Week 2

Question 1

What are the 2 types of seeded plants?

Answer 1

Gymnosperms
Angiosperms

Question 2

What are the 2 types of Angiosperms?

Answer 2

Monocotyledonous
Dicotyledonous

Question 3

What are the features of Gymnosperms?

Answer 3

‘Naked’ seeds e.g conifers
phylum - Pinophyta

Question 4

What are the features of Angiosperms?

Answer 4

‘Vessel’ seeds e.g flowering plants
phylum - Magnoliophyta

Question 5

What are the classification of Monocotyledonous?

Answer 5

Embryo with single cotyledon
Class Liliosida e.g Gramineae, Poacaeae, embryo

Question 6

What are the classification of Dicotyledonous?

Answer 6

Embryo with two cotyledons
Class - Magnoliopsida

Question 7

What are the key features of monocots?

Answer 7

One leaf
Parallel venations
Scattered bascular bundles
Flowers in multiples of 3
No true secondary growth

Question 8

What are the key features of dicots?

Answer 8

Two seeded leaves
Reticulate venation
Vascular bundles in a ring
Flower parts not in multiples of 3
True secondary growth

Question 9

When did dicots split off from monocots?

Answer 9

Around 150 - 200 MYA

Question 10

When did Charles Darwin do his experiments on phototropism?

Answer 10

1880

Question 11

What 3 different shoots did Darwin experiment on?

Answer 11

Used a light source on:
Intact seedling
Tip of coleoptile excised
Opaque cap on tip

Question 12

What were the results of Darwins experiements?

Answer 12

Intact seedling moved towards light
Niether the shoot with the tip covered and cut off moved towards the light

Question 13

When were the follow up experiments by Boysen-Jensen underwent?

Answer 13

1913

Question 14

What were the 3 experiements that Boysen-Jensen did?

Answer 14

Shoot had mica sheet inserted into the dark side
Shoot has mica sheet inserted into the light side
Shoot were tip was removed then glued back on the celeoptile stump using gelatin

Question 15

What were the results of the experiments done by Boysen-Jensen?

Answer 15

Shoot with the mica sheet inserted into dark side didnt bend towards the light
Shoot with the mica sheet inserted into light side bent towards the light
Shoot where the tip was removed then reattached bent towards the light

Question 16

What makes a good model organism?

Answer 16

Comparatively easy to study (things like rapid life cycle)
Findings can be broadly applied
Knowledge and resources can be shared

Question 17

What plant species make good model organisms?

Answer 17

Marchantia polymorpha (liverwort)
Physcomitrella patens (a moss)
Oryza sativa (Rice)
Triticum aestivum (Wheat)
Solanum lycopersicum (Tomato)

Question 18

What plant species are used to characterise the cellular basis of important traits?

Answer 18

Arabidopsis thaliana (Mouse ear cress)
Oryza sativa
Medicago truncatula (a legume)

Question 19

Why is Arabidopsis thaliana a good model organism?

Answer 19

Fully sequenced (first plant) small genome - 5 chromosomes, ~25,000 genes
High density of genes
Extensive natural selection
Short lifecycle
Widely avaliabily of knowledge
Easy to genetically modify

Question 20

How would you generate mutants for genetic analysis?

Answer 20

Mutate a seed using chemicals
Grow seeds
Self fertilise seeds to produce M1 generation seeds
Seeds grown into M2 generation, the mutant sector should produce a ratio of 1:2:1 of seeds 2 wildtypes: seeds with 1 wildtype and 1 mutation: 1 with 2 mutation genes

Question 21

What the overview of Arabidopsis thaliana basic biology and phylogeny?

Answer 21

Apart of Brassicaceae
Dicot
Both summer annual and winter annual forms depending on conditions
Is not outcrosser - self pollinates, populations stay isogenic
Diploid

Question 22

What are the growth phases of Arabidopsis thaliana?

Answer 22

Two growth phrases:
Vegetative
Reproductive phrase

Question 23

What happens in the vegetative phrase in Arabidopsis thaliana?

Answer 23

Vegetative growth is when the plant grows a small rosette of leaves to phototsynthesise

Question 24

What happens in the reproductive phrase in Arabidopsis thaliana?

Answer 24

The plant produces inflorescence - small white flowers
Seeds form in pods called siliques

Question 25

What happens to Arabidopsis thaliana during periods of short day conditions?

Answer 25

The plant suppreses flowering
Plants grow larger rosettes

Question 26

What happens to Arabidopsis thaliana during periods of long day conditions?

Answer 26

The plant grows flowers
Plants have smaller rosettes

Question 27

How long is the complete life cycle of Arabidopsis thaliana?

Answer 27

Depending on conditions can be done in 6-8 weeks

Question 28

Why are Arabidopsis thaliana useful for experiments?

Answer 28

Very easy to grow on petri dish, in growth chambers
This allows for control with light and temperature
Isogenic genetics allows for easy reproducibility of results
Easy to genetically modify

Question 29

How would you genetically modify Arabidopsis thaliana?

Answer 29

Grow until it flowers
Dip flowers into a culture of Agrobacterium containing gene construct of choice
Collect the seed

Question 30

What two research projects about Arabidopsis thaliana allow for improvement of crops?

Answer 30

Research into circadian clock in Arabidopsis thaliana found gene PRR7 which turns out to be the difference spring and winter wheat
Epigenetics modifications of histones in Arabidopsis thaliana leads to flowering after winter which is the same process in the oilseed rape showing how crops will respond to climate chage

Question 31

What is pangenomics?

Answer 31

The pangenomics is a set of genomes that capture the natural variation in the species

Question 32

What other Arabidopsis that are important to research?

Answer 32

Arabidopsis lyrata (diploid)
Arabidopsis halleri (diploid)
Arabidopsis arenosa (tetraploid)
Arabidopsis kamchatika (tetraploid)