1.1 CELL BIOLOGY

Question 1

Cell Theory

Answer 1

The cell is the smallest unit of life

All living things are composed of cells

Cells only arise from pre-existing cells

Question 2

Proves for The cell is the smallest unit of life

Answer 2

Subcellular components have never been seen to perform the functions of life whereas full cells have

Question 3

Proves for All living things are composed of cells

Answer 3

From the 17th century on, biologists examined tissues from both plants and animals and saw that every specimen contained at least one or more cells

Question 4

Proves for Cells only arise from pre-existing cells

Answer 4

We have observed cells coming from other cells, but never observed spontaneous generation

Question 5

Unicellular Organism

Answer 5

organisms consisting of only one cell, it carries out all functions of life in that cell

Question 6

Function of life

Answer 6

Nutrition

Metabolism

Growth

Response

Homeostasis

Reproduction

Excretion

Question 7

Nutrition

Answer 7

Obtaining food. To provide energy and the materials needed for growth

Question 8

Metabolism

Answer 8

Chemical reactions inside the cell, including cell respirations to release energy

Question 9

Growth

Answer 9

An invisible increase in size

Question 10

Response

Answer 10

The ability to react to changes in the environment

Question 11

Homeostasis

Answer 11

Keeping conditions inside the organisms within tolerable limits

Question 12

Reproduction

Answer 12

Production offspring either sexually or asexually

Question 13

Unicellular organism: Paramecium

Answer 13

They are heterotrophs, feeding on food particles they encounter in their environment

Widespread in aquatic environments, particularly in stagnant ponds

Question 14

Paramecium Function of life

Answer 14

M: Reactions in the cytoplasm catalysed by enzymes

Rs: Reacts to stimuli: Reverse direction of movement when it touches a solid object

H: Keeps internal conditions within limits

G: Increases in size and dry mass by accumulating organic matter and minerals from its food

E: Expels waste products of metabolism: CO2 from respiration diffuses out of the cell

Rt: Reproduces asexually or sexually

N: Feeds on smaller organisms by ingesting and digesting them in vesicles

Question 15

Unicellular organism: Chlamydomonas

Answer 15

They are autotrophs; they can manufacture their own food using their large chloroplast to photosynthesise.

Distributed all over the world, in soil, freshwater, oceans, and even in snow on mountaintops

Question 16

Chlamydomonas Functions of life

Answer 16

M: Reactions in the cytoplasm catalysed by enzymes

Rs: Reacts to stimuli: Senses where the brightest light is with its eyespot and swims towards it

H: Keeps internal conditions within limits

G: Increases in size and dry mass due to photosynthesis and absorption of minerals

E: Excepts waste products of metabolism: Oxygen from photosynthesis diffuses out of the cell

Rt: Reproduces asexually or sexually

N: Produces its own food by photosynthesis using a chloroplast that occupies much of the cell

Question 17

Surface area: Volume

Question 18

Multicellular Organisms

Answer 18

Organisms consisting of a single mass of cells, fused together

Question 19

Emergent Properties

Answer 19

a characteristic an entity gains when it becomes part of a bigger system

Question 20

Tissue

Answer 20

a group of cells specialise in the same way to perform the same function

Question 21

Cell Differentiation

Answer 21

the process during development whereby newly formed cells become more specialised and distinct from one another as they mature

Question 22

Gene expression

Answer 22

the process by which the information encoded in a gene is used to direct the synthesis of a functional gene product, which can be a protein, RNA molecule, or non-coding RNA

Question 23

Stem cells

Answer 23

An undifferentiated cell that can:
1. Divide indefinitely to create more stem cells
2. Differentiate to become a specialised cell type in a multicellular organism

Question 24

Non-therapeutic uses of stem cells

Answer 24

Production of large quantities of striated muscle fibres, or meat for human consumption

Ex. beef burgers without the need of killing the animal

Question 25

Therapeutic uses of stem cells

Answer 25

Production of regenerated tissue
Ex. skin for people who suffered burns