Bio Final Exam

What are gynosperms?

plants without flowers

What is the difference between plants and algae? What’s the advantage they have?

Plants are on land, algae is underwater. It is easier for plants to get direct access to sunlight since 50% of sunlight gets absorbed by water

What are the challenges for living on land?

• lack of water

• no protection against extreme dryness

What are the functions of leaves?

Getting CO2 and Sunlight above ground

What are the functions of roots?

get water and minerals from ground, exchanges O2 for CO2 from the ground

What is the function of the vascular system?

transport water and nutrients throughout body

What is pollen?

male gametophyte packaged and dispersed as sperm through the air/animals

What are seeds?

developing embryo with food source and protective layer

What were the steps that lead to plants evolving to be on land? (4)

1. Mosses - have basic traits to live on land

2. Ferns - have traits to combat gravity

3. Gymnosperms - have traits to reproduce without water

4. Angiosperms - take full advantage of their environment

How do mosses protect against dryness?

Covering spores with sporopollenin

cuticles (waxy protective layer)

stomata closing to preserve water

What kind of life cycle do mosses go through?

alterations of generations

What are the steps of the moss life cycle

1. Spores grow into protonemata

2. Protonemata produces buds that grow into m and f gametophyte

3. Sperm from M.G swims to egg → produce zygote

4. Zygote is nurtured by F.G and grows into Sporophyte

5. Sporophyte produces spores with F.G attached

What is the advantage of plants being tall?

Better exposure to light and better chance to disperse spores farther

What is the function of roots?

Anchor plant to the ground and absorb water and nutrients

What is the function of stem

Connect roots with the rest of the plant and make the plant taller

What is the function of the leaves?

absorbing light for photosynthesis

What is the function of the vascular system?

Transportation of nutrients throughout the plants

What is the function of xylem?

Transport water and minerals

What is sporophyll?

Leaves of plants that produce spores

What is Sporangium?

Tissue on the sporophyll which do the spore producing

What is the life cycle of a fern?

1. Spores grow into bisexual gametophyte

2. Gametophyte produces ova-producing and egg-producing organs

3. the sperm from the organ swims to the egg from gametophyte and fertilizes

4. Zygote matures into independent sporophyte

What are cones?

sporophylls produced by gynosperms (can be male or female

What are the male cones? What do they end up as?

microsphorophylls (2n) which have microsporangium (2n) which produce microspores (2n)

• microspores grow up into male gametophytes (n) and produce pollen (n)

What are the female cones? What do they produce?

megasporophylls which contain megasporangium (2n) which produce megaspores (n)

• megaspores grow up into female gametophyte and produce eggs (n)

What does the ovule contain?

Contains integument + megaspore + megasporangium

How does the ovule develop into a seed?

develops after pollination (which contains the sperm) and fertilizes the ovule → produce zygote → turns into embryo + tissues from the F.G becomes its food supply and the integument becomes the covering

What are the major differences between gynosperm and angiosperm?

Environment

• G is exposed but A is in ovary

Pollination

• G has ovule develop into seed. A also develops into seed but ovary develops into fruit

What is the advantage of angiosperms?

• take advantage of their environment, they bear fruit and flowers and lets animals disperse their pollen

  ex. dandelions

What does the sepal of a flower do?

encloses the flower before it opens

What is the stamen?

male reproductive organ which contains microsporangium to produce pollen

What is the Carpel?

female reproductive organ which contains stigma for the pollen to attach to and ovules

What is the life cycle of flowers?

1. megasporangium produces megaspores which develop into F.G and then egg

2. The Anther produces microspores which develop into M.G and then pollen

3. Pollen attaches to the sitgma and develops pollen tube

4. pollen tube reaches ovule and fetilizes

5. Zygote is produced and then developed into embryo (seed)

6. Seed is dispersed and matured into sporophyte

How do fruits benefit the seed?

Protects and helps with dispersal.

How do fruits help with dispersal?

• some get eaten by animals and the undigested seed is released as feces

• some are specialized to be dispersed by the wind

What are the four types of fruit?

1. simple

2. aggregate

3. multiple

4. accessory

What are simple fruit?

dervied from single carpel or multiple infused carpel

What is aggregrate fruit?

dervied from flower with individual carpels making up a fruitlet

What is multiple fruit?

derived from multiple flowers clustered together. Different ovaries get fused into one fruit

What is accessory fruit?

The parts of the flower develop into different parts of percieved fruit

Explain how an apple is an accessory fruit?

the “core” is the fruit which is developed from the ovule

The edible part around the core is the tissue from the ovule to protect the seeds

How do plants obtain nitrogenous compounds?

absorbed by roots

How are nitrogenous compounds found in the soil?

Nitrogen gas in the athmosphere get fixed by (some free living) nitrogen fixing bacteria to NH3

How does the Rhizobium sp. work?

coexists within specalized root nodules of the host plant which is welcomed by the growing plant. It then fixes nitrogen in an anaerobic environment provided by the nodule which provides nitrogen for the plant

What is crop rotation?

Planting nitrogen-absorbing crops to help sustain the nutrient supply of the field

What is the three field crop rotation?

A three field system

1. Wheat - depletes nitrogen

2. Beans - absorbs nitrogen

3. No crops but animals feces can be used as nutrients

What’s the difference between animals with plants + fungi

1. no cell wall - structural support is from collagen, made outside of the cell

2. life cycle is dependent on diploid adult phase

How does the animal embryo develop?

1. cell divides in sections by cleavege

2. After multiple divisions the zygote becomes a blastula which has a thin layer covering a hollow space (blastoceol)

3. Blastula goes through gastrulation → gastrula → two different surfaces

What is gastrulation?

when one end of the bastrula encloses, making it into a gastrula

What is the archenteron?

hollow area inside the gastrula

What is the blastospore?

the opening of the archeteron

What is the ectoderm?

the surface facing the environment

What is the endoderm?

the surface facing the internal space

What happens to the gastrula after the first opening?

A second opening occurs to complete digestive tract

• one opening becomes the mouth, the other the anus

What is mesoderm?

third layer of cells developing between endoderm and ectroderm while second opening opens

What is the beginning of cell differentiation?

gastrulation → development of the digestive tract

What is embryo development in identical twins?

• the embryo is physically split into two, each developing an independent fetus

What is embryo development in fraternal twins?

• two eggs are fertilizied together

What are the three types of body plan in an animal?

• radial symmetry

• bilateral symmetry

• no symmetry

What is radial symmetry?

• The body is arranged around a single axis that passes through the center of the body from the top

• The whole body interacts with the environment from equal sides

• ex. jellyfish, sea anemone

What is bilateral symmetry?

• The body being arranged around two axis: Head-Tail & Dorsal-Ventral

What is an example of an animal with no symmetry?

sponges. they can grow into many assymetrical shapes

What is the animal kingdom?

• metazoa

• monophyletic group derived from single common ancestor

What were the first group of animals to diverge from the rest?

sponges (lack nerves, tissues, and muscles)

What is a Eumetazoa?

all animals that are not sponges

What are the two groups of Eumetazoa?

1. basal Eumetazoa - radial symmetry (jellyfish)

2. everyone else

What are the three major bilateral clades?

1. Lophotrocozoa (snails, worms)

2. Ecdysozoa (crabs, butterflies)

3. Deuterostomia (starfish, human)

What are the function of rhizoids

to anchor the plant to the ground but don’t transport water

Explain evidence on how mosses are related to algae

• the protonema found in the life cycle of mosses looks similar to charophyte algae

• use anti-dissection methods

• use sporopollenin

Explain how sponges are the sister group to Eumetazoa. What are sponges made out of?

• suspension feeders which draws in water from side pores and out from central cavity filters out food particles in water

• two cell layers filled by meshophyll

• no highly differentiated tissues

Explain how choanoflagellate are sister group protists of animals

• closest protists to animals

• molecular analysis + fossil evidence

• Their cells look very similar to the collar cells of sponges

Explain how the choanoflagellate S. rosetta are sister group of animals

• they have proteins to stick onto cells → forms a colony

• differentiate into various cell types depending on social cues (colonial, individual, etc)

What are the traits that majority of animals dont have due to being invertebreates?

backbone

limbs with digits

hinged jaw

What group are not invertebrates?

some chordatas

What two traits do all members of Eumetazoa have?

digestive tract and differentiated tissues

Why is it difficult to study ancestry of invertebrates through morphology?

A huge mix of homologous and analogous traits got lost and developed throughout the many lineages. Their phylogeny is based on molecular evidence

What are animals with bilateral symmetry that are exclusively invertebrates? Which one has some vertebreates

Lophotrochozoan and Ecdysozoa

Deuterostomia

What traits do Lophotrochozoan have and what are they used for?

1. Lophophore - used for feeding

2. Trochophore Larva: developmental stage

What does Ecdysozoa have and what is it used for?

exoskeleton for support and protection.

shedding of exoskeleton → molting

What are molluscs?

mostly marine terrestrial species

• many members have a hard shell made up of calcium carbonate

What is the mantle cavity?

open space that contains gills, anus, execratory system, etc

What are bivalves?

aquatic suspension feeders (oysters) → two shells connected by a hinge

What is the function of gills?

feeding and gas exchange

trap food as water passes through gills

What are cephalopods?

aquatic hunters (octopus)

What are ectdysozoans?

• exoskeleton made up of cuticle and moults

• more species than all other groups combined

What are nematodes? What is an example?

worms that are found in many habitats and are free living or parasitic

• C. elegans

What does the arthopod body contain?

• segments body with joint appendages

• compound eyes

• body coated by cuticle

What kind of relationship do plants and insects have and what do they do?

• mutalistic

• insects pollinate flowers and plants provide nutrients

What is incomplete metamorphesis?

Gradual growth of larva into adult form through multiple moulting

What is complete metamorphosis

Stepwise larva growth into adult via pupal stage

larval tissue is completely broken down

What are the two major classes of Deuterostomes

echinoderms and chordates

What are the four derived traits for chordata?

1. notochord

2. dorsal hollow nerve chord

3. pharyngeal slits

4. post-anal tail

What is a notochord?

long flexible rod between nerve chord and digestive tract

What is the dorsal, hollow nerve chord?

nerve chord of the embryo that develops from neural plate into neural tube

What is the pharyngeal slits?

arches and grooves the form the outside of the pharynx in the embryo

What is the post-anal tail?

tail of chorodates that extends past the anus

non-chorodates extends to the whole body

What are lancelets?

invertebrates with all four traits

What are tunicates?

closer to vertebrates than lacelets

the larvae has all four chorodate traits

Explain how a human embryo looks like a typical Chordate

has all 4 derived features

notocord → vertebra

nerve cord → spinal chord and brain

phrayngal slits → face and neck tissues

post-anal tail → present in the embryo

Name the four major groups of plants and draw a cladogram to show their evolutionary relationships.

• Include their closest-relative algae as the basal group, and give evidence that place this algae as the closest relative to plants.

→ algae

→ moss

→ fern

→ gymnosperm

→ angiosperm

Describe the benefits and challenges of the terrestrial environment for a photosynthetic organism, as opposed to living in an aquatic environment

benefits: easier access to sunlight

challenges: risk of dissecation,