Monocot vs Dicot Roots

Question 1

What are the characteristics of a monocot root?

Answer 1

Pericycle,endodermis,big pith, no secondary growth, adventitious roots, no hypothermis, stele, vascular bundles scattered.

Question 2

What are the characteristics of a dicot root?

Answer 2

no pith in the roots, stele, endodermis, pericycle, secondary growth, tap root system. vascular bundle in a ring

Question 3

What are the characteristics of a dicot stem?

Answer 3

Vascular tissue usually arranged in ring, pith is distinct and centrally located, secondary xylem and phloem, epidermis, and cortex

Question 4

What are the characteristics of a monocot stem?

Answer 4

no pith, primary growth(no cambia), vascular bundles scattered

Question 5

What is velamen and what plant is it in?

Answer 5

Multi-layered epidermis and it is in the orchid

Question 6

Consider the way in which roots grow and the habitat they are adapted to.

Answer 6

Roots punch their way though abrasive soil, so a root cap protects the fragile apical meristem, lateral roots originate internally (from the pericycle) since external buds might be damaged during growth, and branching is concentrated at the base of the root (where elongation has stopped) so that lateral roots won’t be worn off as the main root lengthens. (Root hairs, which increase surface area and thus water absorption, also form only after elongation has stopped). Roots are generally supported by the soil, and so don’t need collenchyma for flexible support, though roots of trees do become woody (sclerenchyma + secondary xylem) to help anchor the tree into the soil.

Question 7

In which longitudinal zone of the root do you find lateral roots forming? Compared to stems

Answer 7

Lateral roots form in the zone of maturation, since the root is no longer elongating there and so they are not in danger of getting snapped off.

Question 8

Consider the way in which stems grow and the habitat they are adapted to.

Answer 8

Stems grow in the air and root grow in the abrasive soil so stems can branch from the outside, while roots protect their young branches by starting to branch from the inside.

Question 9

Aerial stems have what type of tissues?

Answer 9

Aerial stems lack the support of soil, and so often have collenchyma and sclerenchyma tissues to help hold them upright.

Question 10

What do apical meristems have on them in the winter.

Answer 10

The apical meristem may have bud scales during the winter to protect it from desiccation, but once it begins growing does not need extra protection from the environment.

Question 11

What is chlorophyll and anthocyanins?

Answer 11

Stems develop pigmentation for photosynthesis (chlorophyll) and to protect them from excess light (anthocyanins).

Question 12

Branching occurs where and where is it concentrated

Answer 12

Branching occurs from external buds, and is concentrated at the base of the stem to avoid shading of lower branches by upper ones and to increase stability

Question 13

Stems have leaves along what type of length and why is this?

Answer 13

Stems may have leaves along their entire length, as there is no danger of damaging leaves during periods of rapid growth (air is not abrasive).

Question 14

How do roots increase their surface area and how are roots different from the stems?

Answer 14

While roots work to increase surface area (via root hairs) and thus increase ability to absorb water, stems and their leaves work to reduce the impact of surface area (by covering it with a cuticle or by actually decreasing it) and thus reduce water loss

Question 15

What are the characteristics of a monocot leaf?

Answer 15

parallel leaf

Question 16

What are the characteristics of a dicot leaf?

Answer 16

netted leaf

Question 17

What is sunken stomata

Answer 17

Sunken stomata are a feature of many plants in deserts and other dry environments. Stomata are tiny holes, generally on the bottom surfaces of leaves, that allow for gas exchange and the release of water vapor. In moist environments, this is often necessary because the plants take in more water than is necessary for photosynthesis. It is not necessary in deserts, but because of the need for stomata for gas exchange, plants in dry environments cannot prevent some water loss. They minimize this loss through structures like sunken stomata.

Question 18

What is the thick waxy cuticle?

Answer 18

Other plant adaptations to life in dry environments include waxy cuticles, rolled leaves and small needle-like leaves. Waxy cuticles both prevent water loss directly and reflect heat, a major cause of water loss through evaporation. Rolled leaves keep their stomata inside, slowing water loss in the same way as sunken stomata. Needle-like leaves both reduce surface area and, in the case of some plants, act as a defense against herbivores.

Question 19

What are bulliform cells?

Answer 19

Bulliform cells are large, bubble-shaped epidermal cells that occur in groups on the upper surface of the leaves of many grasses. Loss of turgor pressure in these cells causes leaves to “roll up” during water stress. During drought, the loss of moisture through vacuoles induces bulliform cells to cause the leaves of many grass species to close as the two edges of the grass blade fold up toward each other. Once adequate water is available, these cells enlarge and the leaves open again. Folded leaves offer less exposure to sunlight, so they are heated less thus reducing evaporation and conserving the remaining water in the plant and occur on the leaves of many monocotyledons but are probably best known in grasses. They are thought to play a role in the unfolding of developing leaves and in the rolling and unrolling of mature leaves in response to alternating wet and dry periods.

Question 20

What is Krantz anatomy?

Answer 20

Their vascular bundles are surrounded by two rings of cells; the inner ring, called bundle sheath cells, contains starch-rich chloroplasts lacking grana, which differ from those in mesophyll cells present as the outer ring.

Question 21

What does covering hairs do for the leaves?

Answer 21

covering of hairs- hairs on underside of the leaf will slow airflow and putting hairs over the surface of the skin-slow evaporation

Question 22

What does fibers under the epidermis help with?

Answer 22

fibers under the epidermis- pine leaves makes the leaves waxy and heavy and hard stiff structure- prevents wilting and tissue damages and poky less eaten. Pines keep their leaves

Question 23

What are succulence leaves?

Answer 23

They are use to a dry habitat and they store water