Final exam

Question 1

What is a plants phenotype made up of?

Answer 1

Genotype + Environment = Phenotype

Phenotype is the overall appearance of the plant.

Question 2

How do mitosis and meiosis differ in terms of resulting products and what type of development are they used for in a plant?

Answer 2

Mitosis is cell division of vegetative tissue.

Meiosis is cell division initiated from male and female gametes.

Question 3

What is a seed and what three things does a viable seed consist of?

Answer 3

A seed is a mature ovule containing an embryo that is usually the result of sexual fertilization.
Consists of: Embryo, food storage tissue, seed covering/seed coat

Question 4

What occurs during double fertilization?

Answer 4

One male gamete unites with a female gamete to form a zygote, while the other male gamete unites with 2 polar nuclei to produce the endosperm.

Question 5

What are two characteristics that can be used to distinguish a juvenile plant from an adult plant and for propagation why do we care which maturity the plant is?

Answer 5

Growth habit and leaf shape
It is important to know which stage of maturity the plant is in because some plants are easier to root in the juvenile stage. There may also be different requirements for propagation depending on what stage the plant is in.

Question 6

What is the difference between Orthodox and recalcitrant seed?

Answer 6

Orthodox seeds are those that tolerate maturation drying and survive at less than 10% moisture.
Recalcitrant seeds are those that are unable to withstand maturation drying. They must not dry below 30 to 50% moisture or they will lose viability.

Question 7

What are rhizoids?

Answer 7

Root-like structures on ferns.

Question 8

Is genetic variability in cultivated plants desirable or undesirable?

Answer 8

It is undesirable because we want uniform plants with certain selected traits for cultivars.

Question 9

What is the difference between pseudovivipary and cryptovivipary?

Answer 9

Pseudovivipary - a condition in which vegetative propagules replace some or all of the normal sexual flowers in the inflorescence.
Cryptovivipary - a condition in which the embryo grows continuously, but does not emerge from the fruit.

Question 10

List and describe four seed embryo types.

Answer 10

Basal - high endosperm to embryo ratio.
Axial - occupies the center of the seed.
Foliate - occupies the center of the seed.
Peripheral - surrounds inner mass of perisperm storage tissue.

Question 11

List four types of seed dormancy, causes of the dormancy, and what treatment it would take to overcome or break that type of dormancy.

Answer 11

Exogenous physical dormancy - Caused by a modification of the seed coverings, especially the outer integument layer, that may become hard, fibrous, or mucilaginous during dehydration and ripening. Can be overcome by breaking the seed coat.

Exogenous chemical dormancy - Chemicals present in the seed coat act as germination inhibitors or modify gas exchange. Inhibitors can be leached with water or eliminated by removing seed covering/coat.

Nondeep physiological dormancy - Embryo growth potential is inadequate to escape seed covering/coat. Can be overcome by short periods of stratification, and may also require light or darkness to germinate.

Intermediate physiological dormancy - Embryo growth potential is inadequate to escape seed covering/coat. Can be overcome by moderate periods (up to 8 weeks) of stratification.

Question 12

What is a plumule?

Answer 12

Develops into the shoot, bearing the first true leaves of a plant.

Question 13

What is parthenocarpy?

Answer 13

The development of fruit without pollination or fertilization.

Question 14

What is quiescence?

Answer 14

Lack of germination due to adverse environmental conditions.

Question 15

What is vivipary?

Answer 15

The condition in which seeds germinate in the fruit while it is still on the parent plant.

Question 16

What is it called when an embryo arises from the egg nucleus without fertilization, and the embryo is haploid?

Answer 16

Nonrecurrent apomixis

Question 17

What is it called when the embryo sac develops from the egg mother cell, but meiosis does not occur?

Answer 17

Gametophytic apomixis

Question 18

A perfect flower contains what?

Answer 18

Both stamens and pistils in the same flower.

Question 19

What is it called when plantlets are produced in the inflorescence of flowers?

Answer 19

Vegetative apomixis

Question 20

What is the optimum temperature range for most seeds to germinate?

Answer 20

77-86 degrees Fahrenheit

Question 21

What is it called when embryos develop outside of the embryo sac?

Answer 21

Sporophytic apomixis

Question 22

What happens to germination when imbibed seed is exposed to far red light, causing PFR to convert to PR?

Answer 22

Germination is inhibited

Question 23

A seed must have a water content of what percentage for germination to occur?

Answer 23

40-60%

Question 24

Plugs grown with LEDs with <10% blue light are generally more what compared to plants grown under HPS(High-Pressure Sodium lamps)?

Answer 24

Compact and greener

Question 25

During seed development, abscisic acid induces what?

Answer 25

Storage of proteins

Question 26

What are the three phases that seeds undergo before a seed can germinate after adding water, and what occurs in each?

Answer 26

Imbibition of water by the seed.
Lag phase where there is active metabolic activity but little water uptake.
Radicle protrusion occurs after a second period of fresh weight gain driven by additional water uptake.

Question 27

What occurs in the 4 phases of a seedling life cycle?

Answer 27

Embryonic - begins with the formation of a zygote, that grows into an embryo.
Juvenile - occurs with the germination of the seed into a seedling.
Transitional - the plant must reach a certain age which is measured by the number of nodes. It loses its characteristic juvenility.
Adult/mature - the plant has flowers and is ready to produce seeds.

Question 28

What is seed priming? Why would you prime seeds?

Answer 28

A treatment to prepare the seeds for germination.

You would prime seeds so you have a higher germination percentage.

Question 29

List three plant hormones that aid in seed development and indicate what role each plays in the development.

Answer 29

Auxin - essential for normal embryo and endosperm.
Gibberellins - required to sustain embryo growth in the first few days.
Abscisic acid - aids in seed maturation.

Question 30

What is the difference between interspecific hybrids and intergeneric hybrids?

Answer 30

Interspecific hybrids within a genus are designated with an “x” between the genus and species.
Intergeneric hybrids are formed between genera within a family and have an “x” before the genus name.

Question 31

What is totipotency?

Answer 31

The ability of a single cell to divide and produce all of the differentiated cells in an organism (contains all the genes necessary for growth and development).

Question 32

What are the differences between annuals, biennials, and perennials?

Answer 32

Annuals are plants that germinate, set seed, and die in one year.
Biennials are plants that require two growing seasons, with the first year being vegetative and the second being reproductive.
Perennials are plants that live for more than two years and repeat the vegetative-reproductive cycle annually.

Question 33

What is determinism?

Answer 33

The degree that a cell is committed toward a developmental stage.

Question 34

What is ontogeny?

Answer 34

Stages of growth and development at different ages.

Question 35

What is phenology?

Answer 35

Stages of growth and development during seasonal cycles controlled either by temperature or moisture supply.

Question 36

What is the difference between complete and incomplete flowers?

Answer 36

Complete flowers contain all of the floral components: sepals, petals, pistil, and stamens.
Incomplete flowers lack any one or more of these components.

Question 37

What is dichogamy?

Answer 37

Dichogamy - genetic trait in which male and female flowers on the same plant bloom at different times.

Question 38

What is the difference between protogyny and protandry?

Answer 38

Protogyny is when the female flower becomes receptive before the male sheds pollen.
Protandry is when the male sheds pollen before the female flower is receptive.