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AP Biology Mr. Maiorana > Chapter 27/28 test > Flashcards

Chapter 27/28 test Flashcards

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1
Q

What present day organism is similar to what animals evolved from?

A

Single celled eukaryotes present to choanoflagellates

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2
Q

How many species have been discovered and what is the predicted actual number?

A

1.3 million discovered and actual estimate of 8 million

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3
Q

What are Edicaran Biota?

A

560 million year old fossils that are members of an early group of soft bodied multicellular eukaryotes

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4
Q

What is the sponges’ status on the phylogenetic tree of animals?

A

They are said to be basal animals because their lineage originates near to roots of the tree

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5
Q

What are choanocytes? Which cells do they resemble?

A

aka collar cells, they engulf food bacteria and other particles via phagocytosis. The interior of the body of a sponge is lined with these cells. They resemble choanoflagellates

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6
Q

What are animals thought to have evolved from?

A

a choanoflagellate-like ancestor

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7
Q

What are amoebocytes?

A

Mobiles cells used by sponges, named for their use of pseuodpodia. They move around the cell, take up food from water and choanocytes, digest it and carry nutrients to other cells

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8
Q

What is the basic morphology of a cnidarian?

A

A sac with a central digestive compartment/gastrovascular cavity with a single opening

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9
Q

What are feeding characteristics of cnidarians?

A

They are carnivores that often used tentacles situated in a ring around their mouth to capture and pass food through the gastrovascular cavity. Enzymes secreted into the cavity turn the food into a nutrient rich broth and cells lining the cavity absorb nutrients and waste is expelled

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10
Q

Describe the neural systems of cnidarians.

A

The have very simple forms of nerves/muscles. Movement is coordinated by a noncentralized nerve net distributed throughout the body. They have no brain and can detect and respond to stimuli from all directions

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11
Q

What are bilaterians?

A

Most of the fossils from the Cambrian explosion, bilaterians are an enormous clade whose members have a complete digestive tract and a two-sided, bilaterally symmetric form

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12
Q

What types of fossils emerged during the cambrian explosion?

A

fossils with hard tissue that hunted prey

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13
Q

Why are hypotheses as to why diversity of Ediacaran life forms decrease during the cambrian explosion?

A

Natural selection led to a decrease of these organisms, an increase in atmospheric oxygen, and the appearance of Hox genes and other genetic changes affecting the regulation of developmental genes facilitated the evolution of new body forms

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14
Q

What is radial symmetry?

A

Are symmetrical when sliced through the center with a straight line

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15
Q

What do dorsal and ventral mean?

A

Dorsal: Top
Ventral: Bottom

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16
Q

What are neural characteristics of animals with a bilateral symmetry plan?

A

Many of them have sensory equipment in the anterior end and a central nervous system/brain in the head

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17
Q

How mobile or radial animals compared to bilateral animals?

A

Radial: Live attached to something or drift/weakly swim

Bilateral: Move actively from place to place

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18
Q

What are the ectoderm and endoderm? Where are they present?

A

Ectoderm: the germ layer covering the outer surface of the embryo, gives rise to the outer covering of the animal, and for some animals, the central nervous system

Endoderm: inner most germ layer, gives rise to the lining of the digestive tract and organs such as lungs and livers of vertebrates

Present in all animals with true tissues

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19
Q

What is the mesoderm? where is it present?

A

All bilateral animals have a mesoderm. It is a third germ layer that fills much of the space between the ectoderm and endoderm, forming the muscle and most other organs between the digestive tract and outer covering of the animal

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20
Q

What is a body cavity?

A

a fluid or air filled space located between the digestive tract and outer wall. It has fluid cushions that suspend organs to prevent internal injury, it contains noncompressible fluid that acts as a skeleton against which muscles can work in soft bodied animals, and it enables internal organs to grow and move independently of the outer body wall

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21
Q

What allows us to study evolutionary relationships among living animals?

A

rRNA, Hox genes, protein coding nuclear genes, mitochondrial genes and morphological traits

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22
Q

What is eumetozoa? What are basal eumetazoa like?

A

A clade of animals with true tissues, containing all animals except sponges and a few others. Basal eumetazoans have 2 germ layers and radial symmetry

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23
Q

What is bilateria?

A

A clade containing most animal phyla. Defined by bilateral symmetry and 3 germ layers. Their rapid diversification occurred during the cambrian explosions

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24
Q

What is the biggest of the phyla on earth?

A

Arthropods

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25
Why have arthropods been successful?
Their segmented body, exoskeleton, and jointed appendages
26
How did arthropods change as they evolved?
They went from having little variation in body segments to having a more efficient body plan and having more variety among separate segments
27
What do scientists think drove the evolution of arthropods?
Changes in sequence or regulation of Hox genes
28
What phylum do vertebrates belong to?
Chordata
29
What body plan do chordates have?
bilateral
30
What are the 4 key characteristics of chordates?
1. A dorsal, hollow nerve chord: unique structure that develops into the brain/spinal chord 2. Pharyngeal slits/clefts: structures in adults the function in filter feeding in gills or the head 3. Notochord: flexible rod providing skeletal support 4. Post anal tail: Muscular post anal tail
31
What do other animals have instead of a dorsal, hollow nerve chord?
A ventral, solid nerve chord
32
What major evolutionary step came after the main body plan in chordates?
Vertebrates with a well defined head with a skull, eyes, brain and other sensory organs
33
What were vertebrates mor efficient at than their ancestors?
Capturing food and avoiding being eaten
34
What are gnathostomes? Why did they succeed?
Jawed vertebrates. They succeeded because their paired fins and tail allowed them to swim well, their jaws allowed them to grab and bite prey
35
What are chondrichthyans?
A clade including sharks, rays and their relatives. They are some of the biggest and most successful vertebrate predators in the ocean. They have a skeleton composed mostly of cartilage(name means cartilage fish)
36
What are osteichthyes and their main lineages?
A clade consisting of the vast majority of vertebrates. The typically have a bonu endoskeleton, lungs or lung derivatives. Most of them have bony rays that support their fins. There are also vertebrates in this clade with lobe fins, fins with rod shaped bones surrounded by a thick layer of muscle in their fins
37
What are tetrapods?
Vertebrates with limbs and digits
38
Which group first colonized land according to fossil evidence?
Arthropods
39
What is the ancestor of land plants?
Green algea
40
What is a cuticle?
The covering of the body of an arthropod, an exoskeleton made of layer and protein and chitin. It can thick and hard or thin and flexible
41
What diversified insects?
Increased diversity in plants
42
What body part evolved that allowed animals to colonize land?
lone fins evolved into limbs and feet in tetrapods
43
What is the importance of discovered tiktaaliks?
They have allowed paleontologists to reconstruct how fins became progressively more limb like over time, revealing the appearance of the first tetrapods
44
How did tetrapods rise?
It was a body modification for species in devonian coastland where water was shallow and oxygen poor
45
What are amniotes?
a group of tetrapods whose extant members are reptiles, birds and mammals. They get their name from producing an amniotic egg with 4 membranes
46
What is the use of an amniotic egg?
It was an adaptation to terrestrial life, allowing an embryo to develop on land in its own private pond
47
What are the meaning of the word ectothermic and endothermic?
Ectothermic: The animal absorbs external heat as its main source of body heat Endothermic: They maintain their own body temperature through metabolism
48
What are synapsids?
The group of amniotes which mammals originated from. Early nonmamallian synapsids lacked hair, had a sprawling gait and laid eggs
49
What are the 3 major lineages of mammals?
Monotremes: egg laying Marsupials: Mammals with a pouch Eutherians: Placental mammals
50
When did mammals diversify?
After the extinction of dinosaurs
51
How did marine ecosystems change with the rise of animals?
The waters became clearer and less dominated by cyanobacteria as organisms that ate producer rose
52
What clades are angiosperms split into?
Monocots: have a single cotyledon as an embryo Eudicots: two cotyledons as an embryo
53
How do monocots and eudicots differ in leaf venation, stems, roots, Pollen and flowers?
Monocots: Veins are parallel, vascular stem tissue is scattered, no main root in root system(fibrious), pollen grains have one opening, floral organs in multiples of three Edicots: Netlike veins, vascular tissue arranged in a ring, tap(main) root present, pollen grain has 3 openings, floral organs in multiples of 4 or 5
54
What consists of a shoot system in plants?
Stems and leaves
55
What kinds of plants usually have a taproot system?
Tall, erect plants with large shoot masses
56
What are the roles of taproots and lateral roots?
Taproots: Allows the plant to be taller and access better light conditions Lateral roots: Absorption
57
What are mycorrhizal associations?
Symbiotic interactions formed between most terrestrial plant root systems and soil fungi to increase a plant’s ability to absorb minerals
58
What are nodes and internodes?
Nodes are the points at which the leaves are attached and internodes are the stem segments between the nodes
59
What is an apical bud?
Located at the shoot tip, it is composed of developing leaves and a compact series of nodes and internodes
60
What is an axillary bud?
A structure found in shoots that can potentially form a lateral branch, thorn or flower
61
What do leaves consist of usually?
A flattened blade and a petiole which joins the leaf and to the stem at a node
62
What types of tissues are plant organs composed of?
Dermal: The plant’s outer protective covering Vascular: Facilitate transport of materials through the plant and to provide mechanical support Ground tissues: Non vascular or dermal tissues
63
What is the epidermis?
A single tissue layer of tightly packed cells in nonwoody plants, and it has specialized characteristics in each organ
64
What is the cuticle?
a waxy coating on the epidermal surface in leaves and most stems to help prevent water loss
65
What is the periderm?
A protective tissue in woody plants that replace the epidermis in older regions of stems and roots
66
What are the xylem and phloem?
The 2 types of vascular tissues. The xylem conducts water and dissolved minerals upward from the roots into the shoots and the phloem transport sugars and the products of photosynthesis from where they are made to where they are needed
67
What is the stele?
The vascular tissue of a root or stem is collectively called the stele
68
What are pith and cortex?
Pith: Ground tissue that is internal to vascular tissues Cortex: Ground tissue that is external to vascular tissue
69
What is the function of the ground tissue system?
Photosynthesis, short system transport, storage and support
70
What are parenchyma cells?
Have thin and flexible primary walls, lack secondary walls. Perform metabolic functions, synthesizing and storing organic products using a large central vacuole in the cell.
71
What are collenchyma cells?
Grouped in strands, support young parts of the plant shoot. They’re elongated and have thicker primary walls, walls are unevenly thickened. They offer support without restraining growth. Found in epidermis below young petioles and stems
72
What are Sclerenchyma cells?
Supporting elements in a plant, more rigid than collenchyma cells. They have a thick cell wall containing lignin(indigestible strengthening polymer)after elongation has ceased. Found in regions of the plant that are done growing. They are so specialized that many die and leave secondary skeleton walls.
73
Where is lignin present?
All vascular plants but not bryophytes
74
What are the two types of sclerenchyma cells?
Sclereids: Have a boxier and irregular shape. Very thick and lignified secondary walls. Fibers: Grouped in strands. Are long and tapered
75
Whay are water conducting cells of the xylem like?
2 types- tracheids and vessel elements Both are tubular, elongated cells that are dead at functional maturity. The cells walls are left behind forming a nonliving tube water can flow through. Secondary walls have pits where only a primary wall is visible where water can migrate laterally. Walls are hardened with lignin Tracheids: Found in the xylem of all vascular plants. Long, thin cells with tapered ends. Vessel elements: Found in most angiosperms, some gymnosperms and a few seedless vascular plants. These cels are wider, shorter, thinner walled and less tapered than tracheids. They are aligned end to end, forming vessels. The ends of these have plates that enable water to flow freely
76
What are sugar conducting cells of the phloem like?
Alive at functional maturity. Lack a nucleus, ribosomes, distinct vacuole and cytoskeletal elements, allow nutrients to pass through more easily. In seedless vascular plants: sugars and other organic nutrients are transported through long, narrow sieve cells In angiosperms: Nutrients are transported through sieve tubes, long chains of cells called sieve tube elements or sieve tube members
77
What are sieve plates?
The end walls between sieve tube elements in sugar conducting cells. They have pores that facilitate the flow of fluid from cell to cell along the sieve tube
78
What is a companion cell?
A nonconducting cell alongside each sieve tube element, connected to the sieve tube element by multiple plasmodesmata. Nucleus and ribosomes of companion cells serve sieve tube elements as well as well as helping load sugars into sieve tube elements
79
What is indeterminate growth?
Growth occurring throughout an organisms life, not limiting to a stage of life
80
What are meristems?
Cells that make plants capable of indeterminate by dividing when certain conditions permit leading to new cells that can elongate
81
What are the two main types of meristems?
Apical meristem: Located at tips of roots and shoots and axillary buds of shoots. They provide additional cells that enable growth in length(primary growth). Allows roots to extend through the soil and shoots to grow and absorb light Lateral meristem: Causes growth in thickness(secondary growth), called vascular or cork cambium. These cylinders of cells divide along the length of roots and stems.
82
How do wood and non-wood plants grow differently
Nonwood: Primary growth produces all or almost all of the plant body Wood: Also grow in circumference in parts of the stems and roots that no longer grow in length
83
What are the vascular and cork cambium?
Vascular: Adds layers of vascular tissue called secondary xylem(wood) and secondary phloem Cork: Replaces the epidermis with a stronger, thicker periderm
84
What determines the fate of a derivative meristem cell?
Its final position in the developing organ-cell to cell communication
85
How are vegetative and reproductive growth different? What makes plants switch between these?
Vegetative: Produce leaves, stems and roots. Inderminate Reproductive: Determinate. Production of flowers, seeds and fruits Plants switch between these due to environmental cues: day length, internal signals and hormones. Shoot apical meristem growth is redirected
86
What do growth of roots and growth of shoots have in common?
They are derived from the apical meristem
87
What are the stages of growing root cells? Where does this take place?
This take place behind the root cap at the tip of the root, where 3 zones of cells in different stages of primary growth are found 1. Zone of cell division: Includes root apical meristem and its derivatives. New root and root cap cells are produced here 2. Zone of elongation: Most growth occurs here as root cells elongate, pushing the tip farther into the soil. The root apical meristem adds younger cells to the end of this zone. Cells in this zone start to specialize 3. Zone of differentiation/maturation: Differentiation is complete and cells get their distinct cell types
88
How are the xylem and phloem different in monocots and eudicots?
Eudicot: Xylem has a star like appearance in cross section, and the phloem occupies the indentations between the arms of the xylem “star” Monocot: Vascular tissue consists of a core of undifferentiated parenchyma cells surrounded by a ring of alternating and differentiated xylem and phloem tissues
89
Describe the ground tissue of roots.
Consists mostly of parenchyma cells, found in the cortex between the vascular cylinder and epidermis
90
What is the endodermis?
The innermost layer of the cortex. It is one cell thick and forms the boundary with the vascular cylinder. It is a selective barrier that regulates passage of substances from soil to vascular cylinder
91
What is the pericycle?
The source of lateral roots. It is the outermost layer in the vascular cylinder, adjacent to and just inside the edodermis.
92
What is leaf primordia?
Projections shaped like a cow’s horn that emerge along the sides of a shoot apical meristem, where leaves develop
93
What is apical dominance?
Inhibition of an axillary bud by an active apical bud
94
What causes branching?
The activation of axillary buds(being distanced from apical buds)
95
What are intercalary meristems?
Areas at the bases of stems and leaves that experiences meristematic activity, allowing a plant to recover from damage quickly
96
What is the mesophyll?
A region in the ground tissue of a leaf that is sandwiched between the upper and lower epidermal layers, consisting mainly of parenchyma cells specialized for photosynthesis
97
How are vascular and ground tissues different in monocot and eudocot stems?
In eudicots, vascular tissues are arranged in a ring. The xylem in each vascular bundle are adjacent to the pith and the phloem in adjacent to the cortex. In monocots, vascular bundles are scattered throughout the ground tissue rather than forming a ring
98
How are stem tissues of monocots and eudicots similar?
Ground tissue consists mostly of parenchyma cells
99
In what types of plants does secondary growth commonly occur and vice versa?
It occurs in all gymnosperms and many eudicot species(woody plants). It is rare in monocots
100
Where does secondary growth occur?
The vascular and cork cambium in the stems of roots of woody plants, rarely the leaves
101
Where is the vascular cambium located in woody stems and roots?
Stem: Outside the pith and primaru xylem Root: Exterior of primary xylem and interior of primary phloem and pericycle
102
What are the different orientations of functions of initials produced by the vascular cambium?
Long axis parallel to the stem/root axis: Produce cells Long axis perpendicular: Aka vascular ray, shorter, parenchyma cells that connect the secondary xylem and phloem and move water and nutrients between the two, store carbs, and aid in wound repair
103
What are lenticels?
Horizontal slits dotting the periderm that allow living cells inside a woody stem/root to exchange gases with the air outside

AP Biology Mr. Maiorana (16 decks)

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