Organization of the organism

Question 1

What are the defining features of eukaryotic cells?

Answer 1

Eukaryotic cells have a nucleus and membrane-bound organelles (e.g. mitochondria, endoplasmic reticulum, Golgi apparatus).

Question 2

What cell structures are common to both animal and plant cells?

Answer 2

Cell membrane

Cytoplasm

Nucleus

Mitochondria

Ribosomes

Question 3

What is the function of the cell membrane?

Answer 3

The cell membrane controls what enters and leaves the cell. It is selectively permeable, allowing some substances to pass through while blocking others.

Question 4

What is the function of the nucleus in a cell?

Answer 4

The nucleus carries the genetic material (DNA) and controls the activities of the cell.

Question 5

What is cytoplasm and what is its function?

Answer 5

Cytoplasm is a jelly-like substance where all chemical reactions in the cell take place.

Question 6

What is the function of ribosomes in a cell?

Answer 6

Ribosomes are the site of protein synthesis.

Question 7

What is the function of the mitochondria?

Answer 7

Mitochondria are the site of aerobic respiration where cells produce energy (ATP) by using oxygen to break down glucose.

Question 8

Why do cells with high metabolism need more mitochondria?

Answer 8

Cells with high metabolism require more mitochondria to produce more energy (ATP) to meet their energy demands.

Question 9

What are the unique structures found in plant cells?

Answer 9

Cell wall

Chloroplasts

Central Permanent vacuole

Question 10

What is the function of the cell wall in plant cells?

Answer 10

The cell wall provides structural support and protection. It also helps maintain the cell’s shape.

Question 11

What is the role of chloroplasts in plant cells?

Answer 11

Chloroplasts contain chlorophyll and are the site of photosynthesis, converting light energy into chemical energy.

Question 12

What is the function of the permanent vacuole in plant cells?

Answer 12

The permanent vacuole contains cell sap, which helps maintain turgor pressure, stores nutrients, and isolates waste products.

Question 13

Do animal cells have vacuoles? If so, how are they different from those in plant cells?

Answer 13

Some animal cells can have vacuoles, but they are not central and are temporary compared to plant cells, where the vacuole is large, central, and permanent.

Question 14

What are the main structures found in bacterial cells?

Answer 14

Cell wall

Cell membrane

Cytoplasm

Ribosomes

Circular DNA

Plasmids

Nucleoid (genetic material)

Plasmids (small DNA molecules)

Question 15

What is the function of the nucleoid in bacterial cells?

Answer 15

The nucleoid is an area in bacterial cells that contains the genetic material (DNA), not enclosed in a membrane like in eukaryotic cells.

Question 16

What are plasmids in bacterial cells?

Answer 16

Plasmids are small, circular DNA molecules found in bacterial cells. They carry additional genes, often related to antibiotic resistance.

Question 17

Do bacterial cells have a nucleus?

Answer 17

No, bacterial cells lack a nucleus. Instead, their genetic material is found in the nucleoid region.

Question 18

What is the function of flagella in bacterial cells?

Answer 18

Flagella help bacterial cells move around by rotating like a propeller, allowing them to swim through liquids (e.g., water or mucus).

Question 19

What are specialized cells?

Answer 19

Specialized cells are cells that have a specific structure and function to perform a particular task more efficiently. They are found in multicellular organisms.

Question 20

What is the function of ciliated cells?

Answer 20

Ciliated cells have hair-like structures (cilia) that move mucus in the trachea and bronchi. This helps trap and remove dust, pathogens, and debris from the respiratory system.

Question 21

What is the function of neurons (nerve cells)?

Answer 21

Neurons are specialized cells that conduct electrical impulses throughout the body. They transmit signals between the brain, spinal cord, and other parts of the body.

Question 22

How are neurons adapted for their function?

Answer 22

Long axon to carry impulses over long distances

Branched dendrites to connect with other neurons

Insulating myelin sheath for faster impulse transmission

Question 23

What is the function of the axon in a neuron?

Answer 23

The axon is a long extension of the neuron that carries nerve impulses away from the cell body toward other cells.

Question 24

What is the fatty sheath around the axon, and what is its function?

Answer 24

The myelin sheath is a fatty layer that insulates the axon and speeds up the transmission of nerve impulses.

Question 25

What is the function of root hair cells?

Answer 25

Root hair cells absorb water and minerals from the soil.

Question 26

How are root hair cells adapted for absorption?

Answer 26

Long extensions (root hairs) increase surface area for absorption Thin cell walls to allow easy water and mineral entry No chloroplasts, as they are underground and do not photosynthesize

Question 27

How are red blood cells adapted to their function?

Answer 27

Red blood cells are adapted by: Biconcave shape to increase surface area for oxygen exchange. No nucleus to maximize space for hemoglobin. Flexible membrane to fit through narrow capillaries.

Question 28

What is the function of red blood cells?

Answer 28

Red blood cells transport oxygen from the lungs to the rest of the body using hemoglobin, which binds to oxygen molecules.

Question 29

How are red blood cells adapted to transport oxygen?

Answer 29

Biconcave shape increases surface area for oxygen exchange Flexible membrane allows them to pass through narrow capillaries No nucleus to provide more space for hemoglobin Contain hemoglobin that binds with oxygen

Question 30

What is the role of hemoglobin in red blood cells?

Answer 30

Hemoglobin is a protein in red blood cells that binds to oxygen in the lungs and releases it in tissues that need it.

Question 31

What is the function of a sperm cell?

Answer 31

The sperm cell is specialized to fertilize the egg cell by delivering male genetic material.

Question 32

How is the sperm cell adapted for its function?

Answer 32

Long tail (flagellum) which allows the cell to swim Streamlined shape to swim efficiently Many mitochondria to provide energy for movement Acrosome contains enzymes to break into the egg Haploid nucleus carries half the genetic information

Question 33

What is the function of an egg cell (ovum)?

Answer 33

The egg cell is specialized to be fertilized by a sperm cell and support the development of the embryo.

Question 34

How is the egg cell adapted for its function?

Answer 34

Large cytoplasm with nutrients to support early development Jelly coat to protect the egg and help sperm binding Haploid nucleus with half the genetic information Cell membrane changes after fertilization to prevent multiple sperm from entering

Question 35

What are the levels of organization in a multicellular organism?

Answer 35

Cell → Tissue → Organ → Organ System

Question 36

What is the hierarchical organization of living organisms from cell to organ system?

Answer 36

Cell: The basic structural and functional unit of all living organisms. Tissue: A group of cells with similar structure and function, working together to perform a specific task. Organ: Made up of different types of tissues working together to perform a specific function. Organ System: A group of organs with related functions working together to perform a major function in the body.

Question 37

Why do cells in the body need to divide?

Answer 37

To allow for growth and repair of tissues.

Question 38

How are new cells produced in the body?

Answer 38

New cells are produced through the division of existing cells.