Topic 2 Flashcards Preview

Edexcel GCSE Biology > Topic 2 > Flashcards

Flashcards in Topic 2 Deck (78)
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1
Q

Adult Stem Cells

A

Stem cells that can differentiate into a limited range of cell types

2
Q

Asexual Reproduction

A

A form of reproduction involving a single parent that creates a genetically identical offspring

3
Q

Axon

A

A long fibre that conducts nerve impulses away from the cell body

4
Q

Cancer

A

A non-communicable disease caused by changes in the cell that lead to uncontrolled growth

5
Q

Cataract

A

A cloudy patch that forms on the lens preventing light from entering the eye

6
Q

Cell Differentiation

A

The process where a cell becomes specialised for its function

7
Q

Cell Elongation

A

The process which cells expand and enlarge enabling the growth of a plant.

8
Q

Central Nervous System

A

The brain and spinal cord

9
Q

Cerebellum

A

The region of the brain the coordinates muscles and non-voluntary movement. (Eg: Balance and Posture)

10
Q

Cerebral Hemisphere

A

One half of the cerebellum, each half controls corresponding half of the body

11
Q

Cerebrum

A

The largest region of the brain made of 2 hemispheres. Responsible for movement, memory, intelligence, language and vision.

12
Q

Chromatid

A

One ‘arm’ of a replicated chromosome

13
Q

Chromosome

A

A long coiled molecule of DNA that carries genetic information in the form of genes

14
Q

Colour Blindness

A

A deficiency of the eye making it difficult to distinguish between colours.

15
Q

Cone Cells

A

Cells found in the retina that are sensitive to high light intensity (bright lights) and detect different colours.

16
Q

Cornea

A

The transparent out layer that reflects light entering the eye.

17
Q

CT Scan

A

A imaging technique that uses X-Rays to make a detailed imagine of internal organs.

18
Q

Dendrites

A

Short, branched extensions of dendrons that provide large surface areas to receive nervous impulses from other neurones

19
Q

Dendron

A

Branched extension of nerve cell body that connects to other neurones and carries impulses towards the body

20
Q

Diploid Cell

A

A cell that contains 2 copies of each chromosome

21
Q

Effector

A

An organ, tissue or cell that produces a response to a stimulus

22
Q

Embryonic Stem Cells

A

Stem cells found very early in embryos that are unspecialised and capable of differentiating into any cell type

23
Q

Eye

A

A sense organ containing receptors sensitive to light intensity and colours

24
Q

Growth

A

An increase in mass or size

25
Q

Haploid Cell

A

A cell that contains a single copy of each chromosome

26
Q

Iris

A

A pigmented ring of muscles that controls the size of the pupil to alter how much light enters the eye

27
Q

Lens

A

A transparent biconvex structure that refracts light focusing it onto the retina.

28
Q

Long-Sightedness

A

A defect of the eye where nearby objects appear out of focus due to convergence of light rays behind the retina. This occurs when the eyeball is too short or the less is less elastic. This is fixed using a convex lens.

29
Q

Medulla Oblongata

A

The region of the brain that controls unconscious activity such as breathing and heart rate

30
Q

Meristem Tissue

A

Plant tissues containing undifferentiated stem cells

31
Q

Motor Neurone

A

A neurone that carries nerve impulses from the CNS to the effectors.

32
Q

Myelin Sheath

A

A electrically insulating layer that surrounds the axon and increases the speed of nerve impulses

33
Q

Neurones

A

Nerve cells adapted to quickly transmit nerve impulses. They are the functional part of the Immune system

34
Q

Neurotransmitters

A

Chemicals that are used for communication between neurones and their target cells

35
Q

Percentile Chart

A

A chart used to monitor growth or time. Can be compared to expected values helping to identify abnormal patterns.

36
Q

PET Scan

A

An imaging technique used to assess the structure and function of the brain through the use of radioactive chemicals. Comparison to a normal brain can highlight unusually active or inactive areas.

37
Q

Pupil

A

A hole in the centre of the iris that allows light to enter the eye

38
Q

Reflex

A

A rapid and automatic response to a stimulus by the body

39
Q

Reflex Arc

A
Stimulus 
Sensory Receptor
Sensory Neurone 
Relay Neurone 
Motor Neurone
Effector 
Response
40
Q

Relay Neurone

A

A neurone that carries nerve impulses from sensory neurones to motor neurones within the CNS.

41
Q

Retina

A

A light sensitive layer at the back of the eye composed of rod and come cells. It converts light into nerve signals sent to the brain

42
Q

Rod Cells

A

Cells found in the retina that are sensitive to low light intensity

43
Q

Sensory Neurone

A

A neurone that carries nerve impulses from receptors to the CNS

44
Q

Sensory receptors

A

A specialised structure that detects a specific type of stimulus

45
Q

Short-Sightedness

A

A defect of the eye where distant object appear out of focus due to the convergence of the light rays in front of the retina. This occurs when the eyeball is too long or the lens is too thick and too rounded. It is corrected using a concave lens

46
Q

Stem cells

A

Cells that are unspecialised and capable of differentiating into a range of cell types

47
Q

Synapse

A

A small gap in between neurones which a nerve impulse is transmitted via neurotransmitters.

48
Q

Nucleus is made of…

A

Genetic information made of chromosomes containing DNA.

49
Q

A Gene

A

A short section of DNA that codes for a protein and controls a characteristic

50
Q

How Many Pairs of Chromosomes are in Each Cell?

A

23 Pairs - 46 Chromosomes

51
Q

Sex Cells Have…

A

Half the number of chromosomes

52
Q

A diploid cell has…

A

46 Chromosomes

53
Q

A Haploid Cell Has…

A

23 Chromosomes

54
Q

Haploid Cell Examples

A

Sperm and Egg Cells

55
Q

Cell Division is for…

A

Growth and development, replacing damaged cells and a vital part of asexual reproduction.

56
Q

Mitosis Produces…

A

2 Identical Diploid Daughter Cells

57
Q

Nucleus contains…

A

Chromosomes

58
Q

Chromosomes Contain…

A

DNA

59
Q

Genes are…

A

A short section of DNA that codes for a protein.

60
Q

Each chromosome carries many…

A

Gene’s

61
Q

Amount of Chromosomes

A

23 Pairs (Half from Father and Half from Mother)

62
Q

Sex Cells are also know as…

A

Gametes

63
Q

Gametes have…

A

23 Chromosomes in Total

64
Q

A diploid is…

A

23 Pairs of Chromosones

65
Q

A Haploid is…

A

23 Chromosomes in Total

66
Q

Cell Cycle…

A

Interphase, Prophase, Metaphase, Anaphase, Telophase, Cytokinesis

67
Q

Interphase

A

Stage 1

DNA copies itself ready for mitosis.

68
Q

Prophase

A

Stage 2

DNA chromosome become more visible and membrane around nucleus disappears.

69
Q

Metaphase

A

Stage 3

Chromosomes and their copies are line up in the middle of the cell.

70
Q

Anaphase

A

Stage 4

Chromosomes and their copies are pulled to different ends of the cells.

71
Q

Telophase

A

Stage 5

New membranes form around the chromosomes at each end of the cell.

72
Q

Cytokinesis

A

The cell membrane pinches in and divides the two daughter cells.

73
Q

Mitosis

A

A form of cell division that produces two genetically identical cells (with full sets of chromosomes) from one parent cell.

74
Q

Cancer is caused by…

A

Small changes in cells that lead to uncontrolled cell division. A group of these cells are called a tumour.

75
Q

If a Child is in the 95th Percentile for Height it is…

A

Taller than 95% of children of the same age and shorter than 5% of children of the same age.

76
Q
A

Form when an egg and sperm cell fuse to form a zygote.
Can differentiate into any cell in the body.
Can be replicated in lab conditions.

77
Q

Adult Stem Cells

A

Found in bone marrow.

Can make many types of cell like red blood cells.

78
Q

Meristems

A

Found in plant roots and shoot tips.
Can differentiate into any type of plant.
Can be used to clones plants.