U2. Organisation of organisms

Question 1

Name the organisation level of living things

Answer 1

Organelle, cell, tissue, organ, organ system, organism

Question 2

Define organelle

Answer 2

a structure in a cell

Question 3

Define cell

Answer 3

A functional basic unit of an organism

Question 4

Define tissue

Answer 4

A group of cells with similar structures, working together to perform a shared function

Question 5

Define organ

Answer 5

A structure made up of a group of tissues, working together to perform specific functions

Question 6

Define organ system

Answer 6

A group of organs with related functions, working together to perform body functions

Question 7

Define organism

Answer 7

All organ systems working together to form a biological entity

Question 8

How are new cells produced?

Answer 8

by division of exsisting cells

Question 9

What are common in all living cells?

Answer 9

• cytoplasm
• cell membrane
• DNA as a genetic material (cytoplasm/enclosed in nucleus)
• enzymes for respiration (release energy)
• ribosomes (making protein)

Question 10

Functions of cytoplasm

Answer 10

Contains enzymes for chemical reactions

• supports cell structures
• site of many chemical reactions
• contains water and many solutes
• e.g respiration
• found in all cells

Question 11

Where is cytoplasm found and what does it contain?

Answer 11

enclosed by cell membrane
contains cell organelles (mitochondria, nucleus)

Question 12

Functions of cell membrane

Answer 12

Controls entry and exit in and out of the cell

- present in all cells

Question 13

Functions of ribosomes

Answer 13

Make proteins from amino acids using the information on mRNA (protein synthesis)

• present in all cells
• only visible under electron microscope

Question 14

Functions of nucleus

Answer 14

Enclose DNA, controls cell activities

- not present in prokaryotes

Question 15

What is the nucleus surrounded by and what does this do?

Answer 15

The large nucleus is surrounded by a nuclear membrane to separate it from the cytoplasm

Question 16

Functions of cell wall

Answer 16

Gives shape to the cell, stops cells from bursting when they are placed in pure water
- present: plants, fungus, prokaryote

Question 17

Functions of mitochondria

Answer 17

Site of aerobic respiration - breaks down nutrient molecules to release energy

• present: animals, plants, fungus
• only visible under electron microscope

Question 18

Functions of vesicle

Answer 18

transports substances from a place to another within the cell

• present: animal, plants
• only visible under electron microscope

Question 19

Functions of chloroplast

Answer 19

Site of photosynthesis - converts light energy to chemical energy

• present: plants, some prokaryotes
• packed with chlorophyll

Question 20

Functions of vacuole/permanent vacuole

Answer 20

Stores water and salts

- present only in plants

Question 21

what are specialised cells?

Answer 21

those which have developed certain characteristics in order to perform particular functions.

Question 22

What are the adaptations of cells controlled by?

Answer 22

These differences are controlled by genes in the nucleus

Question 23

what are examples of specialised cells in animals?

Answer 23

• sperm cell
• egg cell
• ciliated epithelial cell
• nerve cell
• red blood cell

Question 24

Sperm cell: function, found in, adaptations

Answer 24

• fertilise egg cell
• found in testes
• small, has a long tail (provides movement: can swim and find egg cell)
• head contains enzymes that allow it to digest into an egg cell and join with it

Question 25

Egg cell: function, found in, adaptations

Answer 25

• fertilised by sperm cell
• found in ovaries
• large, round
• contains yolk: provide large food store for new cell being formed

Question 26

Ciliated epithelial cell: function, found in, adaptations

Answer 26

• stop lung damage
• air passages in lungs
• have cilia (tiny hairs)
• cilia sweep mucus with trapped dust, bacteria back up the throat to protect the lungs

Question 27

Nerve cell: function, `adaptations

Answer 27

• carry electrical signals and nerve impulses to different parts of the body
• long
• have connections at each end

Question 28

Red blood cell: function, found in, adaptations

Answer 28

• carry oxygen
• blood
• biconcave shape, no nucleus: for more haemoglobin and oxygen
• contains haemoglobin (joins with oxygen)

Question 29

what are examples of specialised cells in plants

Answer 29

• palisade mesophyll cells
• root hair cell
• xylem cell

Question 30

Palisade mesophyll cells: function, found in, adaptations

Answer 30

• photosynthesis
• in a leaf (the top)
• tall, large surface area to absorb sunlight and exchange gases (oxygen, CO2)
• packed with chloroplasts: make glucose

Question 31

Root hair cell: function, found in, adaptations

Answer 31

• absorb water, ions
• roots
• large surface area: absorb water and minerals
• thin cell wall: easier for minerals to pass through

Question 32

Xylem cell: function, found in, adaptations

Answer 32

• transport water
• in stem and leaves
• no cytoplasm and cell wall: pass through easily

Question 33

Equation of magnification

Answer 33

magnification = image size / actual size