Reproduction And Inheritance Flashcards

1
Q

Define Diploid Cells:

A
  • Two copies of each chromosome arranged in pairs

* Diploid number of human cell nucleus is 46 chromosomes

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2
Q

Define Haploid Cells:

A

•Single chromosome in a cell (23)

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3
Q

Describe the structure of DNA:

A
  • Double helix structure of two strands made up of sugar phosphate backbone
  • Held together by bases which are paired
  • Adenine pairs with Thymine and Cytosine pairs with Guanine
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4
Q

What is the function of tRNA in translation?

A
  • Transports amino acids in ribosome

* Has anticodon which is complementary to codon on mRNA

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5
Q

What is a codon?

A
  • Each amino acid is coded for by a sequence of three bases in the gene
  • E.g. ACA or CTG
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6
Q

How are Proteins made?

A
  • Made up of chains of amino acids
  • Each protein has a different number and order of amino acids
  • Each protein can have a different function
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7
Q

Define a gene:

A
  • A section of DNA that codes for a particular protein

* Each gene contains different sequence of bases

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8
Q

Define Chromosomes:

A

Long strings of DNA

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9
Q

What is Protein Synthesis?

A
  • Nucleus contains chromosomes
  • DNA in nucleus is too big to leave nucleus
  • Polymerase separates DNA into 2 strands
  • Transcription makes a mRNA of the DNA strand
  • mRNA has swapped the base of thymine with uracil
  • mRNA is now small enough to leave the nucleus
  • mRNA floats out to the cytoplasm, joins with an organelle called ribosome
  • Amino Acids to ribosome by tRNA
  • Translation is reading mRNA, creating corresponding protein via tRNA
  • Amino Acids joined together - amino acid chain so now a protein
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10
Q

Define Mitosis:

A
  • A cell reproduces itself by splitting to form two cells with identical sets of chromosomes
  • Asexual reproduction
  • Produces genetically identical cells
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11
Q

Define Asexual reproduction:

A
  • Involves one parent

* Offspring have identical genes to parent

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12
Q

What is the function of Mitosis?

A
  • Grow and repair damaged cells

* Asexual reproduction

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13
Q

Define Sexual Reproduction:

A
  • Fusion of male and female gametes

* Two parent cells, offspring contain mixture of their parent genes

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14
Q

Define Meiosis:

A
  • Type of Cell division
  • Produces 4 haploid cells
  • Chromosomes not identical
  • Only happens in reproductive organs (ovaries and testes)
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15
Q

What are causes of variation?

A
  • Mitosis In sexual reproduction

* Environmental effects

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16
Q

How many genes control the majority of characteristics?

A

2

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17
Q

What are differences between Mitosis and Meiosis?

A
  • Cell division in Meiosis but only 1 in Mitosis
  • Mitosis takes place throughout body, Meiosis only occurs in reproductive organs (ovaries and testes)
  • Mitosis creates daughter cells with identical DNA
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18
Q

Define Pollination:

A

Transfer of pollen from an anther to a stigma so male gametes can fertilise the female gametes in sexual reproduction

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19
Q

Define Cross Pollination:

A
  • Type of sexual reproduction where pollen is transferred from the anther of one plant to stigma of another
  • Plants rely on insects or wind to help cross pollinate
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20
Q

How are Plants adapted for Insect Pollination?

A
  • Large bright petals - attract insects
  • Scented flowers and nectaries - attract insects
  • Enclosed stamen
  • Sticky stigma - pollen will stick to it
  • Big sticky pollen grains - grain stick to insect as going from plant to plant
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21
Q

How are Plants adapted for Wind Pollination?

A
  • Small dull petals
  • No nectaries or strong scent
  • Many small and light pollen grains - easily carried by wind
  • Stamen exposes
  • Large feathery stigma - catch pollen from wind
  • Long filament that hangs out of flower - a lot of pollen gets blown away by wind
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22
Q

Describe the Stamen (Male Reproductive Part) of the flower:

A
  • Stamen is anther & filament
  • Anther contains pollen grains - produce male gametes (sperm)
  • Filament is the stalk that supports anther
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23
Q

Describe the Carpel (Female Reproductive Part) of the flower:

A
  • Carpel is ovary, style & stigma
  • Stigma is end but that pollen grains attach to
  • Style is rod-like section that supports stigma
  • Ovary contains female gametes (egg) inside ovules
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24
Q

How is a seed formed?

A
  • Pollen lands on stigma
  • Pollen tube grows to ovary
  • Nucleus travels into ovule
  • Nucleus fertilises ovum
  • Fertilisation is two nuclei fusing together to make a zygote
  • Divide by Mitosis to form embryo
  • Seed is formed
  • Fruit is formed
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25
Q

What are the conditions for germination to occur?

A
  • Moisture- Solution for enzymes to function
  • Oxygen - Respiration
  • Warmth - Speed up chemical reactions
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26
Q

How can you investigate the conditions needed for germination?

A
  • Take 4 boiling tubes with Cotten wool at bottom with seeds on top
  • Tube 1 - H2O, O2, room temp
  • Tube 2 - O2, room temp
  • Tube 3 - H20, O2, low temp
  • Tube 4 - H20, room temp
  • Leave for few days & observe
  • Germination only in Tube 1 - all conditions were present
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27
Q

How do Plants reproduce asexually using the natural method of Runners?

A
  • Plant sends out runners - fast growing stems that grow out sideways, above ground
  • Runners take root at various points and new plants grow
  • New Plants are clones of parent plant
  • No genetic variation between them
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28
Q

How do Plants reproduce asexually using the artificial method of Cuttings?

A
  • Take cuttings from good parent Plants, plant them to produce genetically identical copies (clones) of parent plant
  • Cuttings kept in moist conditions
  • Plants can be produced quickly and cheaply
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29
Q

What is the function of Testes?

A

Produce sperm

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30
Q

What is the function of Prostate Gland?

A

Release fluid to form semen

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31
Q

What is the function of Urethra?

A

Transport semen out of the body

32
Q

What is the function of the Penis?

A

Sexual intercourse

33
Q

What is the function of the Sperm Duct (Vas Deferens)?

A

Carries sperm from testes towards urethra

34
Q

What is the function of the Uterus?

A
  • Embryo grows

* Foetus develops

35
Q

What is the function of the Vagina?

A

Sexual intercourse

36
Q

What is the function of the Ovary?

A
  • Produce sex Hormones

* Produce eggs

37
Q

What is the function of the Oviduct?

A
  • Fertilisation takes place

* Carries ovum from ovary to uterus

38
Q

What does Oestrogen in women cause?

A
  • Hair underarms and pubic area
  • Hips to widen
  • Development of breasts
  • Ovum release and start of periods
39
Q

What does Testosterone in men cause?

A
  • Hair on face and body
  • Muscles to develop
  • Penis and testicles to enlarge
  • Sperm production
  • Deepening is voice
40
Q

Describe the Menstrual Cycle:

A
  • Day 1 = Menstruation starts, uterus lining breaks down
  • Day 4-14 = Uterus lining builds up into think spongy layer ready to receive a fertilised egg
  • Day 14 = Egg develops and is released from ovary - ovulation
  • Day 14-28 = The wall is maintained, if no egg landed on uterus wall, spongy lining break down and cycle starts again
41
Q

What Hormones is the Menstrual Cycle controlled by?

A
  • FSH
  • Oestrogen
  • LH
  • Progrsterone
42
Q

What is the hormone FSH?

A
  • Produced In Pituitary Gland
  • Causes egg to mature in a follicle structure
  • Stimulates ovaries to produce Oestrogen
  • Oestrogen inhibits the release of FSH
43
Q

What is the hormone Oestrogen?

A
  • Produced In Ovaries
  • Causes uterus lining to grow
  • Stimulates release of LH
44
Q

What is the hormone LH?

A
  • Produced In Pituitary Gland

* Stimulates release of egg at day 14 - ovulation

45
Q

What is the hormone Progesterone?

A
  • Produced In Ovaries by remains of follicle after ovulation
  • Maintains uterus lining of 2nd half of cycle
  • When levels of progesterone fall, lining breaks down
  • Inhibits release of LH and FSH
46
Q

What is an Allele?

A

Different versions of the same gene

47
Q

What is a Genotype?

A

The alleles that you have

48
Q

What is a Phenotype?

A

The characteristics the alleles produce

49
Q

What are the Dominant Alleles show by?

A

A capital letter

50
Q

What are the Recessive Alleles show by?

A

A small letter

51
Q

What does it mean if you are Homozygous?

A
  • For a trait you have 2 alleles the same for that particular gene
  • E.g. CC or cc
52
Q

What does it mean if you are Heterozygous?

A
  • For a trait you have 2 different alleles for that particular gene
  • E.g. Cc
53
Q

What is meant by Codominant?

A

2 alleles are equally expressed

54
Q

What is the probability of having a daughter if you already had two sons? Explain your answer:

A
  • 50%

* Male has equal chance of producing X (female) or Y (male) in Chromosomes in gamete

55
Q

A black mouse is bred with a brown mouse. All offspring have black fur. Which allele is dominant?

A

Black

56
Q

What letters represents the Male Chromosomes?

A

XY

57
Q

What letters represent the Female Chromosomes?

A

XX

58
Q

How is the baby protected from bumps and shocks?

A

Amniotic Fluid

59
Q

Which factors aren’t affected by environment and are only genetic?

A
  • Eye colour
  • Hair colour
  • Inherited disordered
  • Blood group
60
Q

How does a mother’s diet affect the baby?

A

•Affect baby’s weight

61
Q

How is Health affected by genes and environment?

A
  • Some people more likely to get certain diseases cause in their genes (cancer,etc)
  • However, if you smoke or only eat junk food it can lead to diseases too
62
Q

How is Intelligence affected by genes and environment?

A
  • Maximum IQ determined by genes

* Also, determined by school life and upbringing

63
Q

How is Sporting Ability affected by genes and environment?

A
  • Genes determines your potential

* Also, training is important

64
Q

What are Plants affected by in the Environment?

A
  • Sunlight
  • Moisture level
  • Temperature
  • Mineral content of soil
65
Q

What is the Theory Of Evolution?

A

Life began as simple organisms from which more complex organisms evolved

66
Q

What is Polygenes?

A
  • Most characteristics are coded for by more than 1 gene

* Height, intelligence, body type

67
Q

What was Darwin’s Theory of Evolution?

A
  • Presence of natural variation (in population of organisms)
  • Competition for limited resources
  • Survival of the fittest
  • Inheritance of successful adaptions
  • Extinction of species unable to compete
68
Q

What is an example of natural selection to do with bacteria?

A

Over time, bacteria can become resistant to certain antibiotics

69
Q

What is Transgenics?

A

Foreign DNA, including DNA from humans, can be inserted into animals

70
Q

What are Mutations?

A
  • Changes to a genetic code
  • Rare
  • Change sequence of DNA base, produces genetic variant, sometimes changes the protein that it codes for
71
Q

What could a Mutation in gene that Codes for an Enzyme lead to?

A
  • Change in shape of an enzymes active site

* Altering it’s function

72
Q

What do Most Mutations have no effect on?

A
  • Recessive allele

* Phenotype - they’re neutral

73
Q

What does Mutations have an effect on very rarely?

A
  • Significant effect on phenotype
  • Result in different protein that can no longer carry out its function
  • Harmful - cancer
74
Q

How is a chance of Mutation Increased?

A
  • Ionising radiation = X-rays, gamma rays, UV rays

* Chemicals - Mutagens = chemicals in tobacco

75
Q

What does is mean if Bacteria is Antibiotic Resistance?

A
  • In large population of bacteria, some aren’t affected by antibiotic - due to mutation
  • They survive and reproduce, creating more bacteria that are not affected by antibiotic