(P1) Topic 2: Cells And Control

Question 1

What are the stages of mitosis in plants

Answer 1

Prophase
Metaphase
Anaphase
Telophase

Question 2

What are the stages of mitosis in animals

Answer 2

Prophase
Metaphase
Anaphase
Telophase
Cytokinesis

Question 3

What occurs in interphase

Answer 3

The cell grows, replicates its chromosomes, and prepares for cell division

Question 4

What occurs in prophase

Answer 4

Condensing

Question 5

What occurs in metaphase

Answer 5

Chromosomes line up, nucleus dissolves

Question 6

What occurs in anaphase

Answer 6

Chromatids move towards the poles of the cell

Question 7

What occurs in telophase

Answer 7

Chromosomes are at the poles, two nuclei form

Question 8

What occurs in cytokinesis

Answer 8

The cell splits

Question 9

Why does mitosis need to occur

Answer 9

Cells need to divide for growth and repair

Question 10

What are the products mitosis

Answer 10

Two genetically identical daughter cells

Question 11

What does fertilisation create

Answer 11

A zygote

Question 12

Where to totipotent stem cells come from

Answer 12

Zygote

Question 13

Where to multipotent stem cells come from

Answer 13

Embryo

Question 14

Where to pluripotent stem cells come from

Answer 14

Adults

Question 15

How many versions of each chromosome does each cell have

Answer 15

Two, one from each parent

Question 16

Explain how mitosis works (steps + explanation)

Answer 16

1. To prepare for cell division, each chromosome is copied (prophase)
2. The chromosomes line up in the middle of the cell (metaphase)
3. The chromosomes are pulled apart (anaphase)
4. The cells separate (telophase)

Question 17

Issues people have with embryonic stem cells

Answer 17

Christian view- it’s seen as taking a life
Ethical + economic issues

Question 18

What are stem cells

Answer 18

Undifferentiated cells that can be differentiated into other cells

Question 19

Where are stem cells found in plants

Answer 19

In the meristem

Question 20

What type of neurones make up the brain

Answer 20

Relay neurones

Question 21

What is a nerve cell

Answer 21

A collection of neurones

Question 22

What is the optic nerve made of

Answer 22

Sensory neurones

Question 23

Why does the brain have no sense of touch or pain

Answer 23

There are no sensory neurones

Question 24

What are brains mainly made of

Answer 24

Fat

Question 25

What is the term that means the brain can mend

Answer 25

Neuroplasticity

Question 26

What is controlled by the cerebral cortex

Answer 26

Thinking- memories, emotions, conscious decisions, personality

Question 27

What is controlled by the cerebellum

Answer 27

Sensory component- sight, smell, taste

Question 28

What so controlled by the medulla oblongata

Answer 28

Autonomic functions- breathing, blinking, heart beating

Question 29

What is the synapse

Answer 29

Functional gap between two neurones

Question 30

Simple reflex arc

Answer 30

stimulus -> receptor -> sensory neurone -> relay neurone (CNS) -> motor neurone -> effector -> response

Question 31

Where in the body are photoreceptors located

Answer 31

In the eye

Question 32

What do photoreceptors function as

Answer 32

Transducers in converting the external energy of light stimuli into the code of the nervous impulse

Question 33

What does a photoreceptor do

Answer 33

Detect light

Question 34

What is a transducer

Answer 34

Something that can turn energy into another type of energy

Question 35

What part of the mammalian eye are the photoreceptors

Answer 35

The rods and cones

Question 36

What are the rods for

Answer 36

Detecting light level

Question 37

What are the cones for

Answer 37

Detecting colour

Question 38

What part of the eye is responsible for controlling the amount of light entering the eye and how does it do this

Answer 38

The muscles of the iris, by adjusting the size of the pupil accordingly

Question 39

What does the cornea do

Answer 39

Protects the pupil

Question 40

What does the pupil do

Answer 40

Lets in light

Question 41

What does the iris do

Answer 41

Controls the size of the pupil

Question 42

What is the sclera and what does it do

Answer 42

It is the white part of the eye that controls the amount of light in by reflecting light. This prevents over-exposure

Question 43

What is formed when light rays from all points on an object within field of view are focused onto the retina

Answer 43

An inverted image

Question 44

Where are the rods and cones located

Answer 44

In the retina

Question 45

What is the name for a light particle

Answer 45

A photon

Question 46

Do rod and cones cells contain mitochondria

Answer 46

Yes- to have energy to convert energy into different forms

Question 47

What is released in rods when it is dark

Answer 47

Neurotransmitters

Question 48

Characteristics of cones (3)

Answer 48

-discrimination of colour -good visual activity (resolution) -poor sensitivity

Question 49

Characteristics of rods (3)

Answer 49

-Monochromatic vision -poor visual activity (resolution) -good sensitivity

Question 50

What is the theory of trichromatic colour vision

Answer 50

Three varsities of colour-sensitive pigment located in separate cone cells in the retina- different colours and shades are perceived by the degree of stimulation of each type of cone

Question 51

Approximately how many cones are located in the retina

Answer 51

6 million