Multicellular Organisms

Question 1

Events of mitosis

Answer 1

Chromosomes make identical copy of themselves - the two copies are chromatids and stay connected as pairs until later in the process
Chromatid pairs line up at the equator of the cell
Spindle fibres pull the pairs of chromatids apart so only 1 copy of each chromosome moves to each pole of the cell
A nuclear membrane forms around each set of chromosomes at the poles
After the two nuclei have formed, the cytoplasm divides and 2 separate diploid cells are formed

Question 2

Chromatid

Question 3

Equator

Question 4

Spindle fibres

Question 5

What does mitosis do

Answer 5

Mitosis provides new cells for the growth and repair of damaged cells and maintains the diploid chromosome complement

Question 6

Diploid cells have

Answer 6

two matching sets of chromosomes, which are replicated during mitosis

Question 7

Stem cells in animals are

Answer 7

unspecialised cells that can divide in order to self-renew

Question 8

stem cells can become

Answer 8

different types of cells

Question 9

stem cells are involved in

Answer 9

growth and repair

Question 10

stem cells can be obtained

Answer 10

from the embryo at a very early stage

Question 11

Tissue stem cells can be found

Answer 11

in the body throughout life

Question 12

Specialisation of cells leads

Answer 12

to the formation of a variety of cells, tissues, and organs

Question 13

Multicellular organisms have

Answer 13

more than one cell type and are made up of tissues and organs

Question 14

Organs perform

Answer 14

different functions

Question 15

Groups of organs that work together form

Answer 15

systems

Question 15

The cells in organs are

Answer 15

specialised for their function

Question 16

The hierarchy is

Answer 16

cells - tissues - organs - systems
—–>

Question 17

A stimulus is

Answer 17

information that an organism can detect and respond to

Question 18

A response to a stimulus can be

Answer 18

a rapid action from a muscle or a slower response from a gland

Question 19

The nervous system consists of

Answer 19

central nervous system (CNS) and other nerves

Question 20

CNS consists of

Answer 20

brain and spinal cord

Question 21

An animals response to a stimulus is

Answer 21

coordinated by its CNS

Question 22

Cerebrum

Answer 22

is the large folded area of the brain and is responsible for conscious thoughts, reasoning, memory and emotions

Question 23

Cerebellum

Answer 23

is found at the rear of the brain below the cerebrum and controls balance and coordinated movement

Question 24

Medulla

Answer 24

is found at the top of the spinal cord and contains groups of neurons that transmit electrical impulses to the heart and lungs to control heart rate and breathing

Question 25

Electrical impulses

Answer 25

carry messages along neurons

Question 26

Chemicals

Answer 26

transfer these messages between neurons, at synapses

Question 27

Synapse

Answer 27

tiny space occurs between the axon ending of one neuron and the sensory fibre of the next

Question 28

Neurons are of

Answer 28

three types: sensory, inter and motor

Question 30

Sensory neurons

Answer 30

pass information from receptors, which detect changes in environmental factors like light, sound and temp to the CNS

Question 31

Inter neurons

Answer 31

transmit nerve impulses from sensory neurons to motor neurons

Question 32

Motor neurons

Answer 32

transmit impulses from inter neuron to an effector. this enables a response to occur which can be a rapid action from a muscle or a slower response from a gland

Question 33

Receptors

Answer 33

detect sensory input/stimuli

Question 34

Receptors are

Answer 34

groups of specialised cells. they can detect changes in the environment, which are called stimuli, and turn them into electrical impulses.

Question 35

Receptors are located

Answer 35

in the sense organs, such as the ear, eye and skin. each organ has receptors sensitive to particular kinds of stimulus