Organisation of the Organism

Question 1

What are cells?(3)

Answer 1

Cells are the building blocks of life; all living things are made of cells, and new cells are produced by the division of existing cells.

Question 2

What structures are found in a typical eukaryotic cell?

Answer 2

Cell membrane, cytoplasm, nucleus, mitochondria, ribosomes, and endoplasmic reticulum.

Question 3

What is the function of the cell membrane?

Answer 3

It controls movement in and out of cells.

Question 4

Where do chemical and metabolic reactions occur in a cell?

Answer 4

In the cytoplasm.

Question 5

What is the function of the nucleus?

Answer 5

The nucleus contains DNA, stores genetic information, and controls the activity of the cell.

Question 6

Where does aerobic respiration occur in a cell?

Answer 6

In the mitochondria.

Question 7

What is the function of ribosomes?

Answer 7

They allow protein synthesis in the cytoplasm.

Question 8

What additional structures do plant cells have that animal cells do not?

Answer 8

Vacuole, cell wall, and chloroplasts.

Question 9

What is the function of a plant cell’s vacuole?

Answer 9

It contains cell sap to keep the cell turgid.

Question 10

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

Answer 10

It strengthens the cell and holds its shape.

Question 11

Why are chloroplasts important in plant cells?

Answer 11

They contain chlorophyll, which absorbs light energy for photosynthesis.

Question 12

What is a prokaryote?

Answer 12

A unicellular organism that does not have mitochondria or a true nucleus, such as bacteria.

Question 13

What structures are found in a bacterial cell?

Answer 13

Cell wall (made of peptidoglycan), cell membrane, cytoplasm, ribosomes, plasmids, and a circular chromosome of DNA.

Question 14

What are plasmids?

Answer 14

Small, circular rings of DNA in the cytoplasm that contain extra genes outside the chromosomal DNA.

Question 15

What is the hierarchy of levels of organization in living organisms?

Answer 15

Cells → Tissues → Organs → Organ Systems → Organisms.

Question 16

Define tissue, organ, and organ system.

Answer 16

Tissue: Groups of cells with similar structures working together to perform a shared function.
Organ: Groups of tissues working together to perform a specific function.
Organ system: Groups of organs with related functions working together to perform body functions.

Question 17

What are specialised cells, and name two examples.

Answer 17

Specialised cells have specific functions. Examples include ciliated cells (move mucus) and red blood cells (transport oxygen).

Question 18

What is the formula for magnification?

Answer 18

Magnification = Size of drawing ÷ Size of specimen = Image size ÷ Actual size.

Question 19

How can you calculate actual size and image size in magnification?

Answer 19

Actual size: Image size ÷ MagnificationImage
size: Magnification × Actual size.

Question 20

What are the key unit conversions in magnification?

Answer 20

1 cm = 10 mm
1 mm = 1000 μm
1 μm = 0.001 mm.
Magnification has no units (e.g., ‘×50’ or ‘×5000’).

Question 21

Name one location and function of a root hair cell.

Answer 21

Location: Roots.
Function: Absorption of water and minerals.

Question 22

What is the function of ciliated cells, and where are they found?

Answer 22

Function: Movement of mucus.
Location: Respiratory tract, fallopian tubes.

Question 23

What is the function of palisade mesophyll cells, and where are they found?

Answer 23

Function: Photosynthesis.
Location: Leaf cells.

Question 24

What is the significance of specialised cells like neurones?

Answer 24

Neurones conduct electrical impulses throughout the organism.

Question 25

What are sperm and egg cells specialised for, and where are they found?

Answer 25

Specialised for reproduction, found in their respective gonads.