Lecture 8

Question 1

Is the stamen the male of female reproductive parts

Answer 1

Male reproductive parts

Question 2

Is Carpel the male or female reproductive parts

Answer 2

Female reproductive parts

Question 3

Name the parts of the stamen

Answer 3

•Anther (Pollen,Sperm)
•Filament

Question 4

Name the parts of the carpel

Answer 4

•Stigma
•Style
•Ovary

Question 5

Write a short note on SEXUAL reproduction

Answer 5

•produces offspring by the fusion of egg and sperm
•resulting in offspring that are genetically different to the parents and each other

Question 6

Write a short note on ASEXUAL reproduction

Answer 6

•produces offspring without the fusion of egg and sperm

•the offspring are genetically identical to the parent plant and to each other (aka clones)

Question 7

What is CROSS pollination

Answer 7

pollen from one flower pollinates flowers on a different plant

Question 8

What percentage of cross pollination is BIOTIC

Answer 8

80%

Question 9

What percentage of cross pollination is ABIOTIC

Answer 9

20%

Question 10

Example of BIOTIC pollinators

Answer 10

•birds, bats and mammals

•but most biotic pollination is by insects (c.65%)

Question 11

Name the two modes of ABIOTIC pollination

Answer 11

•98% wind
•2% water

Question 12

Example of cross pollinated species

Answer 12

•maize
•rye
•carrot
•cauliflower
•onion

Question 13

What is SELF pollination

Answer 13

pollen from one flower pollinates the same flower or other flowers on the same plant

Question 14

Example of self pollinated species

Answer 14

•wheat
•rice
•barley
•mung bean
•cowpea

Question 15

What type of species is SELF pollination mostly seen in

Answer 15

short-lived annual species and plants that colonize new locations

Question 16

Name the most important pollinators

Answer 16

Bees

Question 17

What kind of characteristics are bees attracted to

Answer 17

•Bright colours
•Sweet fragrance

Question 18

What do honey bees feed on for food

Answer 18

•Nectar
•Pollen

Question 19

What kind of characteristics are moths attracted to

Answer 19

•Light coloured or dull flowers to be seen in low light
•sweetly fragrant flowers

Question 20

What kind of characteristics are bats attracted to

Answer 20

•Flowers that are light coloured or dull to be seen in low light
•flowers that smell musty

Question 21

What kind of characteristics are birds attracted to

Answer 21

•Flowers with bright red,orange,yellow flowers
•Flowers that have very little scent

Question 22

What is special about Soybeans(Glycine max)

Answer 22

•flowers open and remain receptive to insect cross pollination during the day.

•If this is not accomplished, the flowers self-pollinate as they are closing in the evening.

Question 23

What does sexual reproduction result in

Answer 23

Seeds

Question 24

Example of important crops grown from seed

Answer 24

• Grass, cereals (rice, wheat, maize, barley, oat, rye)
• Legumes (pea, bean, soybean, clover, mung bean, cowpea)
• Vegetables, fruits, flower seeds (for humans/animals) • Commercial crops e.g. sugarcane, oilseed

Question 25

If asexual reproduction doesn’t produce seeds how does reproduction occur

Answer 25

• Fragmentation (stolons, runners e.g. strawberry,kikuyu grass (Pennisetum clandestinum) • Tubers (potatoes,crocus corm,lily,dahlia) • Bulbs (onions, daffodils) • Cuttings (stem, leaf, root) • Grafting or budding (fruit trees, roses)

Question 26

What is Apomixis

Answer 26

Asexual reproduction that produces seeds without the fusion of egg and sperm i.e. it is clonal reproduction through seeds

Question 27

What are the two ways Apomixis can occur

Answer 27

• embryo arises from an unfertilized egg cell • embryo is formed directly from some part of egg cell

Question 28

Advantages of sexual reproduction

Answer 28

• Introduces variation • Adaptability to new environments • Adverse conditions less likely to affect everyone • Seed dispersal reduces competition • Dormant seeds can survive unfavourable conditions in soil

Question 29

Disadvantages of sexual reproduction

Answer 29

• Needs two parents • Fertilisation is random so harmful variations can occur • Flowers and seeds are energetically expensive • Can lead to extinction e.g. Encephalartos woodii (only males left but reproduces by basal offsets)

Question 30

Is sexual or asexual reproduction good in unstable environments

Answer 30

Sexual reproduction

Question 31

Advantages of asexual reproduction

Answer 31

• Only one parent needed • Rapid colonisation of favourable environments • Any part of plant can become a new plant • Reproduction is faster • No genetic variation can be an advantage in commercial horticulture

Question 32

Disadvantages of asexual reproduction

Answer 32

• No genetic variation so adverse conditions, pests and diseases are likely to affect all individuals • Cannot adapt • May be prone to extinction • No seeds so no dormancy mechanism • Overcrowding and competition for resources

Question 33

Is sexual or asexual reproduction good in stable environments

Answer 33

Asexual reproduction

Question 34

Name the oldest creosote bush in the Mojave desert

Answer 34

King Clone 11,700 years old Single colony of Larrea tridentata reaches up to 20 meters in diameter

Question 35

Is metabolic rate low or high during seed dormancy

Answer 35

Extremely low metabolic rate

Question 36

When does Germination occur seed dormancy

Answer 36

When seedling is likely to survive

Question 37

What happens to growth and development during seed dormancy

Answer 37

Both are suspended

Question 38

What is certified seed

Answer 38

Seed that is handled so as to satisfactorily maintain genetic identity and purity, and that has been approved and certified by the certifying agency

Question 39

What does certification involve

Answer 39

field inspection, pre- and post-control tests, and seed quality tests.

Question 40

What do football pitches use

Answer 40

Best quality certified seed

Question 41

Seed for golf greens must be certified free of what

Answer 41

Annual meadow grass

Question 42

Principles of seed storage

Answer 42

• Seed storage conditions should be dry and cool • Effective storage pest control • Proper sanitation in seed stores • Before placing seeds into storage they should be dried to required moisture limits • Store high quality seed only i.e. well-cleaned and treated, as well as of high germination and vigour

Question 43

What does Seed germination begin with

Answer 43

Imbibition

Question 44

Write a short note on the stages of seed germination after Imbibition

Answer 44

• Serotiny: fire required to release seeds from plant • Stratification: cold period to break dormancy • Scarification: seed coat damage • Acid digestion: seed coat breakdown • Substantial rainfall: desert plants • Dark (most seeds) • Light (lettuce, celery)

Question 45

How long are most seeds viable for after seed germination

Answer 45

1-2 yeaes

Question 46

Who proposed descent with modification

Answer 46

Darwin in 1859

Question 47

What is descent with modification

Answer 47

• Natural adjustment of genetic make-up through generations over time • Based on adaptations that enhance survival and reproduction in specific environments • Individuals with certain inherited traits leave more offspring • Over time, these traits become more prevalent in the population

Question 48

What is Modern maize derived from

Answer 48

Teosinte

Question 49

Why would modern maize become extinct without human propagation

Answer 49

Modern maize cannot spread its seeds

Question 50

What is micropropagation also know

Answer 50

In vitro tissue culture

Question 51

What does genetic engineering involve

Answer 51

the creation of recombinant DNA, which is inserted into the genetic material of a cell or virus