Science Biology test 2

Question 1

What are the characteristics of living things?

Answer 1

1. Growth and development
2. Reproduction
3. Response to stimuli
4. Metabolism
5. Homeostasis
6. Cellular organization

Question 2

What are the three main points of the cell theory?

Answer 2

1. All living things are composed of cells
2. Cells are the basic unit of life
3. All cells arise from pre-existing cells

Question 3

What is the difference between unicellular and multicellular organisms? Give examples.

Answer 3

Unicellular: composed of a single cell (e.g., bacteria)
Multicellular: composed of multiple cells (e.g., humans, plants)

Question 4

List the functions and appearances of the following cell organelles: nucleus, cell membrane, cell wall, mitochondria, chloroplasts, vacuoles, ribosomes.

Answer 4

• Nucleus: controls cell activities, contains DNA
• Cell membrane: protects cell, regulates entry/exit
• Cell wall: provides structure, protects (in plants)
• Mitochondria: produces energy (ATP)
• Chloroplasts: conducts photosynthesis (in plants)
• Vacuoles: storage of substances
• Ribosomes: synthesizes proteins

Question 5

What are the differences between plant and animal cells in terms of organelles?

Answer 5

Plant cells have cell walls and chloroplasts; animal cells do not. Both have mitochondria and ribosomes.

Question 6

How do you calculate the total magnification of a light microscope?

Answer 6

Ocular lens magnification x objective lens magnification

Question 7

What is the basic procedure for preparing a specimen for examination under a light microscope?

Answer 7

1. Place the specimen on a slide
2. Add a drop of water or stain
3. Cover with a coverslip
4. Adjust the microscope settings

Question 8

What are the main parts of a microscope?

Answer 8

• Ocular lens
• Objective lens
• Stage
• Illuminator
• Base
• Arm

Question 9

What is a safe handling procedure for a microscope?

Answer 9

Always carry with two hands, keep lenses clean, and do not touch the glass with fingers.

Question 10

What are the levels of organization in biological systems?

Answer 10

Cell → Tissue → Organ → System → Organism

Question 11

What is the difference between physical (mechanical) and chemical digestion? Provide examples.

Answer 11

Physical: breaking food into smaller pieces (e.g., chewing)
Chemical: breaking down food into nutrients (e.g., enzyme action)

Question 12

What is the difference between the digestive system and the digestive tract?

Answer 12

Digestive system: includes all organs involved in digestion
Digestive tract: the pathway food travels through (mouth to anus)

Question 13

List the major organs of the digestive system in order of appearance and their functions.

Answer 13

• Mouth: mechanical and chemical digestion
• Oesophagus: transports food to stomach
• Stomach: further digestion and mixing
• Small intestine: nutrient absorption
• Pancreas: produces digestive enzymes
• Liver: produces bile, processes nutrients
• Large intestine: absorbs water, forms waste
• Rectum and anus: expels waste

Question 14

What is peristalsis and where does it occur?

Answer 14

Peristalsis: wave-like muscle contractions that move food through the digestive tract, occurring in the oesophagus, stomach, and intestines.

Question 15

Label the four chambers of the human heart.

Answer 15

1. Right atrium
2. Right ventricle
3. Left atrium
4. Left ventricle

Question 16

What is the difference between atria and ventricles?

Answer 16

Atria: upper chambers that receive blood
Ventricles: lower chambers that pump blood out of the heart

Question 17

What is the function of valves in the heart?

Answer 17

Prevent backflow of blood and ensure one-way flow through the heart

Question 18

Describe the path of oxygenated and deoxygenated blood through the heart, lungs, and body.

Answer 18

Deoxygenated blood enters right atrium → right ventricle → lungs (oxygenated) → left atrium → left ventricle → body

Question 19

What are the differences between types of blood vessels?

Answer 19

• Arteries: carry oxygenated blood away from the heart
• Veins: carry deoxygenated blood to the heart
• Capillaries: exchange of substances between blood and tissues

Question 20

What is the difference in appearance and function between red blood cells, white blood cells, and platelets?

Answer 20

• Red blood cells: carry oxygen, biconcave shape
• White blood cells: immune response, larger and varied shapes
• Platelets: clotting, small cell fragments

Question 21

What are the variables in a biological experiment?

Answer 21

Independent variable, dependent variable, controlled variables

Question 22

What does it mean to draw a conclusion from data made in an experiment?

Answer 22

To interpret the results and determine if they support or refute the hypothesis