Paper 1: Section 2- Cells and Control Flashcards

1
Q

What are the differences between mitosis and meiosis?

A

Mitosis: Meiosis:
. Growth and . Gametes
repair
. Asexual . Reproduction
. 2 daughter cells . 4 daughter cells
. Diploid (46) . Haploid (23)
. Identical/ clones . Varied

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2
Q

What are the 6 stages of mitosis?

A

Interphase- DNA is copied
Prophase- the chromosomes pair up and the nucleus dissolves
Metaphase- chromosomes line up in the middle
Anaphase- spindle fibers pull chromosomes to the opposite sides
Telophase- a membrane forms around each set of chromosomes (2 separate nuclei)
Cytokinesis- two separate daughter cells form

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3
Q

What makes the stage of metaphase different in meiosis?

A

Dependant assortment

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4
Q

What is dependant assortment?

A

For any given pair lined in the center of the cell, there is one maternal chromosome and one paternal chromosome.

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5
Q

What is known as crossing over?

A

Segments of each chromosome, in a pair, attach themselves to the other.

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6
Q

What is the result of changes in the cell that lead to uncontrolled cell division?

A

Cancer

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7
Q

What happens to an unspecialised cell when it differentiates?

A

It becomes a specialised cell.

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8
Q

What is a tumour?

A

The lump of cells formed as a result of uncontrolled cell division.

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9
Q

A _______ tumour is not cancerous and cannot ______ to other areas of the body.

A
  1. benign
  2. spread
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10
Q

__________ tumours are fast-growing. They are _________ and can invade and spread to other areas of the ____.

A
  1. Malignant
  2. cancerous
  3. body
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11
Q

Describe the process called metastasis.

A

As the malignant tumour grows, cancer cells detach and can form secondary tumours in other parts of the body.

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12
Q

What are the chemicals and other agents that can cause cancer called?

A

Carcinogens

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13
Q

How do carcinogens cause cancer?

A

By damaging DNA, causing mutations to occur.

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14
Q

What is a mutation?

A

A random and spontaneous change in the structure of a gene, chromosome or number of chromosomes.

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15
Q

What is a common misconception about the growth of cancer?

A

A single mutation will not cause cancer. Several are required for this to occur.

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16
Q

List 5 lifestyle factors that are linked to cancer:

A

. Viruses like HPV
. The chemical carcinogens in cigarette smoke
. Alcohol intake
. Exposure to UV radiation, part of which is ionising,
. Fat and salt intake increases the risk of cancer

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17
Q

List 2 industrial and environmental factors that are linked to cancer:

A

. Exposure to ionising radiation increases the risk factor
. Exposure to chemical carcinogens

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18
Q

Name 7 specialised systems in animals.

A
  1. Circulatory system
  2. Excretory system
  3. Muscular system
  4. Nervous system
  5. Respiratory system
  6. Skeletal system
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19
Q

Name 5 specialised cells in plants.

A
  1. Palisade mesophyll
  2. Spongy mesophyll
  3. Guard cells
  4. Phloem Sieve tubes
  5. Xylem vessels
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20
Q

What is a zygote?

A

A fertilised egg cell.

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21
Q

What happens to an unspecialised cell when it differentiates?

A

It becomes a specialised cell.

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22
Q

What are the 3 following ways growth of babies are measured in?

A
  1. Mass (kg)
  2. Length (cm)
  3. Head circumference (cm)
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23
Q

What is a percentile growth chart?

A

A chart that is used to compare the growth of a baby to the growth of other babies.

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24
Q

What is an adult stem cell?

A

A type of stem cell found in specific locations in adults that can only differentiate into a limited number of related cell types.

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25
Q

What is an embryonic stem cell?

A

A type of stem cell found in the embryo, capable of dividing into almost any cell type.

26
Q

Finish the sentence: Bone marrow cells, being adult stem cells, can differentiate into…

A

blood cells and cells of the immune system, but not other cell types.

27
Q

The main meristems are close to the tip of the ____, and the tip of the ____. Cells of the meristem can ____________ to produce all types of plant cells at any time during the life of the plant.

A
  1. shoot
  2. root
  3. differentiate
28
Q

Name 3 instances where stem cells could be used to replace cells that have been damaged or destroyed:

A

. With type 1 diabetes
. In cases of multiple sclerosis
. In cases of spinal cord or brain injury

29
Q

What are the benefits of using stem cells?

A

Stem cells have the potential to treat a wide range of diseases and injuries. They can be used to replace damaged cells, regenerate tissues, and even cure certain medical conditions.

30
Q

Name 3 medical conditions stem cells can be used to treat.

A

. Diabetes
. Parkinson’s disease
. Heart disease

31
Q

What are 3 risks associated with stem cell therapy?

A

. There is a risk of rejection by the body’s immune system
. A risk of the stem cells turning into cancer cells
. The long-term effects of stem cell therapy are still unknown, so further research is needed.

32
Q

What is the brain and its function?

A

Its part of the CNS,controlling complex behaviour.

33
Q

What is the function of the cerebellum?

A

It controls movement such as balance, coordination, muscles and movement.

34
Q

What is the function of the medulla oblongata?

A

Involved in unconscious control like heart rate, breathing, and producing adrenaline.

35
Q

What is the function of the pituitary gland?

A

Produces important hormones like FSH and LH.

36
Q

What is the function of the hypothalamus?

A

Involved in homeostasis, maintaing body temperature.

37
Q

What is the function of the cerebral cortex?

A

Responsible for the higher-level processes of the human brain. This includes language, memory, thought, decision-making and emotion.

38
Q

What is known as mapping the brain?

A

When research is done in the brain the aim is to ‘map’ the region of the brain to particular functions.

39
Q

Name 4 facts on MRI scans:

A

. Magnetic fields/ EM waves
. Investigates activity + structure of the brain
. Safer than CT scans
. Shows lost ctive during various activities also

40
Q

Name 4 facts on CT scans:

A

. X rays (ionising radiation)
. Investigates structure of the brain by producing images
. They can show damage

41
Q

Name 4 facts on PET scans:

A

. Radioactive chemicals
. Highlights activity of the brain
. Help identify unusual activity

42
Q

Name 4 facts on Electrical stimulation scans:

A

. Used to map areas of the brain
. Certain parts of the brain are stimulated nd the effect is observed
. EEGs are studies to observe this electrical activity

43
Q

Why do we analyse brain damage?

A

. To understand the importance of specific parts of the brain
. Brain scans correlation with body functions

44
Q

What are the risks of brain research?

A

. The tissues of the brain, spinal cord and other parts are intricate and delicate
. Certain damages may be hard to remove
. Brain surgery is dangerous
. Damaged neurones are hard to repair

45
Q

Why can brain treatment be seen as unethical?

A

You may get informed (knowing it’s risk) consent from the individuals.

46
Q

What is the nervous system?

A

The system that helps humans react to their surroundings and coordinate their behaviour.

47
Q

CNS structure: What is the stimulus?

A

A change in environment.

48
Q

CNS structure: What is the receptor?

A

Cell at start of the pathway, that detects the stimuli.

49
Q

CNS structure: What is the coordinator?

A

The CNS coordinates a response.

50
Q

CNS structure: What is the effector?

A

Effect the response (a muscle or a gland).

51
Q

CNS structure: What is the response?

A

The outcome.

52
Q

What does a neurone do?

A

Carry electrical impulses.

53
Q

What are nerves made up off?

A

Neurones/ nerve cells

54
Q

What are the 5 properties of neurones?

A

. Axons
. Myelin sheath
. Cell body
. Dendrons
. Synapses

55
Q

What does a sensory neuron do?

A

Send messages from the receptor to the coordinator.

56
Q

What does a motor neuron do?

A

Sends messages from coordinator to the effector.

57
Q

What does a relay neuron do?

A

Connects the sensory and motor neuron.

58
Q

What is a synapse?

A

A junction between two neurons or a neuron and an effector cell.

59
Q

What is the tiny gap between the cells at a synapse?

A

Synaptic cleft

60
Q

What is a synaptic knob?

A

The presynaptic neuron ends that are swollen, which contain small vesicles neurotransmitters.

61
Q

Neurotransmitters are ______________ messengers that transmit nerve impulses across the ________ gap during the process of synaptic ____________.

A
  1. electrochemical
  2. synaptic
  3. transmission