Cell Biology Topic 1 Flashcards

1
Q

What are eukaryotic cells?

A

Animal and plant cells.
They have a cell membrane, cytoplasm,and nucleus containing DNA

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2
Q

What are prokaryotic cells?

A

Bacterial cells
They have a cell wall, cell membrane, cytoplasm, single circular strand of DNA and plasmids (small rings of DNA found in the cytoplasm and no membrane bound organelle

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3
Q

What are the units of measurement?

A

Prefix: Multiply unit by:
Centi 0.01
Milli 0.001
Micro 0.000,001
Nano 0.000,000,001

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4
Q

Function of the nucleus

A

Contains DNA coding for a particular protein needed to build new cells

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5
Q

Cytoplasm

A

Liquid substance in which chemical reactions occur
Contains enzymes (biological catalysts i.e. proteins that speed up the rate of reaction

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6
Q

Cell membrane

A

Controls what enters and leaves the cell

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7
Q

Mitochondria

A

Where aerobic respiration reactions occur, providing energy for the cell

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8
Q

Ribosomes

A

Where protein synthesis occurs

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9
Q

Chloroplasts

A

Where photosynthesis takes place, providing food for the plant
Contains chlorophyll pigment which harvests the light needed for photosynthesis

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10
Q

Vacuole

A

Contains cell sap
Found within cytoplasm
Improves cell’s rigidity

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11
Q

Cell wall

A

Made from cellulose
Provides strength to the cell

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12
Q

What are plasmids

A

Small rings of DNA

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13
Q

how are sperm cells specialised

A

streamlined head and long tail to aid in swimming, many mitochondria which supply energy to allow the cell, top id the head has digestive enzymes which breakdown the outer layers of the egg cells membrane

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14
Q

how are nerve cells specialised

A

the axon is long which allows the impulses to b carried along long distances, dendrites mean that branched connections can form with other nerve cells

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15
Q

how are muscle cells specialised

A

lots of mitochondria to provide energy from respiration for contraction, can store a chemical change called glycogen that is used in respiration by mitochondria, special proteins that slide over each other causing the muscle to contract

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16
Q

how are root hair cells specialised

A

large surface area due to root hairs meaning more water can move in via osmosis, large permanent vacuole affects speed of movement of water from soil to the cell, mitochondria to provide energy from respiration for the active transport of mineral ions into the root hair cell

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17
Q

how are xylem cells specialised

A

when forming, a chemical called lignin is deposited which causes the cells to die and the cell becomes hollow and are joined end to end to form a continuous tube so that water and mineral ions can move through. lignin is also deposited in spirals which helps the cells withstand the pressure of movement of water

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18
Q

how are phloem cells specialised

A

cell walls of each cell form structures called sieve plates when the break down allowing movement of substances from cell to cell

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19
Q

what must stem cells undergo to become specialised

A

differentiation

20
Q

how do cells differentiate in animals

A

almost all differentiate at an early stage then lose the ability. moat specialised cells make more by mitosis bit others such as red blood cells are replaced by adult stem cells

21
Q

how do cells differentiate in plants

A

man types have the ability of differentiation throughout life and only differentiate when when they reach their final position in the plant but can still re-differentiate when moved to another position

22
Q

equation for magnification of a light microscope

A

magnification of eyepiece lens x magnification of the objective lens

23
Q

equation for size of an object

A

image/magnification

24
Q

where is genetic info contained

A

nucleus

25
Q

what do chromosomes contain

A

coils of DNA

26
Q

what is a gene

A

a short section of DNA

27
Q

how many pairs of chromosomes are in each cell

A

23 pairs- 46 single

28
Q

how many total chromosomes are in a gamete

A

23

29
Q

describe stage 1 (interphase) of the cell cycle

A

growth- organelles grow and increase in number and protein synthesis occurs and DNA is replicated

30
Q

describe stage 2 (mitosis) of the cell cycle

A

one set of chromosomes is pulled to each end of the cell and the nucleus divides into 2

31
Q

describe stage 3 (cytokinesis) of the cell cycle

A

two identical daughter cells form when the cytoplasm and cell membranes divide

32
Q

what is a stem cell

A

an undifferentiated cell which can undergo division to produce many more similar cells of which some will differentiate to have different functions

33
Q

how are embryonic stem cells formed

A

when an egg and sperm cell fuse to form a zygote

34
Q

what type of cells can embryonic stem cells differentiate to

A

any

35
Q

what can scientists do with embryonic stem cells

A

clone them and direct them to differentiate into almost any cell in the body

36
Q

where are adult stem cells that can form many different types of cells, including blood cells, be found

A

bone marrow

37
Q

where are meristems found

A

root and shoot tips

38
Q

why may cloning a plant be neccessary

A

for reasearch or to save a plant from extinction

39
Q

what is theraputic cloning

A

an embryo being produced with the same genes as the patient which can then be harvested to obtain the embryonic stem cells

40
Q

what is one advantage of theraputic cloning

A

they wont be rejected as they have the exact same genetic make up as the individual

41
Q

what are 5 problems of research with stem cells

A
  1. we dont fully understand the process of differentiation- hard to control stem cells and where the cells form
  2. removal of stem cells may result in destruction of embryo
  3. religious or ethical objections
  4. stem cells may be contaminated
  5. money and time could be better spoent in other area of medicine
42
Q

what are 3 benefits of research with stem cells

A
  1. can be used to replace damaged or diseased body parts
  2. unwanted embryos would not be used otherwise
  3. reaserch into the process of differentiation
43
Q

what is the definition of diffusion?

A

the spreading out of particles of any substance in solution, or particles of gas resulting in a net movement from an area of high concentration to lower concentration

44
Q

is diffusion passive (requires no energy)

A

yes

45
Q

name one example of diffusion in the body

A

(gas exchange) oxygen moves through the membranes of alveoli in the lungs into the red blood cells and is carried across the body for respitation. carbon dioxide (the waste product of respiration)moves from the red blood cells into the lungs to be exhaled

46
Q
A