diversity in animal cells 2.6 Flashcards

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1
Q

what is differentiation

A

the process by which stem cells become specialised into different types of cells

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2
Q

what do multicellular organisms start life as

A

as a single undifferentiated cell, called a zygote

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3
Q

whats the genome

A

all the genetic material in an individual

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4
Q

how do cells differentiate

A

by turning off certain genes and turning others on

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5
Q

specialised animal cell: what do erythrocytes do

A

carry oxygen from the lungs to respiring cells

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6
Q

specialised animal cell: what do neutrophils do

A

ingest invading pathogens

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7
Q

how are erythrocytes adapted

A
  • large sa to vol ratio
  • flexible, a well developed cytoskeleton allows them to change shape
  • no nucleus, mitochondria or ER so more haemoglobin molecules within them
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8
Q

what are spermatozoa and how are they specialised

A
  • sperm cell
  • many mitochondria for aerobic respiration
  • ATP provides energy for the tail
  • long and thin
  • once it reaches the ovum, the enzymes are released at the acrosome (specialised lysosome)
  • head of sperm contains haploid male gamete
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9
Q

what are epithelial cells and how are they specialised

A
  • lining tissue
  • makes up wall of alveoli and capillaries
  • lines intestines
  • squamous epithelial cells= flattened in shape
  • cilia can be present
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10
Q

what are palisade cells and how are they specialised

A
  • within leaves
  • pack together closely but co2 can still diffuse in
  • large vacuole so chloroplasts at periphery so co2 can diffuse efficiently
  • contain many chloroplasts
  • contain cytoskeleton threads and motor proteins for movement of chloroplasts
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11
Q

what are guard cells and how are they specialised

A
  • a pair
    -dont carry out photosynthesis
    >light energy is used to produce ATP
    > the ATP actively transports potassium ions lowering water potential
    >water now enters guard cells via osmosis
    > guard cells swell and the stomata (opening) enlarges
    >air enters and gas exchange occurs CO2 diffuses in
    >O2 produced leaves the cell through open stomata
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12
Q

what are root hair cells and how are they specialised

A
  • epidermal cells on the outer layer on young plant roots
  • high sa for absorption of water and mineral ions- hair like projection
  • mineral ions are actively transported into the cell (lowers water potential causing osmosis to occur)
  • have special carrier proteins for active transport
  • root hair cell also produces ATP
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13
Q

what do xylem and phloem form

A
  • form the vascular tissue of plants
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14
Q

whats a tissue

A

a group of simmilar cells working together to form a specific function

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15
Q

what are the 4 tissue types in the body

A
  • epithelial or lining tissue
  • connective tissues
  • muscle tissue
  • nervous tissue
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16
Q

what do connective tissues do

A

hold structures together and provide support e.g blood, bone and cartilage

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17
Q

what does muscle tissue do

A

made of cells that are specialised to contract and cause movement

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18
Q

what does nervous tissue do

A

made of cells specialised to conduct electrical impulses

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19
Q

state things about epithelial tissue (animal)

A
  • lines surfaces
  • cells are close and form continuous sheets
  • no blood vessels- receive nutrients from diffusion
  • cilia may be present
  • for protection, absorption, filtration, excretion and secretion
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20
Q

state things about connective tissue

A
  • widely distributed in the body
  • contains proteins (collagen and elastin) and polysaccharides.
  • consists of an extracellular matrix- enables it to withstand forces (e.g weight)
    examples: blood, bone, cartilage and skin
21
Q

state things about muscle tissue

A
  • many blood vessels present
  • are fibres
  • elongated and contain special organelles called myofilaments allowing muscle tissue to contract
22
Q

talk about cartilage (as a whole)

A

-immature cells in cartilage are called chondroblasts ( can divide in mitosis and secret the extracellular matrix)
-once matrix= synthesised, chondroblasts become mature and less active so are now chondrocytes, which maintain the matrix.
there are 3 types of cartilage= hyaline, fibrous and elastic

23
Q

talk about cartilage: hyaline

A
  • forms the embryonic skeleton
  • C- shaped rings keep the trachea open
  • found in nose, trachea and on the ends of long bones
  • connects ribs to sternum
24
Q

talk about cartilage: fibrous

A

-occurs in discs between vertebrae and in the backbone and in the knee joint

25
Q

talk about cartilage: elastic

A

-makes up outer ear and the epiglottis

26
Q

what are the 3 main types of tissue in plants

A
  • epidermal tissue
  • vascular tissue
  • meristematic tissue
27
Q

talk about epidermal tissue (plants)

A
  • equivalent to epithelial tissue in animals
  • consists of flattered cells the lack chloroplasts ( apart from guard cells)
  • form a protective covering over leaves, stems and roots
  • form waxy cuticle (reduces water loss)
28
Q

talk about vascular tissue

A
  • xylem and phloem
    > xylem vessels carry water and minerals from roots to all parts of the plant
    > phloem sieve tubes transfer the products of photosynthesis, in solution from leaves to par of plants that dont photosynthesise, such as roots, flowers and growing shoots
29
Q

talk about meristematic tissue

A
  • contains stem cells
  • found at the roots and shoot tips and in cambium of vascular bundles
  • the cells in meristems have thin walls with little cellulose, no chloroplasts, not a large vacuole and can divide by mitosis and differentiate into other types of cells.
30
Q

where do new cells arise in plant cells and by what means? how does this occur

A

at the meristems via mitosis

31
Q

what cells can differentiate into xylem vessels or phloem sieve tubes or companion cells? how does this occur

A

cambium cells

32
Q

how do cambium cells differentiate into xylem vessels

A

-lignin is deposited to waterproof them, the ends of the cell breaks down so the xylem forms continuous columns with wide lumens to carry water and dissolved minerals

33
Q

how do cambium cells differentiate into phloem sieve tubes or companion cells

A
  • sieve tubes lose most of their organelles and sieve plated develop between them
  • companion cells retain their organelles and continue metabolic functions to provide ATP for active loading of sugars into the sieve tubes
34
Q

plant organs: what is the function of the leaf

A

-photosynthesis

35
Q

plant organs: what is the function of the root

A
  • anchorage in soil
  • absorption of mineral ions and water
  • storage
36
Q

plant organs: what is the function of the stem

A
  • support
  • holds leaves up so they are exposed to more sunlight
  • transportation of water and minerals
  • transportation of products of photosynthesis
  • storage of products of photosynthesis
37
Q

plant organs: what is the function of the flower

A

-sexual reproduction

38
Q

whats and organ

A

a collection of tissues working together to carry out the same function

39
Q

whats and organ system

A

a number of organs working together to carry out an overall life function

40
Q

what are stem cells

A
  • undifferentiated cells capable of becoming any type of cell
  • described as pluripotent
  • able to express all their genes
  • can divide by mitosis to provide more cells that can then differentiate into specialised cells for growth and tissue repair.
41
Q

what are the 4 sources of stem cells

A
  • embryonic stem cells
  • umbilical cord blood
  • adult stem cells- (found in developed tissues, such as blood, brain, adipose tissue and skin)
  • induced pluripotent stem cells (iPS) developed in labs by reprogramming differentiated cells to switch on certain key genes and become undifferentiated
42
Q

what can stem cells from bone marrow treat

A

sickle cell anaemia and leukaemia and treating the immune system.
-used to restore the patient blood system

43
Q

what are the potential uses of stem cells

A

-bone marrow transplants
-drug research
-developmental biology (how organisms grow and develop)
-repair of damaged tissues or lost tissues
treating neurological diseases( Alzheimer’s and Parkinson’s disease)

44
Q

what is regenerative medicine

A

the fact that stem cells can be used to populate a bioscafflod of an organ and then directed to develop and grow into specific organs for transplanting

45
Q

what are the 4 types of stem cells (pluripotent etc..)

A

-totipotent- can develop into any cell type including placenta and embryo
-pluripotent- can develop into any type of stem cell apart from embryo or placenta
-multipotent- can develop into a few different types of cell
unipotent- can develop into one type of cell

46
Q

function of squamous tissue and location in human body

A
  • Acts as surface/ short diffusion pathway

- Alveoli/ cheek lining/blood vessels

47
Q

function of cilliated tissue and location in human body

A
  • Move/ secrete mucus

- Bronchioles/ bronchi/ trachea/ airways

48
Q

3 types of muscle tissue

A
  • skeletal (cause bones to move)
  • cardiac ( pump blood)
  • smooth (propels substances)