Chedy - theme 1

Question 1

Known # of animal species on earth:

Answer 1

MORE THAN ONE MILLION!!!!

Question 2

Define: heterotroph

Answer 2

An organism that cannot fix carbon to synthesize essential molecules from inorganic sources

Question 3

Classes of predators:

Answer 3

Carnivores, herbivores, omnivores, parasites, detrivores/saprophages

Question 4

Detrivores/saprophages:

Answer 4

Predators that consume dead organic matter

Question 5

Zygote cleavage:

Answer 5

Undergoes rapid division without significant growth; when it gets to 16 cells, it becomes a morula; after 7 divisions, it becomes a blastula

Question 6

Blastulation:

Answer 6

Cells inside the zona pellucida differentiate into trophoblasts (outside) and embryoblasts (inside).
The embryoblasts compact further and gather at one side of the cell (inner cell mass), creating a cavity called the blastocoel. At this stage, the cell is called a blastocyst. The zona pellucida breaks down.
The embryoblast forms a cavity called the amniotic cavity. The embryoblast differentiates into epiblasts (inside) and hypoblasts (outside).

Question 7

Gastrulation:

Answer 7

Primitive streak forms on the epiblast part of the bilaminar disc (the plane of the epiblasts and hypoblasts). As the cells of the epiblast migrate, a middle layer differentiates, making the entire structure a trilaminar disc. Germ layers!

Question 8

Gastrula:

Answer 8

The germ layers. Ecto, meso, endo.

Question 9

Ectoderm is the primary tissue of:

Answer 9

Skin and stuff attached to skin (hair nails feathers scales), nervous system, lens/retina/cornea, lining of mouth and anus, sweat/mammary glands, adrenal medulla, tooth enamel

Question 10

Mesoderm is the primary tissue of:

Answer 10

Skeletal system (muscles bones cartilage), circulatory system, internal reproductive organs, kidneys, outer wall of digestive tract

Question 11

Endoderm is the primary tissue of:

Answer 11

Lining of digestive tract, liver, pancreas, lining of respiratory tract, thyroid gland, lining of urethra, urinary bladder

Question 12

Different tissue types and their roles:

Answer 12

Epithelial: protection, secretion, absorption
Connective: structural support
Muscle: movement
Nervous: communication, coordination, control

Question 13

Define: organ

Answer 13

A body structure that integrates different tissues

Question 14

Diploblasts vs triploblasts:

Answer 14

Gastrulates into two germ layers (ecto and endo) instead of three. Instead of a mesoderm, there is a middle non-living layer. Seen in simple organisms like jellyfish, corals, hydra.

Question 15

Types of asexual reproduction:

Answer 15

Fission, budding, fragmentation, parthenogenesis (embryos form without fertilization)

Question 16

Origin of animalia:

Answer 16

Protista, 4.6 billion years ago.

Question 17

Choanoflagellates:

Answer 17

Protozoa similar to modern colonial flagellated species. Some specialization. Last unicellular ancestor of animals, closest living relative of animals.

Question 18

Sponges:

Answer 18

Suborder parazoa, phylum porifera. The only animal without neurons. Asymmetric; specialization. Basically no internal systems. Digestion is intracellular through phagocytosis. Express cell adhesion molecules (CAM).

Question 19

Eumetazoans:

Answer 19

Derived from sponges. Multicellular organism with differentiated tissues and embryonic development. Had cell contact, cell communication, and ECS (extracellular space).

Question 20

CAM:

Answer 20

Cell adhesion molecules. Involved in recognition, binding, and communication with other cells or the ECM. Include: adhesive glycoproteins, collagens, cell membrane-associated enzymes (Na-K ATPase, tyrosine kinase).

Question 21

Anchoring junctions:

Answer 21

Desmosomes, gap junctions, tight junctions.

Question 22

Desmosomes:

Answer 22

20nm. Spot-rivets the plasma membranes of interacting cells. Homophilic binding of cadherins.

Question 23

Tight junctions:

Answer 23

*** idk they have kiss sites, which is cute

Question 24

Gap junctions:

Answer 24

Impermeable. Join lateral edges of epithelial cells near their luminal borders. Associate with intracellular proteins of the cytoskeleton.
*** might be the description for tight…….

Allows transmission of action potentials in neurons.

Question 25

Blood-brain barrier:

Answer 25

Separates blood from the brain’s extracellular fluid. Consists of tight junctions around the capillaries. Regulates restriction.

Question 26

Collagen:

Answer 26

ECM protein essential for formation of all tissues. First produced by pinacocytes (type of sponge). Main structural protein in ECspace. 25-35% of animal proteins. Found in fibrous tissues.

Question 27

ECM:

Answer 27

Includes interstitial matrix, which serves as a compression buffer against stress. Main component of cartilage and bone.

Question 28

Calcification:

Answer 28

Collagen and elastic glycoproteins may be calcified to form structures like shells, bones, spicules. Dynamic - cells can go between calcified and decalcified. May be affected by osteoporosis.

Question 29

Membrane-associated proteins: ATPases

Answer 29

3 Na out / 2 K in, against concentration gradient. An electrogenic active enzyme pump.

Question 30

Membrane-associated proteins: tyrosine kinases

Answer 30

Phosphorylator: transfers a phosphate group from ATP to a tyrosine or serine in a protein. For signal transduction and activity regulation.

Question 31

Animal body plans:

Answer 31

35 different kinds.

Question 32

Evolution of nervous system:

Answer 32

The first evidence of NS appeared in diploblastic organisms (ctenophora and cnidaria).

Question 33

Jellyfish:

Answer 33

Two germ layers, distinct tissues, nerve net, digestive chamber with one opening.

Question 34

Nerve nets:

Answer 34

Simplest nervous system. Radially symmetrical. Neurons embedded in epithelium between epidermis and midlayer.

Question 35

Ganglia:

Answer 35

Nerve cell bodies with localized interconnections. Small brain consisting of two ganglia at anterior end (in flatworms). Eyespots! First evidence of localization of cells!!!

Question 36

Bits of the ganglial system:

Answer 36

Ocelli - simple eye structure.

Statocysts - fluid-filled sacs that help indicate position.

Question 37

Ganglia as pacemaker:

Answer 37

True jellies (scyphomedusae) have excitable cells that fire spontaneously, creating action potentials that drive swimming by continually signalling contraction.

Question 38

Bidirectional chemical synapses:

Answer 38

Neurons can transmit in either direction! Characteristic of ganglia in medusae.

Question 39

Nerve nets in organisms other than cnidarians:

Answer 39

Each phylum has diffuse nerve nets left over from evolution. In vertebrates, it’s a nerve plexus, a network of nerve cells in the intestinal wall. Propels food along the intestine.

Question 40

Phylum bilateria:

Answer 40

Triploblasts. Left and right sides are mirror images, dorsal and ventral sides are not identical, anterior and posterior ends are not identical. Specialized head with feeding and sensory organs. Digestive chamber with two openings. First true CNS.
Example: think of a lobster.

Question 41

Bilateria and CNS:

Answer 41

Segmented animals have one ganglion per segment. Platyhelminthes are the beginning of the true CNS - longitudinal nerve cords that coordinate nervous activity.

Question 42

PNS:

Answer 42

Works in conjunction with CNS. Peripheral connects the CNS to the rest of the body.

Question 43

Cephalization:

Answer 43

Evolutionary trend towards enlarged head because bilateria tend to move forward. Enlarged ganglia is organized into lobes. Sensory information is gathered in the head , allowing for more complex processing functions (images, learning, memory, self-awareness).

Question 44

Evolution of bilateria:

Answer 44

Correlated with ability to move through environment and cephalization. Advantageous because it allowed animals to encounter stimuli head-first (to predate or … be prey).

Question 45

Cephalopods:

Answer 45

Molluscs (squishy animals like octopuses, squid, clams, snails). Most cephalization of invertebrates. Neurons clustered into paired ganglia, organization into major nerves. Paired nerves connecting lobes with specific sensory organs. Some cephalopods can also control chromatophores.

Question 46

Arthropoda: describe the phylum

Answer 46

Segmented invertebrates with with exoskeletons. Includes insects, arachnids, and crustaceans. Cuticles and limbs composed of alpha-chitin. (Crustaceans’ cuticles also contain calcium carbonate.) Exoskeleton restricts growth, so it has to be moulted periodically.

Question 47

Arthropoda: nervous system

Answer 47

Brain consisting of dorsal and ventral ganglia and major sensory structures. Enlarged ganglion in each segment. Ganglia fuse into large structures that function as secondary control centres.

Question 48

Chordata:

Answer 48

Stiff rod through the vertebral column with nervous tissue above (spinal cord) and gastrointestinal tract below (two openings).

Question 49

Myelin:

Answer 49

Fatty white insulator on neural axons. Present in NS of all vertebrates. Produced by Schwann cells and oligodendrocytes.

Question 50

The bits of the spinal column:

Answer 50

Cervical, thoracic, lumbar, sacrum, coccyx.

Question 51

Tetrapods:

Answer 51

Four-footed. Most common land vertebrate body plan. Some have been modified - birds, bats, cetaceans (whales/dolphins/etc). Front limbs became wings or fins.

Question 52

Evolutionary advantages of the pipe body plan:

Answer 52

Pipe plan - digestive system with two openings.

This body plan is essential to being a complex and free-moving organism. Common system from earthworms to humans.