BIOS1101 Practical Exam

Darwinian demon

A hypothetical organism that maximises evolutionary fitness by having unlimited resources and no limitations on reproduction, survival, or lifespan.

Formula for identifying similarity between species (percentage)

no. same amino acids / total amino acids * 100

e.g. no. same amino acids = 23

total amino acids = 30

overall similarity = (23/30)*100 = 77%

what are coelomates? + phylum examples

Coelomates are animals that possess a true coelom, a fluid-filled body cavity completely lined by mesoderm. Examples include chordates, and annelids.

what are acoelomates? + phylum examples

Acoelomates are animals that lack a coelom, instead having a solid body without a fluid-filled cavity. Examples include Platyhelminthes.

what are pseudocoelomates? + phylum examples

Pseudocoelomates are animals that have a body cavity called a pseudocoel, which is not fully lined by mesoderm. Examples include Nematodes.

what is diploblasty?

having two tissue layers (endoderm and ectoderm)

what is triploblasty?

having three tissue layers (endoderm, mesoderm, ectoderm)

what evolutionary advantage can bilateral symmetry provide?

allows more direct and mobile movement

advantage of a coelom?

provides a space for organs in an organism

Phylum porifera:

1. are they symmetrical?

2. how many tissue layers (diploblast or triploblast)?

3. coelomate, acoelomate or pseudocoelomate?

4. do they have a skeleton?

5. are they segmented?

1. not symmetrical

2. zero tissue layers (neither)

3. acoelomate

4. yes - fibres of calcium carbonate, silica or spongin

5. not segmented

Phylum Cnidaria:

1. are they symmetrical?

2. how many tissue layers (diploblast or triploblast)?

3. coelomate, acoelomate or pseudocoelomate?

4. do they have a skeleton?

5. are they segmented?

1. yes - radial symmetry

2. two - endoderm and ectoderm (diploblast)

3. acoelomate

4. no skeleton

5. not segmented

Phylum Platyhelminthes:

1. are they symmetrical?

2. how many tissue layers (diploblast or triploblast)?

3. coelomate, acoelomate or pseudocoelomate?

4. do they have a skeleton?

5. are they segmented?

1. yes - bilaterally

2. three - endo, ecto, meso (triploblast)

3. acoelomate

4. no skeleton

5. no segmentation

Phylum nematoda:

1. are they symmetrical?

2. how many tissue layers (diploblast or triploblast)?

3. coelomate, acoelomate or pseudocoelomate?

4. do they have a skeleton?

5. are they segmented?

1. yes - bilaterally

2. three (triploblast)

3. pseudocoelomate

4. no skeleton

5. no segmentation

Phylum annelida:

1. are they symmetrical?

2. how many tissue layers (diploblast or triploblast)?

3. coelomate, acoelomate or pseudocoelomate?

4. do they have a skeleton?

5. are they segmented?

1. yes - bilaterally

2. three (triploblast)

3. coelomate

4. yes - hydroskeleton

5. yes

phylum arthropoda:

1. are they symmetrical?

2. how many tissue layers (diploblast or triploblast)?

3. coelomate, acoelomate or pseudocoelomate?

4. do they have a skeleton?

5. are they segmented?

1. yes, bilaterally

2. three (triploblast)

3. coelomate

4. yes - exoskeleton

5. yes

phylum mollusca:

1. are they symmetrical?

2. how many tissue layers (diploblast or triploblast)?

3. coelomate, acoelomate or pseudocoelomate?

4. do they have a skeleton?

5. are they segmented?

1. yes - bilaterally

2. three (triploblast)

3. coelomate

4. some have external (shells) e.g. snails — some have reduced internal (mantle) e.g. octopus

5. no segments - only chitons

3 common traits among all molluscs?

muscular foot, visceral mass (containing organs), and mantle (secretes shell)

phylum echinodermata:

1. are they symmetrical?

2. how many tissue layers (diploblast or triploblast)?

3. coelomate, acoelomate or pseudocoelomate?

4. do they have a skeleton?

5. are they segmented?

1. yes - radial

2. three (triploblast)

3. coelomate

4. yes - endo

5. not segmented

phylum chordata:

1. are they symmetrical?

2. how many tissue layers (diploblast or triploblast)?

3. coelomate, acoelomate or pseudocoelomate?

4. do they have a skeleton?

5. are they segmented?

1. yes - bilateral

2. three (triploblast)

3. coelomate

4. yes, internal - can be bony, or cartilaginous

5. kind of

name 3 types of mammals and what makes them unique

-marsupial - have a pouch

-placental - live birth

-monotreme - lay eggs

skeletal muscle tissue: location + what do they help with?

connect to the skeleton - help with voluntary muscle movements e.g. bending your arm

skeletal muscle tissue: how can you identify them?

-striations (need to contract and extend very fast)

-nuclei off to the side

cardiac muscle tissue: location + what do they help with?

in the heart - handles lots of pressure from blood being pumped by heart

cardiac muscle tissue: name 3 features of cardiac muscles

-striations

-intercalated discs

-branched out (to cover entire heart)

cardiac muscle tissue: 1 visual difference between vein and artery cross section?

-artery - thick wall, circular

-vein - thin wall, infinity shaped (wider on sides, thinner in middle)

smooth muscle tissue: function? + examples of location/function

responsible for involuntary muscle movement e.g. digestion (intestines), blood pressure regulation (veins, arteries)

smooth muscle tissue: why aren’t they striated?

no fast contractions occur where there are smooth mucles

epithelial tissue: where would you find simple squamous epithelium?

in smooth muscles - lungs, veins, arteries

epithelial tissue: describe the form of simple squamous epithelium + why this is useful

thin, once cell thick - allows for gas exchange

epithelial tissue: where would you find simple cuboidal epithelium?

intestines (but less so), glands, testes, ovaries

epithelial tissue: describe the form of simple cuboidal epithelium + why this is useful

cuboid - gaps in between each cell for excretion

epithelial tissue: where would you find simple columnar epithelium?

intestines, oviduct

epithelial tissue: describe the form of simple columnar epithelium + why this is useful

columnar - good for absorbtion

what is this? what is the line pointing to?

skeletal muscle tissue

what is this? what are the lines pointing to?

Lung tissue

what is this? what is the line pointing to?

striated muscle tissue

what is this? what are the lines pointing to? (name at least 3-4)

stomach

what is this? what epithelial cells are the lines pointing to?

stomach

what is this?

artery

what is this?

vein

what is this? what are the lines pointing to?

ovary

what is this?

testis

what is this?

cardiac muscle

what is this?

smooth muscle

what is this? what epithelial cells can you see?

oviduct - columnar

what is this?

small intestine

is this wood from an angiosperm or a gymnosperm? why?

angiosperm - because its porous (has vessels)

what are traits associated with plants in an aquatic environment?

-flagellated sperm

-simple diffusion for nutrient uptake

-rhizoids

what are traits associated with plants in a moist terrestrial environment?

-stomata

-rhizoids

-flagellated sperm

-photosynthetic gametophytes

-spores

what are traits associated with plants in a dry terrestrial environment?

-stomata

-woody tissue

-roots

-pollen

-seeds

-vascular tissue

-waxy cuticle

rhodophyte algae:

1. what colour?

2. are they plants?

3. depth found? (deepest, middle, shallowest)

1. red algae

2. not really?

3. deepest (~250m)

Phaeophyta:

1. what colour?

2. are they plants?

3. depth found? (deepest, middle, shallowest)

1. brown algae

2. technically protists

3. middle (~200m)

chlorophyta:

1. what colour?

2. are they plants?

3. depth found? (deepest, middle, shallowest)

1. green algae

2. most plant-like out of all three algae

3. shallowest (150m)

what is this? what are the missing words? what type of plant?

a gametophyte and sporophyte - bryophyte (moss)

what are the archegonia in bryophytes?

-egg-bearing organ with long neck

-extends beyond the venter

-capped at tip with cover cells

what are the antheridia in bryophytes?

-sperm-bearing organ with outer row of sterile (non-sperm forming) cells enclosing inner fertile cells, each of which becomes a sperm

describe the fertilisation process of bryophytes

• sperm from antheridium fertilises in archegonia

• sporophyte grows from female gametophyte

• spores released from mature capsule in sporophyte

• spores grow into filamentous protonema

• young gametophytes grow from protonema

what is this? what are the missing words? what type of plant?

sporophyte and gametophyte in a fern

describe the fertilisation process in ferns

• sperm use flagella to swim to archegonia (archegonia uses attractants to attract the sperm)

• zygote develops into sporophyte/gametophyte

• then into mature sporophyte

• then into sporangium that contains the pollen

describe the fertilisation process in gymnosperms

occurs in cone where the developed seed is exposed

what are the sporophyte and gametophytes in gymnosperms?

-sporophyte - the tree

-gametophyte (male) - pollen

-gametophyte (female) - within the ovule

what are the sporophyte and gametophytes in angiosperms?

-sporophyte - the flower

-gametophyte (male) - pollen

-gametophyte (female) - within the ovule

describe the fertilisation process in angiosperms

• once pollen grain reaches the stigma, it makes a pollen tube down the style to the ovary

• two sperm cells enter - one fuses to an egg cell (to make a zygote - 2n) and the other to 2 polar nuclei (to make an endosperm - 3n)

• embryonic development begins - the ovule becomes a seed

what are the 2 nuclei present in a mature pollen grain?

tube nucleus and generative nucleus

what is the role of synergid and antipodal cells in the development of an embryo?

-synergid - attracts the pollen tube through the micropyle (opening to the ovule)

-antipodal - unknown but may help develop the endosperm

simple fruit:

1. no. of carpels/ ovaries?

2. no. of flowers?

3. examples?

1. 1 carpel

2. 1 flower

3. blueberry, cherry, peaches, sunflower

aggregate fruit:

1. no. of carpels/ ovaries?

2. no. of flowers?

3. examples?

1. several

2. 1 flower

3. strawberry, raspberry

multiple fruit:

1. no. of carpels/ ovaries?

2. no. of flowers?

3. examples?

1. several

2. several flowers

3. pineapple, fig

what makes a fruit an accessory fruit? + examples

a fruit that is made from tissues separate from the carpel e.g. apples (made from hypanthium) and strawberries (made from receptacle)

what hormone is responsible for the ripening of the fruit?

ethylene

what environmental factors trigger germination?

water availability, oxygen, temperature, and light

what hormones are associated with seed dormancy and germination in plants?

-abscisic acid (ABA) - growth inhibitor and seed maturation

-gibberellin - growth promotion

which is the monocot and which is the eudicot stem cross section?

left - eudicot

right - monocot

if, when in presence of hydrogen peroxide, a stigma bubbles/fizzes, what does this mean?

it means the stigma is ready for fertilisaiton

name the 4 tropism’s plants use to survive in their environments and what each does

-phototropism - makes a plant grow towards light

-gravitropism (negative) - makes roots grow downward

-gravitropism (positive) - makes plants grow upward

-thigmotropism - makes plant wrap around nearby objects/plants for stability

-hydrotropism - helps roots grow in the direction of water

what plant hormone mediates gravitropism and phototropism? how does their reaction affect the plant?

auxin - they always fall in response to gravity. if they detect a change in light or orientation of the plant, they will perform cell elongation on the opposite side (e.g. will elongate cells on the underside of a plant in response to it falling)

which plant tissues are lignified?

sclerenchyma and xylem

why does the phloem have a companion cell

it accompanies the xylem and forms the vascular bundle

what forces pull water through xylem vessels?

capillary action (cohesion and adhesion), hydrostatic pressure, and diffusion pressure

how do vascular bundles provide support the stem of a plant?

lignified xylem keeps stem (and plant) upright

why is the palisade mesophyll tightly packed? why is the spongy mesophyll loosely packed?

-palisade mesophyll is tightly packed to maximise light absorption for photosynthesis

-spongy mesophyll is loosely packed to facilitate gas exchange