Chap 1, Cell Structure And Organisation

Question 1

What does the protoplasm of a cell consist of

Answer 1

-cell surface membrane
-cytoplasm
-vacuole
-nucleus

Question 2

Organelles (4)(+1)

Answer 2

-mitochondrion
-nucleus
-ribosome
-vacuole

(Chloroplast)

Question 3

Cell surface membrane

Answer 3

-controls movement of substances in & out of cells
-partially permeable
-made up of lipids & proteins

Question 4

Cell wall

Answer 4

-Made of cellulose
-protects cell from injury & gives the plant cell a fixed shape
-fully permeable

Question 5

Cytoplasm

Answer 5

-Contains organelles
-where most cell activities occur

Question 6

What is an organelle?

Answer 6

A membrane bound structure that performs a specific job within a cell.
-many are not visible under the light microscope. Only can be studied under an electron microscope (mitochondria & ribosomes)

Question 7

Nucleus

Answer 7

-surrounded by nucleus membrane
-contains genetic information in the form of chromosomes (DNA)
-controls cell activities such as cell growth & repair of worn out cells
-essential for cell division

Question 8

Vacuoles

Answer 8

-fluid filled space
-stores substances within the cell
plant cells have a large central vacuole; contains cell sap -> contains dissolves food substances like sugars, mineral salts & amino acids
animal cells have many temporary small vacuoles; contains water & food substances

Question 9

Mitochondria (singular; mitochondrion)

Answer 9

-small oval shaped organelle; bound by a membrane
-breaks down glucose in the presence of oxygen; to release energy for cell activities; aerobic respiration

Question 10

Ribosomes

Answer 10

-small round structure
-attached to organelles within the cell or lie freely in the cytoplasm
-are needed to synthesise proteins in the cell

Question 11

Chloroplast

Answer 11

-Oval structures found in plant cells
-contains green pigment called chloroplast

Question 12

Difference between animal and plant cells?

Answer 12

-Plant cells have a large central vacuole while animal cells have many temporary small vacuoles
-plant cells have cell wall while animal cell does not
-plant cells contain chloroplast while animal cell does not

Question 13

Describe the structure of red blood cell and how it transports oxygen around the body.

Answer 13

-contains haemoglobin which binds oxygen and transports it around the body
-has a circular, biconcave shape which increases surface area to volume ratio so oxygen can diffuse in and out at a higher rate
-lacks a nucleus, enabling the cell to store more haemoglobin for the transport of oxygen
-is flexible and can squeeze through capillaries easily

Question 14

Muscle cell

Answer 14

-is elongated and cylindrical in shape
-contains many nuclei & mitochondria
-has mitochondria to release the energy for the contraction & relaxation of the muscle cell

Question 15

Describe the structure of root hair cells and how it aids in absorption.

Answer 15

-has a long & narrow root hair to increase the surface area to volume ratio to absorb water & mineral salts at a higher rate
-maintains a lower water potential in vacuole (osmosis)