SB2 - Cells and Control

Question 1

adult stem cells

Answer 1

A stem cell found in specialised tissue that can produce more of the specialised cells in that tissue for growth and repair.

Question 2

asexual reproduction

Answer 2

Producing new organisms from one parent only. These organisms are genetically identical to the parent.

Question 3

cancer

Answer 3

A disease caused by the uncontrolled divison of stem cells in a part of the body

Question 4

cataract

Answer 4

Build up of protein in the lens of the eye.

Question 5

cell cycle

Answer 5

A sequence of growth and division that happens in cells. It includes interphase and mitosis, and leads to the production of two daughter cells that are identical to the parent cells.

Question 6

central nervous system (CNS)

Answer 6

The main part of the nervous system that includes the brain and the spinal cord.

Question 7

cerebellum

Question 8

cerebral cortex

Answer 8

The main part of the brain, which is used for most of our senses, language, memory, behavior and conciousness.

Question 9

cerebral hemispheres

Answer 9

The cerebral cortex is divided into two cerebral hemispheres.

Question 10

chemotherapy

Answer 10

Use of drugs that treat a disease, such as in treatment of cancer.

Question 11

colour-blind

q

Answer 11

An eye defect in which someone cannot see the full range of colours.

Question 12

cones

Answer 12

A cell in the retina that detects different colours of light.

Question 13

constrict

Answer 13

To make narrower

Question 14

CT scan

Answer 14

A scan in which multiple X-rays are taken of the body and put together by a computer. CT stands for computed tomography.

Question 15

daughter cells

Answer 15

A new cell produced from the division of a parent cell.

Question 16

dilate

Answer 16

To make wider.

Question 17

diploid

Answer 17

A cell or nucleus that has two sets of chromosomes. In humans, almost all cells except the sperm and egg cells are diploid.

Question 18

DNA replication

Answer 18

Where DNA molecules are copied before cell division occurs.

Question 19

effectors

Answer 19

A muscle or gland in the body that performs an action when an impulse from the nervous system is recieved.

Question 20

elongation

Answer 20

When something gets longer such as a cell in a plant root or shoot before it differentiates into a specialised cell.

Question 21

embryonic stem cells

Answer 21

A cell from an early stage of division of an embryo that can produce almost any kind of differentaiated cell.

Question 22

gamma rays

Answer 22

A high-frequencey electromagnetic wave emitted from the nucleus of a radioactive atom.

Question 23

haploid

Answer 23

A cell or nucleus that has one set of chromosomes. Gametes are haploid.

Question 24

impulses

Answer 24

An electrical signal transmitted along a neurone.

Question 25

interphase

Answer 25

The stage during which a cell prepares itself for cell division.

Question 26

iris

Answer 26

The coloured part of the eye. Muscles in it control the diameter of the pupil.

Question 27

long-sighted

Answer 27

An eye condition where close objects appear blurred.

Question 28

meristem cells

Answer 28

A stem cell found in a plant meristem

Question 29

meristems

Answer 29

A small area of undiffererentiated cells in a plant where cells are dividing rapidly by mitosis.

Question 30

mitosis

Answer 30

The process of dividing to produce two diploid daughter cells that are genetically identical to the parent.

Question 31

motor neurones

Answer 31

A type of neurone that carries impulses to effectors

Question 32

nerves

Answer 32

A cell that transmits electrical impulses in the nervous system.

Question 33

neurones

Answer 33

A cell that transmits electrical impulses in the nervous system.

Question 34

optic nerve

Answer 34

The nerve that transmits impulses from the retina to the brain.

Question 35

percentile

Answer 35

The value of a variable below which a certain percentage of observations fall.

Question 36

pupil

Answer 36

The hole in the front of the eye that light can pass through.

Question 37

quadriplegia

Answer 37

A condition in which both arms and legs are paralysed.

Question 38

radioactive

Answer 38

A substance is radioactive if it emits ionisng particles or radiation.

Question 39

radiotherapy

Answer 39

Use of ionising radiation to treat diseases, such as to kill cancer cells.

Question 40

receptor cells

Answer 40

A cell that recieves a stimulus and converts it into ane electrical impulse to be sent to the brain and/or spinal cord.

Question 41

reflex

Question 42

relay neurones

Answer 42

A short type of neurone found in the spinal cord and brain. Relay neurones link with sensory, motor and other relay neurones.

Question 43

rods

Answer 43

A cell in the retina that detects low levels of light. It cannot detect colours.

Question 44

root hair cells

Answer 44

A cell found on the surface of plant roots that has a large surface area to absorb water and dissolved mineral salts quickly from the soil.

Question 45

sense organs

Answer 45

An organ that contains receptor cells.

Question 46

retina

Answer 46

The part at the back of the eye that changes energy transfeered by light into nerve impulses. Contains rods and cones.

Question 47

short-sighted

Answer 47

An eye condition where distant objects seem blurred.

Question 48

spinal cord

Answer 48

The large bundle of nervers leading from the brain and down the back.

Question 49

stem cells

Answer 49

An unspecialised cell that continues to divide by mitosis to produce more stem cells and other cells that differentiate into specialised cells.

Question 50

stimulus

Answer 50

A change in factor that is detected by receptors.

Question 51

synapse

Answer 51

The point at which two neurones meet. There is a tiny gap between neurones at a synapse.

Question 52

tumours

Answer 52

A lump formed of cancer cells.

Question 53

xylem cells

Answer 53

A long, thick-walled tube found in plants, formed from many dead xylem cells.