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Flashcards in Topic 1 Deck (59)
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1
Q

What do only plant cells have that human cells don’t

A

Rigid cell wall
Large vacuole
Chloroplast

2
Q

What does the nucleus contain and what does it do

A

DNA that controls what he cell does

3
Q

What is the cytoplasm

A

Gel-like substance where most chemical reactions happen

4
Q

What does the cell membrane do

A

Holds the cell together and controls what goes in and out

5
Q

What is the mitochondria

A

Where most of reactions for respiration to take place, which releases energy needed for cells to work

6
Q

What is the rigid cell wall made of and what does it do

A

Cellulose and gives support oft the cell

7
Q

What does the large vacuole contain

A

Cell sap, weak solution of sugars and salts

8
Q

What is chloroplast

A

Where photosynthesis occurs and contains green chlorophyll

9
Q

What 4 things do both plant and animal cells have

A

Nucleus
Cytoplasm
Cell membrane
Mitochondria

10
Q

Where is Chromosomal DNA found in a bacterial cell and what does it do

A

It is one long circular chromosome that floats in the cytoplasm
Controls cells activities and replication

11
Q

What are plasmids (in bacterial cells)

A

Small loops of extra DNA that aren’t part of the chromosome
Contain genes for things like drug resistance
Can be passed between bacteria

12
Q

What is flagellum (flagella) and what does it do in bacterial cells

A

Long, hairlike structure that rotates making bacteria move

13
Q

What is a bacterial cell supported by

A

Cell wall

14
Q

Name two types of microscopes

A

Light

Electron

15
Q

Structure of DNA

A

Two strands coiled together in the shape of a double helix

16
Q

Adenine and

A

Thymine

17
Q

Guanine and

A

Cytosine

18
Q

DNA Codes for

A

Proteins

19
Q

DNA pairs are joined together by

A

Weak hydrogen bonds

20
Q

What four people are responsible for the discovery of the structure of DNA

A

Franklin and Wilkins

Watson And Crick

21
Q

How did Franklin and Wilkins discover the helical structure of DNA

A

By directing beams of x-rays onto crystallised DNA

Looked at patterns formed as x-rays bounced off

22
Q

What did Watson and Crick do

A

Created a model fitting all together the structure of DNA including the base pairs A-T C-G

23
Q

How do cells make proteins

A

By stringing amino acids together in specific orders

24
Q

What are proteins made by

A

Ribosomes (organelles)

25
Q

Describe the process of translation showing how proteins are made

A

DNA is to big to move out of nucleus which cells need to get the info from to give to ribosome in cell cytoplasm
Does so using MRNA as the messenger (shorter single strand)
DNA strands unzip and used as template to make MRNA, base paring ensuring complementary = TRANSCRIPTION
MRNA molecules move out of nucleus and join ribosome
Amino acids brought to ribosome that match MRNA code by TRNA
Ribsomes stick amino acids together in chain =polypeptide(protein) following order of bases in MRNA =TRANSLATION

26
Q

What is a mutation

A

A change in organisms DNA base sequence that could effect sequence of amino acids in protein
Effecting shape and function there changing characteristics of organism

27
Q

What three things can mutations be

A

Harmful
Beneficial
Neutral

28
Q

Enzymes are

A

Biological catalysts

29
Q

A benefit and negative of enzymes

A

They speed up both useful and non useful reactions by increasing temperature

30
Q

All enzymes are

A

Proteins

Work inside and outside body

31
Q

Examples of how enzymes work in and outside of cells

A

DNA replication
Protein synthesis
Digestion

32
Q

A substrate is

A

A molecule that changes in a reaction

33
Q

For an enzyme to work

A

The substrate must fit into the active site perfectly
However enzymes have high specificity for their substrate
“Lock and key” mechanism

34
Q

Three things effecting enzymes

A

Temperature
PH
Substrate concentration

35
Q

Optimum PH for enzymes

A

PH 7

Except pepsin in stomach works best in acidic conditions PH2

36
Q

What is the human genome project

A

Thousands of scientist collaborating to find every human gene
25,000

37
Q

Positives of they an genome project

A
Medicine and forensic science
Predict and prevent diseases
New and better medicines
Accurate diagnoses
Improve forensic science
38
Q

Negatives oft he human genome project

A

Not being perfect
Increase stress (knowing susceptible to disease for young age)
Gene-ism (pressure not to have children)
Des criminality by employers and insurers

39
Q

Describe the process of Genetic engineering

A

1) useful gene “cut” from chromosome using restriction enzyme
2) enzyme used to cut another chromosome and insert useful gene into another organism (genetically modified organism)

40
Q

Three benefits of genetic engineering for humans

A

Reducing vitamin A deficiency -gold rice beta-carotene
Produce human insulin- insulin gene injected into bacteria
Increase crop yeild- GM resistant to herbicides

41
Q

Long term concerns of Genetic engineering

A

Reduce biodiversity of weeds and flowers(wildlife)
Not convinced are safe
Fear of transplanted genes getting into environment e.g ‘superweeds’

42
Q

Mitosis makes new cells for

A

Growth and repair

43
Q

Mitosis uses

A

Human body cells= diploid

One of each mother no father chromosome

44
Q

Mitosis produces

A

Two identical cells to original

45
Q

Mitosis is used in ……… reproduction

A

Asexual

46
Q

Describe briefly the process of mitosis

A

1) cell not dividing, DNA spreads in long strings
2) cell devices and duplicates DNA, copies form x-shaped chromosomes each arm exact duplicate of other
3) line up in centre and cell fibres bull the apart to opposite sides of cell
4) membranes form around each cell becoming nuclei or 2 new cells
5) cytoplasm divides forming two diploid cells

47
Q

Meiosis uses

A

Gametes
Half usual number of chromosomes
Ova and sperm

48
Q

Meiosis is used in ……… reproduction

A

Sexual

49
Q

Gametes are

A

Haploid

50
Q

When two gametes join together they form the right number of chromosomes which is

A

Zygote- which are diploid and have the right amount of chromosomes

51
Q

Three factors of meiosis

A

1) to make new cell with half number of chromosomes cell divides
2) only in reproductive organs
3) produce 4 haploid nuclei (chromosomes not identical)

52
Q

Describe the processor of the first division in meiosis

A

DIVISION 1

1) cell duplicates DNA each arm exact copy of chromosome
2) chromosome pairs lime up centre of cell
3) cell fibres bull apart each cell one copy of each chromosome (M&F)
4) mixture of alleles creates variation in offspring

53
Q

Describe the process of the second division in meiosis

A

1) chromosomes reline up in centre of cell and pulled apart

2) 4 haploid gametes each with single set of chromosomes in it

54
Q

Name three uses of cloning mammals

A

Storage organs for transplantation
Study lead to greater understanding of embryo, age and age-related illness
Preserve endangered species

55
Q

Three issues with cloning mammals

A

‘Reduce gene pool’ fewer alleles in population
Not live as long eg dolly 8 years 1/2 as long as normal
Risks and problems with health

56
Q

Describe the prices of stem cells

A

Fertilised egg divides by mitosis to produce bundle of cells
Embryonic stem cells are all the same in embryo (undifferentiated)
Divide to produce more stem cells or different types of specialist cells

57
Q

Differentiation is

A

The process of stem cells becoming specialised.

Embryo developes recognisable human body with organs and systems

58
Q

What is the difference between animal and plant stem cells

A

Animals look ability to differentiate at young age (adults only in bone marrow, not a versatile to differentiate as from embryos)
Plants never lose ability

59
Q

Ethical concerns of stem cells

A

Embryos shouldn’t be used-potential life
Aim of curing patients suffering more important than human life?
Banned in some countries (strict guidelines in uk)