Test 3 Flashcards Preview

Biology > Test 3 > Flashcards

Flashcards in Test 3 Deck (89):
1

Type of cellular reproduction for Archaea and bacteria

Binary fission (asexual)

2

Eukaryotes have to Types of cell reproduction.

Mitotic and meiotic cell devision

3

Somatic (body) cells

Mitotic cell devision

4

Sex cells
-sperm
-eggs
-pollen

Meiotic cell devision

5

-asexual reproduction
-split into two separate cells
-most basic form of cell division.
:cells copy DNA then divide
:can happen every 20min under optimal conditions

Binary fission

6

-mats of bacteria
(The plaque on your teeth)

Biofilms

7

When bacterial density reaches a certain level behavior changes
– Bioluminescence in bobtail squid (Vibrio fisheri)

Quorum sensing

8

Why do tropical regions specialize in spicy food?
• Many peppers have antimicrobial properties
• Refrigerators are a relatively new invention
• Spices help repel bacteria which grow better in hot climates
• Try eating some spicy food when you’re sick

Spicy food

9

– Nuclear division => Mitosis (technically)
– Cellular division => Cytokinesis

Eukaryotes: Mitotic Cell Division
• Definition?

10

– Development (differentiation of cell types)
• Cells differentiate due to gene expression
– Growth (increases in cell number)
• Note this is one way to grow, not the only way
– Repair and maintenance of tissues
– Asexual reproduction in some organisms

Eukaryotes: Mitotic Cell Division

11

• Theformationofoffspring without the union of male and female gametes
• Whymightthisbeuseful?
– Nature has been practicing cloning for millions of years
• Protists
• Sponges
• Hydra and other Cnidarians
• Echinoderms (sea stars)
• Some plants
• Some lizard species...

Eukaryotes: Asexual Reproduction

12

• Interphase accounts for __% of the cell cycle

90

13

The Mitotic phase includes ________ and _________.

Mitosis
Cytokinesis

14

Cell growth (G1)
Division preparation

Interphase

15

Produce proteins and cytoplasmic organelles

Cell growth (G1)

16

– Copies chromosomes (S phase)
– Prepares for cell division (G2 phase)

Division preparation

17

Copies chromosomes

S phase

18

Preparation for cell devision

G2 phase

19

The genetic information of a cell – Entire DNA of cell or organism

Genome

20

is the DNA/Histonecomplex – The yarn

Chromatin

21

are portions of DNA+histones – Specific portions of chromatin

Chromosomes

22

are pairs of IDENTICAL chromosomes
– Term used for mitosis/meiosis
– NOT the same thing as homologous chromosomes
• 1 Mom/1Dad chromosome vs. 2 Mom chromosomes

Chromatids

23

– Happens at Chromatin stage

• DNA duplication/DNA synthesis

24

Afterduplication
– Chromatin condenses into smaller packages
– Double the DNA

Chromosomes

25

– Made of two chromatids

Duplicated Chromosome

26

Every species has a characteristic chromosome number (n)
– Humans __ pairs
– Chimps __ pairs
– Fruit fly __ pairs
– Dogs have __ pairs

23
24
4
39

27

DNA strands are long – Up to _ feet in humans – Per cell!

6

28

When the cell carries out it’s functions, replicates it’s DNA, and grows

Interphase

29

Stage of mitosis when chromosomes condense and the mitotic spindle begins to form

Prophase

30

Of meiosis 1, when chromosomes condense and become visible, and crossing over occurs

Prophase 1

31

Meiosis 2, when chromosomes condense and become visible

Prophase 2

32

Stage of mitosis, when the nuclear membrane breaks up and spindle fibers attach to kinetochores

Prometaphase

33

Stage of mitosis in which chromosomes are aligned down the center of a cell

Metaphase

34

Meiosis 1, when homologous chromosome pairs align down the center of a cell

Metaphase 1

35

Meiosis 2, when replicated chromosomes align down the center of a cell

Metaphase 2

36

Stage of mitosis in which the spindle pulls sister chromatids toward opposite poles of the cell.

Anaphase

37

Meiosis 1, when spindle fibers pull homologous chromosomes toward opposite poles of the cell.

Anaphase 1

38

Meiosis 2, when centromeres split and spindle fibers pull sister chromatids toward opposite poles of the cell

Anaphase 2

39

Stage of mitosis in which chromosomes arrive at opposite poles and nuclear envelopes form

Telophase

40

Meiosis 1, when homologs arrive at opposite poles

Telophase 1

41

Meiosis 2, when chromosomes arrive at opposite poles and nuclear envelopes form

Telophase 2

42

Destruction of cytoplasm into daughter cells in cell division

Cytokinesis

43

Occurs during telophase
– After chromosomes have divided
Vesicles from the Golgi unite at the metaphase plate
Form Cell Plate
Membranes fuse and grow towards existing cell wall
Contents in vesicles form new cell wall

Cytokinesis in plant cells.

44

– Produce all their eggs by age 0
– Cells arrested at meiosis I until puberty
– Less than 400 viable eggs produced in lifetime
– Largest human cell
• Visible with naked eye

Female gametes

45

– Produce roughly 85 million sperm a day
– Can produce 1 quadrillion in a lifetime (1011)
– ~200 million per ejaculation
• Most die instantly
– The individual male is biologically superfluous

Male gametes

46

____ do not respond normally to the body’s control mechanisms ___ may not need growth factors to grow and divide
– They may make their own growth factor
– They may convey a growth factor’s signal without the presence of the growth factor
– They may have an abnormal cell cycle control system

Cancer cells

47

A normal cell is converted to a cancerous cell by a process called

Transformation

48

Masses of abnormal cells within otherwise normal tissue

Tumor

49

______ invade surrounding tissues and can __________, exporting cancer cells to other parts of the body, where they may form additional tumors

Malignant tumors
Metastasize

50

are cancer-causing genes

Oncogenes

51

are the corresponding normal cellular genes that are responsible for normal cell growth and division

Proto-oncogenes

52

____ genes help prevent uncontrolled cell growth
– p53 is an example

Tumor-suppressor

53

– Repair damaged DNA
– Control cell adhesion
– Inhibit the cell cycle in the cell-signaling pathway

Tumor-suppressor proteins

54

When chromosomes or chromatids are separated they are

disjoined

55

If nondisjunction occurs during meiosis I, ___ gametes will be affected.

ALL

56

If nondisjunction occurs during meiosis II, only ___ of the gametes will be affected.

1/2

57

– a way of visualizing the chromosomes of an individual
-number
-appearance

Karyotypes

58

are often used to diagnose conditions before a child is born.

karyotypes

59

Cells are harvested from the amniotic fluid surrounding a fetus

amniocentesis procedure

60

A special stain called _____ stain is used to visualize the band on chromosomes

Giemsa

61

– 22 autosomes
– 1 Y chromosome – 1 X chromosome

Human males

62

-22 autosomes
- 2 X chromosomes

Human females

63

Autism is also known as

Also known as trisomy 21

64

There are several conditions due to abnormal numbers of sex chromosomes:

-Triple X syndrome
– Klinefelters
– Turners

65

Researchers can also use _______ ______ _____ to more easily distinguish between the chromosomes

multicolored fluorescent tags

66

____ what the organism looks like
• Genetic cause
• Environmental cause

Phenotype

67

What genes you actually have

Genotype

68

– Raw material for Evolution by Natural Selection

Genetic variation

69

– Austrian Monk
– First to systematically record genetic studies
– *Formulated fundamental principles of genetics
– Without knowing about DNA or meiosis!
– Chuck never read his work

Gregor Mendel (1822-1884)

70

-Have male and female parts in same flower
• Can self-fertilize
• Possess many variable traits
• Can be easily grown and manipulated

Why Mendel chose garden peas

71

• Monohybrid cross
• Dihybrid cross
• Mendel actually performed many more types

Two Types of Experiments Mendel performed

72

• Cross between 2 true- breeding plants that differ in 1 trait

Monohybrid crosses

73

____:Two copies of same allele
– ______ dominant = PP
– ____ recessive = pp
– *References specific allele type
• *__________ dominant for “X” allele

Homozygous

74

______: one dominant, one recessive allele present
– Pp

Heterozygous

75

• A mating of individuals differing at two genetic loci
– Typically, this means individuals that are hybrid at each of two loci
– But could be two true breeding individuals
• R=round seed, r=wrinkled
• Y=yellow seed, y=green

Dihybrid Cross

76

• What is the phenotypic ratio of F2?
– ___ possible combinations
–______ ratio

4
9:3:3:1

77

– Allele pairs segregate independently of others
– *R doesn’t always pair with Y (it could pair with y)

Mendel’s principle of independent assortment

78

• Alleles on homologous chromosomes separate into gametes

Law of segregation

79

• Allele pairs separate from others independently.

Law of independent assortment

80

Closer genes are on a _____ more likely they are inherited together

chromosome

81

• Heterozygotes have an appearance in between the parent types
• Dominant trait “diminished”
-often a dosage issue

Incomplete Dominance

82

• Different from incomplete dominance
– Dominant trait at >100%
• Both dominant alleles expressed
– Traits at 100%
– Not enough ‘space” to completely take over

Codominance

83

A single gene affects more than one phenotypic trait

Pleiotropy

84

– Mutations in one gene that codes for a specific enzyme
– Mental retardation
– Reduced hair and skin pigmentation
– Autosomal recessive trait

Phenylketonuria (PKU)

85

• The presence of an allele at one gene affects the expression of a different gene
• Hair color in in different species is a common example

Epistasis

86

• Multiple Genes one trait – Additive effect
– Opposite of Pleiotropy – Skin color & Height

Polygenic Inheritance

87

• Sex chromosomes carry other genes also
– *Not related to gender determination
• Genes usually located on X-chromosome – No corresponding gene on the Y-chromosome
• Males inherit the gene only through their mother – Will always express same phenotype
– Father’s genotype doesn’t matter

Sex-linkage

88

Examples of X-linked traits, All are recessive traits
• Most common in males
– They only need to inherit one copy

– Red-green colorblindness
– Hemophilia
– Duchenne muscular dystrophy

89

• In mammalian females, one of the two X chromosomes in each cell is randomly inactivated during embryonic development
• The inactive X condenses into a ________ ________
• If a female is heterozygous for a particular gene located on the X chromosome, she will be a mosaic for that character

X Inactivation in Female Mammals
Barr body