Communication, Homeostasis and Energy: Master Biology for Year 13 Exams

Question 1

Which component of a neuron conducts electrical signals?

Accepted Answer

Axon

Answer

Dendrite

Answer

Cell Body

Answer

Myelin Sheath

Question 2

How does negative feedback contribute to maintaining a stable internal environment in organisms?

Accepted Answer

Negative feedback opposes changes that move the variable away from the set point.

Answer

Negative feedback amplifies changes that move the variable away from the set point.

Answer

Negative feedback is exclusive to animal organisms.

Question 3

Which neurotransmitter is responsible for conveying pain signals from the body to the brain?

Accepted Answer

Substance P

Answer

Epinephrine

Answer

Dopamine

Question 4

Describe the contrasting mechanisms of hormone secretion in the anterior and posterior pituitary glands.

Accepted Answer

Anterior pituitary: synthesizes and secretes its own hormones; Posterior pituitary: stores and releases hormones produced by the hypothalamus.

Answer

Anterior pituitary: stores and releases hormones produced by the hypothalamus; Posterior pituitary: synthesizes and secretes its own hormones.

Answer

Both the anterior and posterior pituitary glands store and release hormones produced by the hypothalamus.

Answer

Both the anterior and posterior pituitary glands synthesize and secrete their own hormones.

Question 5

Question:

Define homeostasis and explain how negative and positive feedback mechanisms work together to maintain a stable internal environment in living organisms.

Accepted Answer

Homeostasis is the maintenance of a stable internal environment despite external changes.

Accepted Answer

Positive feedback mechanisms amplify changes, while negative feedback mechanisms counteract changes.

Accepted Answer

Negative feedback mechanisms return the internal environment to its set point value.

Answer

Homeostatic mechanisms help organisms maintain stability but do not enable adaptation to new environmental conditions.

Question 6

Describe how negative feedback mechanisms contribute to maintaining homeostasis in living organisms. Support your answer with specific examples.

Accepted Answer

Negative feedback mechanisms involve releasing hormones or signals that counteract the initial change, restoring the system to equilibrium.

Answer

Negative feedback mechanisms intensify the initial change, causing a greater deviation from the set point.

Answer

Negative feedback mechanisms are exclusive to mammals and only regulate body temperature.

Answer

Negative feedback mechanisms always return the system to its original set point, regardless of the initial stimulus.

Question 7

Which hormone is released by the pituitary gland to stimulate the adrenal glands in response to stress?

Accepted Answer

Adrenocorticotropic hormone (ACTH)

Answer

Thyroid-stimulating hormone (TSH)

Answer

Follicle-stimulating hormone (FSH)

Answer

Antidiuretic hormone (ADH)

Question 8

Which of the following is an example of a positive feedback loop?

Accepted Answer

Stimulation of milk production

Answer

Regulation of blood glucose levels

Answer

Control of body temperature

Answer

Regulation of the menstrual cycle

Question 9

In which part of the chloroplast does the light-dependent reaction of photosynthesis take place?

Accepted Answer

Thylakoid membrane

Answer

Stroma

Answer

Cytoplasm

Answer

Chloroplast envelope

Question 10

Which of the following is a product of glycolysis?

Accepted Answer

Pyruvate

Answer

Glucose

Answer

ATP

Answer

Carbon dioxide

Question 11

Which neurotransmitter is released by the sympathetic nervous system during the "fight-or-flight" response?

Accepted Answer

Epinephrine

Answer

Acetylcholine

Answer

Dopamine

Answer

Serotonin

Question 12

Where does protein synthesis primarily occur in eukaryotic cells?

Accepted Answer

Ribosomes

Answer

Nucleus

Answer

Mitochondria

Answer

Golgi apparatus

Question 13

Which neurotransmitter is primarily responsible for the physiological effects associated with the "fight-or-flight" response?

Accepted Answer

Norepinephrine

Answer

Serotonin

Answer

Dopamine

Answer

GABA

Question 14

Which hormone is primarily responsible for regulating blood glucose levels in the body?

Accepted Answer

Insulin

Answer

Glucagon

Answer

Estrogen

Answer

Testosterone

Question 15

In plants, photosynthesis utilizes the energy from sunlight to convert specific substrates into products:

Accepted Answer

Carbon dioxide and water into glucose and oxygen

Answer

Glucose and oxygen into carbon dioxide and water

Answer

Nitrogen and hydrogen into ammonia

Answer

Oxygen and hydrogen into water

Question 16

Which organelle within eukaryotic cells is primarily responsible for cellular respiration and energy production?

Accepted Answer

Mitochondria

Answer

Ribosomes

Answer

Lysosomes

Answer

Golgi apparatus

Question 17

The process by which plants release water vapor into the atmosphere, contributing to the water cycle, is known as:

Accepted Answer

Transpiration

Answer

Diffusion

Answer

Osmosis

Answer

Guttation

Question 18

Identify the hormone that stimulates the release of digestive enzymes in the stomach, aiding in the process of digestion:

Accepted Answer

Gastrin

Answer

Insulin

Answer

Adrenaline

Answer

Thyroid hormone

Question 19

During the transmission of a nerve impulse, the generation of an action potential is primarily caused by a change in the permeability of the neuronal membrane to:

Accepted Answer

Sodium and potassium ions

Answer

Calcium and chloride ions

Answer

Water and carbon dioxide

Answer

Magnesium and sulfate ions

Question 20

Which of the following options does NOT represent a type of homeostasis, where organisms maintain a relatively stable internal environment despite external changes?

Accepted Answer

Cellular differentiation

Answer

Thermoregulation

Answer

Osmoregulation

Answer

pH regulation

Question 21

In the process of protein synthesis, which cellular component is responsible for translating the genetic code into a sequence of amino acids?

Accepted Answer

Ribosomes

Answer

Mitochondria

Answer

Chloroplasts

Answer

Golgi apparatus

Question 22

Which of the following is NOT a component of the nervous system?

Accepted Answer

Hormones

Answer

Neurons

Answer

Synapses

Answer

Nerves

Question 23

Which type of feedback loop results in the reversal of a change in a variable?

Accepted Answer

Negative feedback

Answer

Positive feedback

Answer

No feedback

Answer

Delayed feedback

Question 24

Which hormone is primarily responsible for regulating blood glucose levels?

Accepted Answer

Insulin

Answer

Glucagon

Answer

Adrenaline

Answer

Thyroxine

Question 25

What is the primary function of the respiratory system?

Accepted Answer

Exchange of gases between the blood and the environment

Answer

Regulation of body temperature

Answer

Waste excretion

Answer

Digestion

Question 26

Which of the following is a characteristic of a negative feedback loop?

Accepted Answer

Opposes the initial change

Answer

Amplifies the initial change

Answer

Requires a large initial change to trigger a response

Answer

Only occurs in multicellular organisms

Question 27

What is the role of the stomata in plants?

Accepted Answer

Exchange of gases between the plant and the environment

Answer

Water absorption from the soil

Answer

Nutrient uptake from the soil

Answer

Support for the plant

Question 28

Which of the following is a neurotransmitter?

Accepted Answer

Serotonin

Answer

Glycogen

Answer

Insulin

Answer

Hemoglobin

Question 29

What is the name of the molecule that carries genetic information?

Accepted Answer

DNA

Answer

RNA

Answer

Protein

Answer

Glucose

Question 30

Which of the following substances is NOT a neurotransmitter in the human nervous system?

Accepted Answer

Glycogen

Answer

Acetylcholine

Answer

Dopamine

Answer

Epinephrine

Question 31

The feedback loop that maintains relatively constant blood glucose levels is an example of:

Accepted Answer

Negative feedback

Answer

Positive feedback

Answer

Homeostasis

Answer

Allostasis

Question 32

Which hormone is primarily responsible for promoting growth and development in animals?

Accepted Answer

Growth hormone

Answer

Insulin

Answer

Estrogen

Answer

Testosterone

Question 33

The process by which plants utilize light energy to convert carbon dioxide and water into glucose is known as:

Accepted Answer

Photosynthesis

Answer

Respiration

Answer

Glycolysis

Answer

Chemosynthesis

Question 34

The primary hormone responsible for regulating calcium levels in the blood is:

Accepted Answer

Parathyroid hormone

Answer

Adrenaline

Answer

Insulin

Answer

Thyroid hormone

Question 35

In a negative feedback loop, which of the following is NOT a component?

Accepted Answer

Positive stimulus

Answer

Receptor

Answer

Control center

Answer

Effector

Question 36

In a negative feedback loop, how does the response typically affect the stimulus?

Accepted Answer

Opposes the stimulus

Answer

Amplifies the stimulus

Answer

Has no effect on the stimulus

Answer

Is independent of the stimulus

Question 37

Which organ secretes insulin, a hormone involved in regulating blood sugar levels?

Accepted Answer

Pancreas

Answer

Adrenal gland

Answer

Pituitary gland

Answer

Thyroid gland

Question 38

Which substance is a major product of cellular respiration?

Accepted Answer

ATP

Answer

Glucose

Answer

Oxygen

Answer

Carbon dioxide

Question 39

Which division of the nervous system is responsible for controlling involuntary bodily functions, such as heart rate and digestion?

Accepted Answer

Autonomic nervous system

Answer

Central nervous system

Answer

Peripheral nervous system

Answer

Sensory nervous system

Question 40

Within the brain, which region is primarily responsible for maintaining a stable body temperature?

Accepted Answer

Hypothalamus

Answer

Cerebellum

Answer

Medulla oblongata

Answer

Hippocampus

Question 41

In the light-dependent reactions of photosynthesis, which molecule serves as the primary electron acceptor?

Accepted Answer

NADP+

Answer

CO2

Answer

H2O

Answer

O2

Question 42

Within the cell, where does the Krebs cycle (citric acid cycle) take place?

Accepted Answer

Mitochondrial matrix

Answer

Cytoplasm

Answer

Mitochondrial inner membrane

Answer

Thylakoid membrane

Question 43

Within the electron transport chain, the primary role of NADH and FADH2 is to:

Accepted Answer

Accept electrons and transfer them to oxygen

Answer

Generate ATP through oxidative phosphorylation

Answer

Provide energy for active transport

Answer

Reduce CO2 to glucose

Question 44

Which of the following is not a function of the nervous system?

Accepted Answer

Secreting hormones

Answer

Receiving and interpreting stimuli

Answer

Controlling movement

Answer

Maintaining homeostasis

Question 45

A negative feedback loop is characterized by:

Accepted Answer

Responding to a change by reducing the stimulus

Answer

Responding to a change by increasing the stimulus

Answer

Occurring only in plants

Answer

Occurring only in animals

Question 46

In response to stress, the adrenal glands release the hormone:

Accepted Answer

Adrenaline

Answer

Insulin

Answer

Thyroxine

Answer

Estrogen

Question 47

Photosynthesis' light-dependent reactions take place in the:

Accepted Answer

Thylakoid membranes of chloroplasts

Answer

Stroma of chloroplasts

Answer

Cytoplasm of mesophyll cells

Answer

Vacuoles of guard cells

Question 48

In glycolysis, the enzyme responsible for initiating glucose breakdown is:

Accepted Answer

Hexokinase

Answer

Phosphofructokinase

Answer

Pyruvate kinase

Answer

Citrate synthase

Question 49

Diffusion is characterized by:

Accepted Answer

Moving molecules from low to high concentration

Answer

Requiring energy

Answer

Involving the movement of large molecules

Answer

Occurring only across cell membranes

Question 50

At rest, the membrane potential of a neuron is:

Accepted Answer

Negative inside the cell

Answer

Positive inside the cell

Answer

Zero

Answer

Variable depending on the neuron type

Question 51

The hormone responsible for stimulating glucose release from the liver is:

Accepted Answer

Glucagon

Answer

Insulin

Answer

Thyroxine

Answer

Estrogen

Question 52

The primary energy currency of cells is:

Accepted Answer

ATP

Answer

Glucose

Answer

NADH

Answer

FADH2

Question 53

A key function of the nervous system is to:

Accepted Answer

Detect and process sensory information

Answer

Regulate body temperature

Answer

Maintain electrolyte balance

Answer

Produce hormones

Question 54

Which hormone is primarily responsible for regulating blood sugar levels?

Accepted Answer

Insulin

Answer

Thyroxine

Answer

Adrenaline

Answer

Estrogen

Question 55

A negative feedback mechanism operates to:

Accepted Answer

Maintain a stable internal environment by counteracting changes

Answer

Amplify initial changes, leading to larger responses

Answer

Control processes through a linear progression of events

Answer

Trigger irreversible changes in the body

Question 56

During aerobic respiration, the final electron acceptor is:

Accepted Answer

Oxygen

Answer

Carbon dioxide

Answer

Hydrogen

Answer

Water

Question 57

A primary function of the respiratory system is:

Accepted Answer

Exchange of respiratory gases

Answer

Regulation of body temperature

Answer

Elimination of waste products

Answer

Absorption of nutrients

Question 58

Which hormone, secreted by the pancreas, acts to lower blood glucose levels?

Accepted Answer

Insulin

Answer

Glucagon

Answer

Adrenaline

Answer

Cortisol

Question 59

A positive feedback loop is characterized by:

Accepted Answer

Amplification of initial changes, leading to more significant responses

Answer

Counteraction of changes, maintaining stability

Answer

Linear progression of events

Answer

Irreversible alterations in physiological processes

Question 60

A patient with a high blood glucose level is experiencing hyperglycemia. Which of the following hormones would be released to help lower their blood sugar levels?

Accepted Answer

Insulin

Answer

Thyroxine

Answer

Adrenaline

Answer

Glucagon

Question 61

Which of the following is NOT a characteristic of a negative feedback loop?

Accepted Answer

Amplifies the initial stimulus

Answer

Maintains a set point

Answer

Reduces the deviation from the set point

Answer

Involves a sensor, effector, and control center

Question 62

A neuron receives a signal from another neuron at its:

Accepted Answer

Dendrites

Answer

Myelin sheath

Answer

Axon

Answer

Synaptic cleft

Question 63

Which of the following is the correct sequence of events in a typical reflex arc?

Accepted Answer

Receptor → Sensory neuron → Relay neuron → Motor neuron → Effector

Answer

Sensory neuron → Receptor → Relay neuron → Motor neuron → Effector

Answer

Receptor → Motor neuron → Relay neuron → Sensory neuron → Effector

Question 64

Which of the following molecules is responsible for carrying the genetic code during protein synthesis?

Accepted Answer

mRNA

Answer

DNA

Answer

tRNA

Answer

rRNA