embryo growth and development

Question 1

what are the first two things to emerge

Answer 1

radicle(first) and the plumule

Question 2

what makes up the embryo of a seed

Answer 2

the plumule and radicle

Question 3

what does the radicle grow into

Answer 3

the root system

Question 4

what is the plumule protected by

Answer 4

a structure called the coleoptile

Question 5

what is epigeal germination

Answer 5

above ground germination

Question 6

what is hypogeal germination

Answer 6

below ground germination

Question 7

what is the epicotyl

Answer 7

the stem above the cotyledons

Question 8

in hypogeal germination what does the epicotyl do

Answer 8

pulls the plumule out of the soil

Question 9

what conditions promote good germination

Answer 9

• seed viability
• seedling depth
• seedling vigour (do seeds have enough strength to grow to a healthy plant)

Question 10

generally, it’s safer to plant ___ seeds deeper then ____

Answer 10

larger, smaller

Question 11

what is successful germination dependent on

Answer 11

weather or not the seedling can become self-sustaining before the food in the seed is used up

Question 12

what does dormancy in seeds mean

Answer 12

seeds are viable but fail to germinate when conditions are favorable
a period in which a plant does not grow, awaiting necessary environmental conditions such as temperature, moisture, nutrient availability

Question 13

what are some benefits of dormancy

Answer 13

survival mechanism which prevents germination until favorable times

also allows for staggered germination

Question 14

what are the two types of dormancy

Answer 14

exogenous
endogenous
combination of both is called double dormancy

Question 15

what is exogenous dormancy

Answer 15

dormancy due to physical restraints. germination is prevented due to physical, mechanical, or seed coat dormancy. the hard seed coat prevents the entry of oxygen or water for germination to begin

Question 16

how is exogenous dormancy overcome

Answer 16

weathering of the seed or passing through an animal’s digestive tract or microorganism action is needed

scarification

heat treatment

deprivation of oxygen

Question 17

what is scarification

Answer 17

is mechanical scratching or rupturing of the seed coat to enables germination

Question 18

what seed family often needs to be scarified

Answer 18

the legume family as often have very hard seeds

Question 19

what are some other terms for endogenous dormancy

Answer 19

embryonic or physiological dormancy

Question 20

what are some strategies used to overcome endogenous dormancy

Answer 20

stratification,

chemical block

Question 21

what is stratification

Answer 21

many seeds won’t germinate until they have been exposed to (weeks-months) to cool temperatures with oxygen and moisture present

Question 22

how is stratification used as a survival mechanism

Answer 22

prevents seeds from being germinated in the fall when they may be killed over the winter. it forces them to wait till spring when conditions are good

Question 23

what is chemical blocks in germination

Answer 23

some seeds contain chemicals that prevent germination.

chemicals may include salt, cyanide, or ammonia releasing compounds

Question 24

how are chemical blocks overcome

Answer 24

with adequate moisture, the chemicals will leach out of the seed and allow for germination.
this will ensure that seeds will begin germination when there is an adequate amount of moisture to support growing

Question 25

do our cultivated crops still have dormancy

Answer 25

no many of our crops have lost their dormancy or been selected against them

Question 26

why is no dormancy in cultivated crops beneficial

Answer 26

dormancy can interfere with the production of the crop or the further use of the seed. it allows for rapid even germination.

Question 27

what is viability in a seed

Answer 27

the ability to germanate if suitable conditions are present

Question 28

what is longevity

Answer 28

the length of time a seed can remain dormant and still be viable

Question 29

what factors depends on the longevity

Answer 29

plant species
growing conditions
storage conditions

Question 30

what is the longevity of wheat

Answer 30

6 to 32 years

Question 31

what is the longevity of barley

Answer 31

2 to 10 years

Question 32

what is the longevity of oats

Answer 32

6 to 29 years

Question 33

what is the longevity of wild mustard

Answer 33

up to 60 years

Question 34

what is the longevity of vegetable seeds

Answer 34

1 to 5 years

Question 35

what are some factors the contribute to a lower longevity

Answer 35

immature sees
low food reserves in food
diseased
physically damaged