body is affected.