Unit 1. science biology

Question 1

What is the function of the nucleus?

Answer 1

The nucleus controls the cell’s activities and contains genetic material (DNA).

Question 2

What is the powerhouse of the cell?

Answer 2

The mitochondria, which produce energy (ATP) through cellular respiration.

Question 3

Where does photosynthesis occur in plant cells?

Answer 3

Photosynthesis occurs in the chloroplasts.

Question 4

What does magnification mean in microscopy?

Answer 4

Magnification refers to how much larger an object appears compared to its actual size.

Question 5

What part of the microscope controls the amount of light passing through the specimen?

Answer 5

The diaphragm or iris.

Question 6

What is the basic unit of heredity?

Answer 6

A gene.

Question 7

How many chromosomes are in a human cell?

Answer 7

46 chromosomes (23 pairs).

Question 8

What are the four nitrogenous bases in DNA?

Answer 8

Adenine (A), Thymine (T), Cytosine (C), and Guanine (G).

Question 9

What is the purpose of mitosis?

Answer 9

Mitosis creates two identical daughter cells for growth, repair, or reproduction.

Question 10

What is the difference between osmosis and diffusion?

Answer 10

Osmosis is the movement of water across a membrane, while diffusion is the movement of particles from high to low concentration.

Question 11

In what stage of mitosis do the chromosomes align in the center of the cell?

Answer 11

Metaphase.

Question 12

What happens during interphase in the cell cycle?

Answer 12

The cell grows, replicates its DNA, and prepares for mitosis.

Question 13

What is cancer?

Answer 13

Cancer is the result of uncontrolled cell division caused by mutations in the DNA that bypass cell cycle checkpoints.

Question 14

What is the role of xylem in plants?

Answer 14

Xylem transports water and nutrients from the roots to the rest of the plant.

Question 15

What organelle is unique to plant cells and aids in photosynthesis?

Answer 15

Chloroplasts.

Question 16

What is a stem cell?

Answer 16

A stem cell is an unspecialized cell that can develop into different types of specialized cells.

Question 17

What type of tissue is responsible for covering body surfaces?

Answer 17

Epithelial tissue.

Question 18

What is the main function of the digestive system?

Answer 18

To break down food into nutrients that the body can absorb and use.

Question 19

Which organ is responsible for pumping blood throughout the body?

Answer 19

The heart.

Question 20

What is the primary function of the respiratory system?

Answer 20

To exchange oxygen and carbon dioxide between the body and the environment.

Question 21

How does exercise benefit the circulatory system?

Answer 21

Exercise strengthens the heart, improves circulation, and reduces the risk of cardiovascular disease.

Question 22

What is the main role of the phospholipid bilayer?

Answer 22

To control what enters and exits the cell.

Question 23

How do mitochondria and chloroplasts differ in their energy roles?

Answer 23

Mitochondria make ATP from glucose; chloroplasts make glucose from sunlight.

Question 24

What is the function of lysosomes?

Answer 24

They digest waste and broken cell parts.

Question 25

Why are both magnification and resolution important in microscopy?

Answer 25

Magnification enlarges; resolution shows detail.

Question 26

Why do scientists stain cells before viewing under a microscope?

Answer 26

To make cell structures easier to see.

Question 27

What are chromosomes made of?

Answer 27

DNA tightly coiled around proteins.

Question 28

What is the role of DNA in cells?

Answer 28

It stores genetic information.

Question 29

How do genes relate to proteins?

Answer 29

Genes provide instructions to make proteins.

Question 30

What happens during anaphase in mitosis?

Answer 30

Sister chromatids are pulled apart.

Question 31

What is the main difference between osmosis and diffusion?

Answer 31

Osmosis is water movement; diffusion is particle movement.

Question 32

Why is mitosis important for multicellular organisms?

Answer 32

It allows growth and cell repair.

Question 33

What happens at the G1 checkpoint?

Answer 33

The cell checks for DNA damage and readiness for DNA replication.

Question 34

How does cancer develop in relation to the cell cycle?

Answer 34

Cancer develops when cell cycle checkpoints fail, leading to uncontrolled division.

Question 35

What phase of the cell cycle is the longest?

Answer 35

Interphase.

Question 36

What is the function of the xylem in plants?

Answer 36

It transports water from roots to leaves.

Question 37

How do plant cells differ from animal cells?

Answer 37

Plant cells have cell walls, chloroplasts, and large vacuoles.

Question 38

What is the main role of the stomata in leaves?

Answer 38

Gas exchange.

Question 39

What is the difference between embryonic and adult stem cells?

Answer 39

Embryonic cells can become any type; adult cells are more limited.

Question 40

What is the function of connective tissue in animals?

Answer 40

To support and connect different parts of the body.

Question 41

How does nervous tissue function in the body?

Answer 41

It transmits electrical signals for communication.

Question 42

What is the primary function of the small intestine?

Answer 42

Nutrient absorption.

Question 43

What does the circulatory system transport?

Answer 43

Blood, oxygen, and nutrients.

Question 44

How do the lungs function in the respiratory system?

Answer 44

They exchange oxygen and carbon dioxide.

Question 45

How does exercise improve cardiovascular health?

Answer 45

It strengthens the heart and improves circulation.

Question 46

How does proper hydration affect the body's systems?

Answer 46

It helps organs function and maintains blood volume.