introduction to biology

Question 1

what are the Characteristics of living things

Answer 1

There are seven processes that are common to living things:

• movement
• sensitivity
• growth
• reproduction
• excretion
• nutrition
• respiration

Question 2

what are cells

Answer 2

• The cell is the basic unit of life
• Every living thing is made of cells
• Every cell originates from a pre-existing cell
• Cells carry out life processes
• Cells may have specialised functions
• Their anatomy and biochemistry reflects their function
• Cells possess the seven processes central to living things

Question 3

key features about movement

Answer 3

• Living things can control and direct where and when they move
• Plant cells can orientate to light (phototropism)
• Bacterial and sperm cells ‘swim’ using a flagellum
• Skin cells crawl to heal a wound

Question 4

Sensitivity

Answer 4

Ability to detect and respond to changes in the environment around them

Question 5

Reproduction

Answer 5

• Cell can divide to form two identical daughter cells (mitosis)
• Genetic information in the nucleus is duplicated
• Mitosis allows cells of tissues to divide for growth and repair

Question 6

Growth

Answer 6

• Increase in size, maturity and complexity

e.g formation of multicellular organism from single cell

Question 7

Nutrition & Excretion

Answer 7

• Nutrients provide the raw materials for energy to fuel life processes, growth and repair
• The chemical processes essential for life produce toxic/unwanted waste which must be excreted

Question 8

Cellular Respiration

Answer 8

• Production of chemical energy from nutrients to fuel vital life processes
• Cellular respiration differs from physiological respiration

Question 9

facts about cells

Answer 9

• 50-100 trillion in the human body
• 200 major types
• Average cell diameter is 50 micrometers (0.05mm)
• Basic structure can be studied using a light microscope
• Special stains and techniques aid contrast and definition

Question 10

Levels of organisation

Answer 10

• Chemical components (atoms, molecules)
• Cell components (organelles)
• Cells
• Tissues
• Organs
• Organ Systems
• Organism
• Populations

Question 11

Animal Cell Structure

Answer 11

nucleus, cytoplasm,cell membrane

Question 12

whats the function of the nucleus

Answer 12

• The control centre is the nucleus

* Genetic information

Question 13

whats the function of the cytoplasm?

Answer 13

• The cytoplasm is a gel-like mix of biochemicals in which biochemical reactions occur

Question 14

whats the function of the cell membrane ?

Answer 14

• Around the cell is the cell membrane

• Barrier
• Controls movement of materials in and out of the cell

Question 15

unique structures that only plants have?

Answer 15

they have a cell wall, a large vacuole and chloroplasts

Question 16

Plant cells have a rigid cell wall

Answer 16

• Composed of fibres of cellulose

* Outside plasma membrane

Question 17

Plants cells have a large vacuole

Answer 17

• Helps to maintain cell turgor
• Storage/movement of substances
• Some animal cells have vacuoles

Question 18

Plants cells contain chloroplasts

Answer 18

• Small round structures containing chlorophyll
• Green pigment
• Used in photosynthesis

Question 19

Tonoplast

Answer 19

a membrane which bounds the chief vacuole of a plant cell.