1.1 Introduction to cells Flashcards

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1
Q

3 core ideas of cell theory

A
  1. Cell is the smallest structural unit of life
  2. Cells can only arise from pre-existing cells
  3. All living organisms are made of cells
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2
Q

Evidence that organisms are made of cells

A
  • Cells divide and multiply by meiosis or mitosis
  • Cells are divided into little compartments when observed under the microscope
  • Organelles are specialized structures with specific functions and which cannot survive alone
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3
Q

Atypical examples that disprove cell theory + what they disprove

A
  1. Striated muscle cell: Defies that cells should have one nucleus
  2. Aseptate hyphae: Defies that cell should be a single unit. Usually hyphae have multiple septa to divide.
  3. Giant algae: Defies idea that a cell should be simple and small. It could exceed 7cm. It is also complex with long stalks and a cap of long branches
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4
Q

7 functions of life

A

MR H GREN

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5
Q

Functions of life in a paramecium

A
Reproduction: Large nucleus 
Response: Cilia
Nutrition: Food vacuole 
Homeostasis: Contractile vacuole 
Excretion: Cell membrane 
Metabolism: Cytoplasm
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6
Q

Functions of life in chlorella

A
Reproduction: Nucleus 
Nutrition: Chloroplasts 
Metabolism: Cytoplasm 
Homeostasis: Contractile vacuole 
Excretion: Plasma membrane
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7
Q

Importance of SA:V ratio

A
  • If ratio is too small, substances cannot enter cells as quickly and waste products will accumulate
  • Cells may overheat as heat is produced faster than it’s released from surface
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8
Q

How do they maintain SA:V?

A
  • Shorter diffusion pathways
  • Concentration gradients should be easy to generate
  • Folding if membranes to increase SA
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9
Q

Emergent properties and function

A

Properties that arise from interaction between component parts. It allows multicellular organisms to complete functions that could not have been done by individual cells

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10
Q

Advantages of emergent properties

A
  • Efficient as cells carry out fewer roles faster and so they save energy
  • Cells can develop ideal structure for their function to increase efficiency
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11
Q

In which cell is entire genome active?

A

Totipotent

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12
Q

How do newly formed cells become specialized?

A
  • Cells receive signals to deactivate certain genes
  • Deactivated genes are tightly packed into heterochromatin
  • Other genes are expressed, loosely packed into euchromatin
  • Cells become specialized as genes repressed and expressed are different
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13
Q

How many different specialized cell types exist currently?

A

220

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14
Q

What is a stem cell?

A

They are undifferentiated cells that can form more cells of the same type and from which other type of cells can arise from differentiation.

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15
Q

Totipotent

A

Differentiate into any cell type and can give rise to a complete organism eg. Zygote

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16
Q

Pluripotent

A

Can self-replicate and differentiate into many types of cells but cannot give rise to a complete organism eg. Embryonic stem cells from blastocyst

17
Q

Multipotent

A

Can differentiate into few closely related cells but more limited eg. Adult and cord cells

18
Q

Unipotent

A

Can regenerate but only differentiate into cell type it arose from eg. Muscle and skin cells

19
Q

Stargardt’s macular dystrophy

A
  • Recessive genetic condition
  • Mutation causes active transport protein on photoreceptor cells to malfunction and degenerate
  • Causes progressive loss of central vision
20
Q

How does stem cell treatment work for macular dystrophy

A

Stem cells are divided and differentiated to become retinal cells. They are injected into retina where they hopefully attach and restore vision. Currently only viable treatment

21
Q

Leukemia

A
  • Cancer of the blood or bone marrow

- Results in abnormally high amounts of poorly functioning white blood cells

22
Q

How does stem cell treatment work for leukemia?

A
  • Uses hematopoietic stem cells which are harvested from marrow, peripheral blood or cord cells
  • Chemo or radiotherapy can be used but it destroys healthy bone marrow so HSC is injected into bone marrow to form new WBCs.
  • Less rejection of patient’s own HSC compared to marrow transplants
23
Q

Differentiation in embryo, cord blood and adult stem cells

A

Embryo: Differentiate into any type

Cord + Adult: Limited capacity

24
Q

Genetic damage in embryo, cord blood and adult stem cells

A

Embryo + Cord: Less chance of genetic damage

Adult: Due to accumulation of mutations throughout life, genetic damage can occur

25
Q

Compatibility of embryo, cord blood and adult stem cells to parent cells

A

Embryo: Not genetically identical to parent

Cord + Adult: Fully compatible with parent as they are genetically identical

26
Q

Main arguments FOR therapeutic cloning

A
  • May pave the way for future discoveries and beneficial technology
  • Can be used to treat and cure serious diseases and disabilities
  • Transplants are less likely to be rejected
  • They do not require death of another human
  • Cells are taken when embryo doesn’t have nervous system and hence doesn’t feel pain
  • Can be created without need for destruction of natural human embryo
27
Q

Main arguments AGAINST therapeutic cloning

A
  • Embryonic stem cells are capable of continued division and may develop into cancerous cells or tumors
  • More embryos are produced than needed so excess are killed
  • Religious or moral objects due to the ‘Playing God’ argument
  • Embryo could potentially be used in IVF and develop into a human fetus
  • Potential for race to clone first human
28
Q

Equation for magnification

A

Image size / Actual size

29
Q

How to use a scale bar

A

Measure scale bar and then divide by actual size given on scale bar to get magnification

30
Q

Metabolism

A

Sum of all chemical reactions inside cells of an organism, including respiration for energy

31
Q

Response

A

Ability to react to changes in the environment, includes movement and sensitivity

32
Q

Homeostasis

A

Regulation of bodily conditions within tolerable limits

33
Q

Growth

A

Irreversible increase in size

34
Q

Reproduction

A

Producing offspring sexually or asexually

35
Q

Excretion

A

Removal of waste products of metabolism

36
Q

Nutrition

A

Obtaining food to provide energy and materials required for growth

37
Q

Units of measure for cells (largest to smallest)

A

mm- millimeters
um- micrometers
nm- nanometers