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Flashcards in Midterm 2 Deck (140):
1

Homologous chromosomes

A set of chromosomes, one maternal and one paternal that pair up during meiosis. They contain the same genes but not necessarily the same alleles

2

Interphase 1

The cell prepares for cell division, DNA is synthesized

3

Prometaphase 1

Nuclear envelope disappears. One kinetochore forms, microtubules grow from centromere

4

Metaphase 1

Chromosomes line up side-by-side in the center of the cell

5

Cytokinesis 1

The cell divides into two 2n cells

6

Metaphase 2

Chromatids line up

7

Cytokinesis 2

The cell divides into two haploid cells

8

How does meiosis differ from mitosis

Meiosis results in four nuclei by two divisions that are haploid. The nuclei in meiosis are not identical after division. The chromatids are arranged side-by-side, not up and down and there can be crossover.

9

In humans, what is the difference between spermatogenesis and oogenesis?

Spermatogenesis creates four sperm, oogenesis creates 1 ovum and three polar bodies

10

What is the difference between a somatic cell and a gamete?

A somatic cell is diploid, a gamete is haploid.

11

Law of segregation

1)alternative versions of genes account for variations in inherited traits-alleles
2)an organism inherits two copies of a gene, one from each parent
3)the dominant allele determines appearance
4)the two alleles for a characteristic end up in different gametes

12

Law of independent assortment

Each pair of genes sort independently into gametes, so you just account for all possibilities

13

Autosomal traits

Non-sex chromosomes, we have 22

14

Sex-linked traits

Carried on the x and y chromosom s

15

Somatic cells

Body cells

16

Chromosomes

Structure that carries genes, we have 23. Each code for different traits

17

Chromatin

Nucleic acids that condense to form a chromosome

18

Spindle apparatus

Network of tubules that separates chromatids

19

Chromatids

One of the two strands that a chromosome divides into

20

Centrosome

The organelle that contains the centrioles

21

Centromere

The part of a chromosome that links sister chromatids

22

Ploidy

The number of copies of homologous chromosomes

23

Haploid

A complete set

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Diploid

2 complete sets

25

Aneuploidy

The presence of an abnormal number of chromosomes in a cell

26

Zygote

A fertilized ovum, a diploid cell resulting from the fusion of two haploid gametes

27

Homologous chromosomes

One set of maternal and one set of paternal chromosomes that pair up during meiosis

28

Synapsis

Takes place during prophase 1, the matching up of two homologous chromosomes

29

Crossing over

Because the homologous chromosomes are so close, they exchange some information

30

Non-disjunction mutation

The failure of homologous chromosomes to separate properly during cell division that results in abnormal chromosome numbers(aneuploidy) ex: Down syndrome

31

Parental generation

The primary set of parents crossed

32

First filial generation

First offspring

33

Second filial generation

Offspring of offspring

34

Dominant

The gene that is expressed

35

Recessive

The gene that has to be homozygous to be expressed

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Phenotype

The trait expressed

37

Genotype

The alleles present in the offspring

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Homeozygous(genotype)

AA or aa, the same alleles

39

Heterozygous(genotype)

Aa, different alleles

40

Pedigree charts

Diagram that shows the appearance of a particular gene

41

Conditions that would have led to formation of the first unicellular life form

The environment was reducing so organic molecules could spontaneously form. Phospholipids formed proto-cells

42

19th century scientists conclusions about the nature of life forms and our current atmosphere

Our current atmosphere is oxidizing, 4.5-3.5 billion years ago it was reducing so organic molecules could form. Life forms are carbon-based. Life forms represent order, so they are maintained at the expense of energy productions. Life comes from life

43

Haldane and oparin

Proposed the original environment was reducing not oxidizing so complex molecules are formed spontaneously. It is intrinsic to the nature of carbon that it will form polymers

44

Reducing vs. oxidizing environment

A reducing environment allows complex molecules to form spontaneously, oxidizing is towards break down b/c free radicals

45

What features make the earth a suitable place for life forms?

Water, reducing atmosphere, distance from sun, mass

46

What was the purpose of the Miller/Urey experiment?

In a reducing environment, they made glucose and amino acids. They showed the abiotic production of organic molecules

47

What is the relationship between carbonaceous chondrites and the abiotic production of organic molecules

Carbonaceous chondrites spontaneously form organic molecules if energy is added

48

Abiotic

Devoid of life

49

Evidence for life

Stromatolites form from bacteria and they date back 3 billion years ago

50

Heterotrophs

Unable to create its own food, must rely on consumption of other organisms

51

Autograph

Photosynthetic, self-sustainable, creates its own food

52

How does the photosynthetic mechanism in green/sulfur bacteria differ from blue/green bacteria

Green sulfur produces glucose and sulfur, blue/green bacteria produces oxygen and water

53

What were the ramifications of blue/green bacteria developing photosynthesis

The environment shifted to oxidizing and metals soaked up oxygen

54

What do deposits of red belt reveal to you?

There was oxygen and metal ions in the oxygen 3 billion years ago

55

What were the ramifications of the atmosphere shifting to oxidizing for prokaryotes?

There was mass extinction, anaerobic organisms either died or moved to anaerobic environments. Prokaryotes with electron transport chains used oxygen as a final electron acceptor and could survive

56

Endosymbiosis

Proto-eukaryotes used endosymbiosis to eat a proto-mitochondrion and form an Enzo-symbionts that can live in a o2 toxic environment

57

Selective advantage of endosymbiosis for the endosymbiont

Can detoxify oxygen and run ATP synthase

58

Bacteria

Prokaryote with bigger ribosomes and RNA is closer to us vs. archaea

59

Archaea

Primitive prokaryotes

60

Eukarya

Membrane bound sub compartments, unicellular or multicellular

61

Protista

Unicellular eukaryotes, including autotrophs, heterotrophs, highly sophisticated organelles

62

Fungi

Single-felled or multicellular, non-photosynthetic heterotrophs, have a cell wall, but primarily chitin. Saprophytes decompose organic matter

63

Multicellular life-forms

About 1 billion years ago

64

Features that unite all organisms in kingdom plantae

Multicellular eukaryotes, aerobic, use glucose as primary metabolite, photosynthetic autotrophs, all cells surrounded by a cell wall made of cellulose, aquatic or terrestrial, sedentary

65

Features of plant eukaryotes cells

Rod shaped dna, circular DNA in mitochondria and chloroplast, cell wall, plasma membrane, cytoplasm, nucleus with double membrane, nucleolus, ER, golgi, mitochondrion, chloroplast, lysosomes, large vacuole

66

Where would you find DNA in plant cells

In the chloroplast, mitochondria, and nucleus

67

Where would you find ribosomes?

On the rough ER, cytoplasm, chloroplasts, mitochondria

68

What types of ribosomes are there?

Free ribosomes and attached ribosomes

69

What are the features of the plant cell wall?

They have rivets to connect to other cell walls and extra cellular fluid

70

Vascular vs. no vascular plants

Vascular plants have vascular systems such as xylem and phloem, nonvascukar plants do not have these systems

71

Spores vs. gametes

Gamete is a sex cell with haploid, spore is a full set of chromosomes and can germinate to become a full plant

72

Why does H2O move into a bryophyte cell?

Diffusion

73

How do fades enter a bryophyte cell?

Diffusion

74

Is there a vascular network in bryophytes for moving water, gases, and nutrients between cells?

No just diffusion

75

Features of the cuticle of vascular plants

Waxy covering in the surface of the cell. The cuticle blocks the diffusion of H2O and gases into and out of the plant. The sonata is a small opening for gas exchange and water movement into and out of the plant

76

On a stomata, what are guard cells?

The guard cells control gas exchange from the stoma. Between there is a stoma pore

77

How does a stem on a fern differ from the trunk of a gymnosperm? What features do these structures share in common?

The trunk is non photosynthetic, the outer covering is dead cells called bark: gymnosperms have extensive root systems, ferns do not. Leaves of ferns are not shed

78

What is fruit

An ovary

79

Photosynthetic autotroph

Organism able to produce its own food through photosynthesis

80

Chloroplast

Organelles where photosynthesis occurs

81

Chlorophyll

Green pigment found in plants that allows plants to absorb energy from light

82

Cellulose

The major structural component of cell walls

83

Algae

Range of organisms that lack stomata, xylem, and phloem so non-vascular, moss and bryophytes, algarrobos

84

Vascular plants

Have xylem and phloem, CERN's, misses, conifers, angiosperms, gymnosperms

85

Xylem

One way only, carries water and minerals in vascular plants

86

Phloem

Two-way flow, carries water and food

87

Alternation of generations

Process of reproduction in plants

88

Archegonium

Organ of gametophyte that contains the ovum, haploid

89

Hermaphrodite

Has both male and female sexes

90

Megastrobulus

Ovules are contained here in gymnosperms

91

Microstrobulus

Cone containing pollen

92

Megasporocyte

Structure that produces mega spores

93

Pollen grain

Single cells that pollen is composed of

94

Winged seed

Allows seed to be airborne

95

Sepal

Protects the flower in bud and supports

96

Petal

Modified colored leaves that attract bees to carry pollen

97

Pistal

The female organs of the flower

98

Ovary

Contains ovum in flower

99

Style

Slender tube that connects stigma to ovary

100

Stigma

Receptive tip that receives pollen and where pollen grain germinates

101

Anther

The part of the stamen that contains the pollen

102

Microspores

The smaller type of spore produced by ferns

103

Polar nuclei

One of the two nuclei that eventually fuse to form endosperm

104

Egg

Contained in ovule

105

Sperm

Goes through ovary to get to egg

106

Double fertilization

Two sperms travel down style, one fuses with an egg and the other with polar nuclei

107

Zygote

Fertilized egg divides to form and embryo which is kept in seed until the right conditions arise

108

Endosperm

Nutritive tissue that can provide food for the developing plant

109

Seed

Contains embryo

110

Aristotle beliefs

There is a hierarchical way to nature, higher and lower animals

111

Is any species more evolved than others?

No

112

Baron Cuvier four groups

Radiata-circular animals, articulate-segmented animals, mollusca-animals with a shell and brain, vertebrate-bony skeleton, muscular hear, red blood

113

Lamarck belief

Inheritance of acquired characteristics, individual evolution. Ex: giraffes have long necks because they stretch them

114

Who originally organized things as trees

Haeckel

115

What is a phylum?

A group of animals that have a common body plan

116

Phylum chordata

Vertabrates, notochord, hollow nerve chord, pharyngeal gill slits

117

How many phylums of animals are there?

30-35

118

What is an animal?

Animals are eukaryotes, lack a cell wall, diploid body form, multicellular, mobile, use sexual reproductions, heterotrophs with internal cavity

119

Choanoflaggeletes

Closest known single celled relatives of animals

120

Isogamy

The female and male have the same size

121

What is special about bedfellows rodillera?

The have lost sex

122

How do females reproduce?

Parthogenesis. Males have not been observed

123

Developmental sequence of most animals

Zygote, eight cell stage, blastula, blastocoel, gastrilation

124

What are the three germ layers?

Ectoderm, mesoderm, endoderm

125

What is osmoheterotrophy?

Directly from environment into cells

126

What does it mean to be phagocytic?

Cells that ingest foreign particles

127

What does it mean to be a typical animal

The cell membrane contains cholesterol, neurons and muscles are unique to animals, epithelial tissues are in all animals, unique cell junctions

128

Genomic features of animals

Mitochondrial genomes are greatly reduced

129

Two supergroups of animals

Non-bilateral and bilateral

130

Germ layers of non-bilaterians vs. bilaterians

Non-bilaterians have two embryonic germ layers, bilaterians have three embryonic germ levels

131

Coelomates vs. pseudocoelomates vs. acoelomates

Coelomates-fluid filled cavity, pseudocoelomates-reduced fluid filled cavity, acoelomates-no body cavity

132

Four major groups of bilaterians

Xenacoelomorpha(some worms), spiralia/lophotrochozoa(other worms, molluscs, moss animals), ecdysozoa(more worms, insects, crabs, spiders), deuterostomia(even more worms, starfish, urchins, tunicates, vertebrates)

133

Which organisms are in phylum porifera?

The sponges

134

What are the characteristics of phylum porifera?

Marine and freshwater, sexual and asexual reproduction, assymetrical, vascular system, fiber skeleton made of spongin

135

What is phylum Ctenophora?

Comb jellies that eat plankton, have rotational symmetry

136

What are defining characteristics of phylum placozoa?

They have no symmetry, dorsal central polarity, no muscles, nerves or gut, asexually reproductive, move by ciliary locomotion

137

Main characteristics of phylum Cnidaria(anemones, corals, and jellyfish)

Mostly radial symmetrical, incomplete gut, indirect sexual development, asexual development by budding, nematocysts, have neurons and muscles

138

Xenacoelomorpha characteristics

Incomplete guts, bilateral symmetry, direct development, sensory structures of single-felled ocelli and statocyst

139

Ecdysozoa characteristics

Have cuticle that can be shed, the blastopore turns into mouth, first group of protostomes

140

Lophotrochozoa classification

Complete guy, well developed systems, indirect development, bilaterians, two main groups: lophophorates and trochozoans, annelid worms and some snails