Science 9 - Biology Unit Test Flashcards

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0
Q

infertility

A

inability of couple to have baby; might be because…

  • male not producing enough sperm
  • male producing deformed/defective sperm
  • female unable to release eggs (not enough of right kind of hormones)
  • medical procedures (chemotherapy or radiation therapy)
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1
Q

cri-du-chat syndrome

A

also known as crying cat syndrome

  • 1 in 50 000 individuals
  • caused by deletion on short arm of chromosome 5
  • usually small at birth
  • respiratory problems
  • larynx (voice box) doesn’t develop correctly (causes cat-like cry)
  • small head, small chin
  • unusually round face, widely set eyes
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2
Q

fetal development

A
  • three layers of gastrula form tissue & organs of a baby
  • takes 38 weeks & divided into three trimesters (three months long)
  • at end of 8 weeks, embryo called fetus
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3
Q

blastula

A
  • end of second week
  • embryo 1.5mm in diameter and has hollow ball of cells
  • cells now embryonic stem cells
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4
Q

Turner syndrome

A
  • 1 in 5000 females
  • only 1 ‘x’ chromosome instead of 2
  • female sexual characteristics underdeveloped
  • short stature
  • swelling of hands and feet
  • low hairline, low-set ears
  • reproductive sterility, absence of menstrual period
  • increased weight –> obesity
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5
Q

homologous chromosomes

A

a pair of matching chromosomes (one from each parent)

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6
Q

when do chromosome mutations occur?

A

during meiosis

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7
Q

when is oocyte cryopreservation used?

A
  • women diagnosed with cancer who have not begun chemotherapy or radiation therapy
  • women undergoing assisted reproductive technologies who do not consider embryo-freezing an option
  • women who want to preserve future ability to have children, because they do not yet have a partner, or for other personal or medical reasons
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8
Q

mating

A

process by which both gametes (sex cells) arrive at the same place at the same time

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9
Q

haploid number

A

(n)
one set
pair of chromosomes

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10
Q

what do karyotypes show?

A

when whole chromosome mutations have occurred

- can be analyzed to diagnose and treat patients with genetic disorders or syndromes

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11
Q

result of whole chromosome mutations in meiosis 1 & 2

A

1 gamete will have 2 copies of 1 chromosome, and another will have none

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12
Q

ectoderm

A
  • outer layer

- cells form skin and nervous system

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13
Q

embryonic development

A
  • early development of organisms

- takes place in humans during first 2 months (8 weeks) after fertilization

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14
Q

impact reproductive technologies in society

A
  • IVF causes higher chance of birth defect
  • most unused embryos donated to stem cell research
  • with AI, most children never know who biological father is
  • in surrogacy, sometimes arguments over custody of child
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15
Q

hormone therapy

A

might cause female to ovulate

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16
Q

third trimester

A

continued growth

- rapid weigh gain; growth and accumulation of fat (26-38 weeks) {40-50 weeks}

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17
Q

three layers of cells that organize during gastrula

A
  • ectoderm
  • mesoderm
  • endoderm
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18
Q

which has a greater impact; chromosome or gene mutations

A

chromosomes mutations because bigger DNA sequences are changed

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19
Q

independent assortment (during meiosis 1)

A
  • homologous pairs of chromosomes separate at equator, move towards opposite poles of the cell
  • many different possibilities for how they will separate produces variation –> there are over 8 million sperm combinations possible for the 23 pairs in an egg or sperm cell!
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20
Q

females (gamete formation)

A

meiosis 1 - produces 2 egg cells (cytoplasm & organelles are not equally divided)
meiosis 2 - produces 4 cells —> three smallest disintegrate –> one large haploid egg cell

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21
Q

result of meiosis? (gametes)

A

four haploid cells, each with half the number of chromosomes

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22
Q

advantages of external fertilization

A
  • little energy required
  • large number offspring produced at once
  • offspring far from parents (less competition and genetic variation maintained)
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23
Q

crossing over during meiosis 1

A
  • parts of non-sister chromatids “cross over” each other and exchange segments of DNA
  • this produces genetic variation
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24
Q

gene mutation

A

change in specific order of A, G, C, and T bases that make up a particular gene

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25
Q

difference between meiosis 1 and 2?

A

meiosis 1:
- homologous chromosomes line up at the equator, then separate and move to opposite poles of the cell

meiosis 2:
- chromatids of each chromosome are pulled to opposite poles

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26
Q

Down syndrome

A
  • 1 in 1000 individuals
  • extra 21st (trisomy 21)
  • mild to moderate learning disabilities
  • almond shape to the eyes
  • shorter limbs, pore muscle tone
  • larger than normal space between big and 2nd toe
  • protruding tongue
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27
Q

what happens during fertilization?

A

2 gametes (n) fuse to form a zygote (2n)

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28
Q

in vitro fertilization

A
  • used when female Fallopian tubes are blocked (tube connects ovaries to uterus)
  • egg cells removed from ovaries and placed in Petri dish, fertilized eggs implanted into uterus few days after fertilization
  • more than one egg used, multiple births common
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29
Q

surrogacy

A

couple asks surrogate mother to carry embryo provided by couple, sometimes surrogate mother asked to produce egg

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30
Q

intracytoplasmic sperm injection

A
  • only one sperm cell in egg cell, zygote later inserted in female’s uterus
  • only 25% of ICSI procedures result in birth
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31
Q

advantages internal fertilization

A
  • embryo protected (inside female) & parents care for young –> more offspring survive
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32
Q

mesoderm

A
  • middle layer

- cells form kidneys, muscles, blood vessels, reproductive organs, bones

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33
Q

where does the genetic information in the zygote come from?

A

half from one parent, half from the other

n + n = 2n

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34
Q

artificial insemination

A
  • sperm collected and injected into female
  • widely used to breed farm animals
  • in humans, sometimes sperm collected from female’s partner and injected into female. sometimes, if male unable to produce enough viable sperm, sperm donor (usually anonymous) is used
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35
Q

how DNA can be affected

A
  • lost
  • duplicated
  • inverted (flipped)
  • moved within a chromosome
  • moved to another chromosome
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36
Q

how can pollen be transported?

A
  • colourful flowers attract pollinators which spread pollen as they take nectar from flowers
  • by the wind
  • for plants without flowers: pollen transported by wind from male cones to female cones
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37
Q

pollination

A
  • form of internal fertilization used by plants
  • transfer of male gametes in pollen from male reproductive part to female reproductive part
  • pollen tube forms to deliver sperm cells to egg cells once pollen lands on female part of plant (pistil)
  • after fertilization zygote grows into embryo, nourished by food within seed in which it grows (seed protects embryo)
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38
Q

assisted reproductive corrective technology procedures

A
  1. hormone therapy
  2. artificial insemination (AI)
  3. in vitro fertilization (IVF) {test tube baby}
  4. gametes intrafallopian transfer (GIFT)
  5. intracytoplasmic sperm injection (ICSI)
  6. oocyte cryopreservation
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39
Q

gametes

A

specialized cells necessary for reproduction

ex; eggs, sperm, pollen

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40
Q

why don’t large chromosome mutations usually pass down to new generations?

A

offspring doesn’t develop, doesn’t succeed, doesn’t reach reproductive age, or is infertile

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41
Q

first trimester

A

developing organ systems

  • brain, spinal cord forming (3 weeks) {4 mm}
  • digits, ears, organs, and muscles forming (6 weeks) {4 cm}
  • sexual differentiation (9 weeks) {9 cm}
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42
Q

what does sexual reproduction require?

A

two parents

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43
Q

what does haploid vs. diploid refer to?

A

the number of chromosomes

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44
Q

second trimester

A

growth

  • fetal movements felt (16-18 weeks) {20 cm}
  • eyelids open, fetus can survive with special care if born now (24 weeks) {35 cm}
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45
Q

males (gamete formation)

A

meiosis 1 - produces 2 cells

meiosis 2 - produces 4 cells with cytoplasm & organelles equally divided (4 haploid sperm cells

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46
Q

how are chromosome mutations caused?

A

by mutagens

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47
Q

endoderm

A
  • inner layer

- cells form lungs, lining of digestive system

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48
Q

stages of sexual reproduction

A
  1. mating (ritual)
  2. fertilization (external or internal)
  3. development
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49
Q

morula

A
  • end of first week

- embryo is 0.2mm in diameter

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50
Q

who are offspring genetically different from?

in sexual reproduction

A
  • each other
  • either parent
  • any other member of their species
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51
Q

what is meiosis?

A

the process that produces gametes with half the number of chromosomes as body cells

52
Q

external fertilization

A
  • occurs outside bodies of parents
  • gametes released by parents = fertilization happens when sperm and egg cell come in contact
  • common in underwater animals and animals who live in moist environments (water needed for male gamete to travel to female gamete)
53
Q

disadvantages internal fertlization

A
  • requires more energy to find mate

- produces fewer zygote

54
Q

fertilization

A

process when an egg cell is penetrated by a sperm cell and the haploid genetic information of both male and female gametes combine

55
Q

gamete formation

A

different in males and females

56
Q

once the egg is fertilized, when will cell division occur?

A
  • there are enough nutrients for rapidly dividing embryo
  • temperature warm enough for proteins and enzymes to function properly during chemical reactions in developing embryo
  • enough moisture so embryo doesn’t dry out
  • embryo protected from threats (predators and environment)
57
Q

internal fertilization

A
  • sperm cells deposited inside female body (where they meet egg cell)
  • one sperm penetrating egg cell results in membrane changing electrical charge that prevent more sperm from entering egg –> only one set of male chromosomes can unite with the chromosomes in the nucleus of the egg cell
58
Q

gametes intrafallopian transfer

A

egg cells removed from ovaries & placed in mixture of sperm, mixture placed in Fallopian tubes so fertilization can take place in woman’s body

59
Q

oocyte cryopreservation

A
  • woman’s eggs (oocytes) extracted, frozen and stored

- when she is ready to become pregnant, eggs thawed, fertilized, and transferred to uterus as embryos

60
Q

what does the zygote undergo to become an embryo?

A

mitosis and cell division

61
Q

diploid number

A

(2n)

two sets of chromosomes

62
Q

Klinefelter syndrome

A
  • 1 in 500 males
  • male with an extra ‘x’ chromosome (XXY)
  • small testicles –> reduced fertility
63
Q

when do whole chromosome mutations occur in meiosis 1?

A

if homologous chromosomes do not seperate

64
Q

disadvantages external fertilization

A
  • many gametes don’t survive outside of parent’s (usually female) body
  • zygotes and embryos not protected
  • parents don’t care for offspring –> few survive
65
Q

karyotypes

A

pictures of an organism’s chromosomes arranged in homologous pairs

66
Q

stages embryonic development

A
  1. Morula
  2. Blastula
  3. Gastrula
67
Q

genetic diversity

A

inherited genetic differences (variation) in a species that give many organisms a survival advantage

68
Q

when do whole chromosome mutations occur in meiosis 2?

A

if sister chromatids do not seperate

69
Q

telophase

A
  • spindle fibres disappear
  • nuclear membrane forms around each separated set of chromosomes
  • nucleolus appears
70
Q

how does asexual reproduction occur?

A

occurs without gametes (sex cells) coming together

71
Q

enzyme in stem cells?

A

enzyme telomerase

72
Q

why do cells divide?

A
  • cells receive nutrients & removes waste through cell membrane
  • size of cell membrane determines how much can enter/leave the cell
  • cells grow –> volume increases more quickly than surface area
  • once cell is certain size, membrane can’t support contents anymore
  • cells must divide to reach favourable surface/volume ration
  • when they get too big they divide
73
Q

reproductive cloning (adult DNA cloning)

A
  • produces a genetic duplicate of an organism
    • takes a nucleus from a cell (from the organism to be cloned) and puts it into an egg cell that has had the nucleus removed
74
Q

problems of reproductive cloning (adult DNA cloning)

A
  • only about 10% of clones survive
  • clone can be abnormally large/sized
  • clones have higher rates of cancer and infection
  • clones age faster than others
75
Q

do cancer cells function as parts of your body?

A

no, cancer cells are not specialized, they do not make proteins for organ cells.

76
Q

late prophase

A
  • nuclear membrane disappears

- spindle fibres finish forming and attach to centromeres or chromosomes

77
Q

what does telomerase do?

A

stop chromosomes from tangling/fraying with other chromosomes

78
Q

how does vegetative reproduction work?

A

grasses, lilacs, and many forms send out rhizomes (underground stems.)

some woody shrubs reproduce asexually by using their ordinary stems, branches of these plants take root wherever they touch the ground.
ex: currants, willows, and forsythias

some plants send out runners which are special stems (they have a small, new, genetically identical plant on them.) when new plant touches ground; it roots, forming a whole new plant.
ex: strawberries and spider plants

79
Q

early prophase

A
  • nucleolus disappears

- spindle fibres begin to form

80
Q

what is cancer?

A

certain diseases that result from uncontrolled cell division

81
Q

anaphase

A
  • spindle fibres pull sister chromatids to opposite poles of cell
82
Q

stomach lining cells are replaced every:

A

2 days

83
Q

disadvantages of vegetative reproduction

A
  • clones, or new plants, grow close to the parents (compete for same resource)
  • clones, or new plants are genetically identical. illness or disease could kill all of them
84
Q

why do cancer cells release chemicals to attract blood vessels?

A

blood vessels branch into tumour and deliver nutrients to it

85
Q

how can asexual reproduction be characterized?

A

a. only one parent is required
b. no gametes (sex cells) required
c. offspring are clones (same set of chromosomes)
d. no specialized reproductive cells or structures

86
Q

Five major types of asexual reproduction used by organisms:

A
  1. binary fission (bacteria)
  2. budding
  3. fragmentation
  4. vegetative reproduction
  5. spore formation
87
Q

mitosis

A

divides the duplicated contents of the nucleus into two equal parts

88
Q

what does therapeutic cloning require?

A

stem cells

  • cells that have not specialized yet –> have the potential to become different types of cells
  • can use adult stem cells or embryonic stem cells
89
Q

how do cancer cells escape programmed cell death? what does this mean for their chromosomes at cells division?

A

90 percent of human cancer cells don’t turn off telomerase gene. telomere caps of chromosomes do not shorten during cell division (divide longer than regular cells.)

90
Q

which are more desirable to use in therapeutic cloning? adult stem cells or embryonic stem cells? why?

A

embryonic are more desirable because they can be more types of cells

91
Q

benefits to humans of vegetative reproduction

A
  • food source (e.g. potatoes)
  • increase yield & speed of harvest
  • produce crops with specific qualities:
    • taste/texture
    • storage/handling
  • form single-celled spores (specialized reproductive cells)
    • have a nucleus, cytoplasm, and protective covering
    • covering protects spore from physical damage/drying out
    • carried away from parent by wind/water. when spore lands in favourable environment, it develops into a new organism through mitosis.
92
Q

how is therapeutic cloning used?

A

to correct health problems

93
Q

how many times can a human cell divide?

A

50 times

94
Q

skin cells are replaced every:

A

20 days

95
Q

three parts/phases of interphase

A
  • growth and preparation
  • DNA replication
  • growth and preparation continued
96
Q

in cytokinesis: the 2 nuclei are separated into ________________ that are ____________ the original cell.

A

2 daughter cells, identical to

97
Q

grafting

A
  • does not happen naturally. humans must make this happen.

- stems called sions are attached to the rooted stock of another species (quicker harvest)

98
Q

what are the 3 stages of the cell cycle?

A

interphase
mitosis
cytokinesis

99
Q

what monitors cell activity. why?

A

special proteins at the checkpoints monitor the cell activity and send this information to the nucleus.

100
Q

fragmentation

A

pieces of parent’s body breaks off. some fragments produce clones. sometimes occurs by accident. more often, it is deliberate.

ex: sea stars and flatworms reproduce by fragmentation

101
Q

how do cancer cells spread?

A

tumour cells break away and are carried by blood vessels to new location where they divide and form new tumour

102
Q

how can stem cells be used?

A

to replace damaged cells in patients with diabetes, spinal injuries, or Parkinson’s disease

103
Q

budding

A

offspring starts as growth/bud on the body of the parent as a result of repeated mitosis and cell divisions

104
Q

difference healthy cells cancer cells

A

healthy cells: grow in single layer, stop dividing when they stop receiving messages from nearby cells

cancer cells: don’t respond to messages, begin to grow in multiple layers

105
Q

define vegetative reproduction

A

only occurs in plants. form new plants without making seeds (without sexual reproduction)

106
Q

stages of interphase

A
  • growth and preparation
  • DNA replication
  • continued growth and preparation
107
Q

when are activities within the cell monitored/controlled?

A

at specific stages/checkpoints

108
Q

what cause mutations?

A

mutagens (viruses, x rays, ultraviolet light, and chemicals such as acetone in cigarettes.

109
Q

phases of mitosis

A
early prophase
late prophase
metaphase
anaphase
telophase
110
Q

brain cells are replaced every:

A

30-50 years

111
Q

binary fission

A

organism splits in two roughly equal halves, pinches off (cytokinesis) to form two new organisms. mitosis not necessary because no nucleus in bacteria. single dna just replicates.

112
Q

what happens when a cell is exposed to radiation during mitosis?

A

chromosomes fail to move to opposite poles of a cell during anaphase

113
Q

What is cloning?

A

cloning is the process of making a genetically identical organism through nonsexual means

114
Q

what happens before mitosis?

A

DNA molecules that replicated during interphase join to form sister chromatids of a chromosome joined by a centromere

115
Q

cytokinesis in animal cells

A

the cell membrane pinches together

116
Q

metaphase

A
  • spindle fibres pull chromosomes into line at equator
117
Q

interphase

A
  • cell increases in size, makes protein (carries out the functions necessary for survival)
  • cells copy/replicate itself and 3 billion base pairs of DNA information. DNA ladder break apart, new bases pair with bases on original DNA
  • cells make proteins for new daughter cells formed after cytokinesis. chromatin (containing replicated DNA) is loosely coiled. dna copied into rna. organelles duplicated. two new identical dna molecules produced
118
Q

what if a mutation occurred in a gene producing instructions for a checkpoint protein?

A

cell cycle control will be lost. damaged cells may divide uncontrollably.

119
Q

what treatment are cancer researchers looking for?

A

drugs that work by blocking cel division in a cancer cell and preventing formation of tumours

120
Q

uses of human assisted cloning?

A
  • to save genetic information from endangered species
  • to mass-produce an organism with a desirable trait
    • (for example pine trees that are resistant to pine beetles)
121
Q

what are embryonic cells? how long can they live for?

A

early stage cells of developing embryo. indefinitely.

122
Q

what happens to nuclei of cancer cells? why?

A

become large and abnormal because cell division no longer functions and chromosomes do not divide correctly.

123
Q

when/why do embryonic stem cells lose their “fountain of youth?”

A

once a cell becomes specialized

124
Q

cytokinesis in plant cells

A

a cell plate forms

125
Q

what does asexual reproduction mean?

A

without sex

126
Q

clone

A

identical genetic copy of its parent

127
Q

cytokinesis

A

separates the two nuclei and cell contents into two daughter cells

128
Q

when will cells not divide?

A
  • not enough nutrients to support cell growth
  • dna in nucleus not replicated
  • dna damaged

ex; chromosomes not attached to spindle fibres in metaphase, chromosomes not moved to poles in anaphase