Biology

Plant Transport and Physiology

2,012 Questions

Access a comprehensive set of questions on plant transport mechanisms and physiological adaptations. Topics include water movement, translocation of food, and plant responses to external stimuli. These biology questions are essential for medical entrance exams and other science competitive tests.

Xylem and phloem transportTranspiration and evaporationPlant adaptationsGeotropic and phototropic responsesWater absorption by rootsRespiration in roots

Plant Transport and Physiology Questions

Multiple choice biology kingdom monera, protista and fungi mycorrhiza classification of fungi useful and harmful microbes

Identify the wrong statement.

  1. Haploid endosperm is typical feature of Gymnosperm

  2. Brown algae have chlorophyll a and c and fucoxanthin

  3. Archegonia are found in Bryophyta, pteridophyta and Gymnosperms.

  4. Mucor has biflagellate zoospores.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Mucor is a microbial genus of molds commonly found in soil, digestive systems, plant surfaces etc. During sexual reproduction, compatible strains form short, specialized hyphae called gametangia. At the point where two gametangia fuse, a thick-walled, spherical zygosporangium develops. The zygosporangium typically contains a single zygospore.

So, the correct answer is 'Mucor has biflagellate zoospores'.

Multiple choice evs identifying the plants absorption of water from the soil root system the root system

A tissue with spiral thickening in the cell wall capable of absorbing water from air is known as

  1. Cork

  2. Velamen

  3. Epiblema

  4. Hypodermis
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Velamen is a spongy, multiple epidermis that covers the roots of some epiphytic or semi-epiphytic plants, such as orchid and Clivia species. The velamen of an orchid is the white or gray covering of aerial roots. It is many cell layers thick and capable of absorbing atmospheric moisture and nutrients. Often, the roots of orchids are associated with symbiotic fungi or bacteria. The latter may fix nutrients from the air. This functionality allows the orchid to exist in locations that provide a reproductive or vegetative advantage such as improved exposure or reduced competition from other plant species. The velamen also serves a mechanical function, protecting the vascular tissues in the root cortex, shielding the root from transpirational water loss and in many cases, adhering the plant to the substrate. Velamen is not found in breathing roots of halophytes, parasitic plants and all aerial roots. Cork, epiblema and hypodermis are not capable of absorbing water from air. 
Thus, the correct answer is option B.

Multiple choice evs identifying the plants absorption of water from the soil root system the root system

Most water absorption in plants takes place through

  1. Root cap

  2. Root apex

  3. Root hair

  4. Meristematic zone
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Plants absorb water through the entire surface using roots, stems and leaves. However, mainly the water is absorbed by roots. The area of young roots where most absorption takes place is the root hair zone. The root hairs are delicate structures which get continuously replaced by new ones at an average rate of 100 millions per day. The root hairs lack cuticle and provide a large surface area. They are extensions of the epidermal cells. They have sticky walls by which they adhere tightly to soil particles. As the root hairs are extremely thin and large in number, they provide enormous surface area for absorption. They take in water from the intervening spaces mainly by osmosis. So, most water absorption in plants takes place through root hair zone and not by root apex, root cap or meristematic zone.
Thus, the correct answer is option C.

Multiple choice evs identifying the plants absorption of water from the soil root system the root system

Which of the following is not a function of the roots?

  1. Anchoring of plant

  2. Absorption of water

  3. Absorption of mineral salts

  4. Preparation of starch
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Roots are the part of the plant that lies below the soil surface. It is an important part of a plant and plays many major roles such as acting as an anchor for the plant. Since it lies in the soil, it also absorbs and transports nutrients and water from the soil. It also prevents soil erosion.

Starch preparation is done by chlorophyll present in leaves.
Hence, the correct answer is option D.

Multiple choice evs identifying the plants absorption of water from the soil root system the root system

Velamen found in epiphytic roots is meant for

  1. Absorption of water from host

  2. Absorption of water from air

  3. Perennation

  4. Protection
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Velamen is a spongy, multiple epidermis that covers the roots of some epiphytic or semi-epiphytic plants, such as orchid and Clivia species. The velamen of an orchid is the white or gray covering of aerial roots. When dry and usually more green when wet as a result of the appearance of underlying photosynthetic structures. It is many cell layers thick and capable of absorbing atmospheric moisture and nutrients. Often, the roots of orchids are associated with symbiotic fungi or bacteria, the latter may fix nutrients from the air. So, velamen is meant for absorption of water from air and not for absorption of water from host, perennation or protection.

Thus, the correct answer is option B.

Multiple choice evs identifying the plants absorption of water from the soil root system the root system

The roots are important parts of the plant because

  1. The roots provide anchorage

  2. The roots help in making food

  3. The roots absorb water

  4. Both A and C
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Functions of root:-

  • It helps in the absorption of water and mineral.
  • Holds the soil hence provide anchorage.
  • Modify to store food.
  • In hydrophytes helps to take oxygen called pneumatophores.
  • Provide support to the plant body.
So the correct option is "Both A and C".

Multiple choice evs identifying the plants absorption of water from the soil root system the root system

A plant with epidermis specialised to absorb mositure from air is?

  1. Avicennia

  2. Vanda

  3. Rhizophora

  4. Jussiaea
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

A plant with epidermis specialized to absorb moisture from the air is Vanda because vanda is an epiphyte with modified epidermis called velamen. As it stays on the host plant branches, its roots hang in the air absorbing moisture from the atmosphere.

So, the correct option is 'Vanda'.

Multiple choice evs identifying the plants absorption of water from the soil root system the root system

Cells of quiescent centre have lower concentration of

  1. DNA

  2. Proteins

  3. RNA

  4. All of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
  • The quiescent centre is that part of the root-promeristems that contains the initials of epidermis, cortex and stele which divides less frequently and are present at the pole of cortex and stele.
  • In closed meristems, QC is hemispherical in shape whereas, in open meristem it is disc-shaped. 
  • The cells with QC have small dictyosomes, nuclei and nucleoli. 
  • These cells also have little endoplasmic reticulum, mitochondria and contain low concentrations of RNA, DNA and protein than the other cells of the root apex.
  • So, the correct answer is 'All of the above'.
Multiple choice evs identifying the plants absorption of water from the soil root system the root system

Cells of quiescent centre are characterised by

  1. Dense cytoplasm and prominent nuclei

  2. Light cytoplasm and small nuclei

  3. Dividing regularly to add to the corpus

  4. Dividing regularly to add to tunica
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
  • The quiescent centre or QC is a part of the root-promeristems that contains the initials of epidermis, cortex and stele.
  • The cells here divide less frequently as they are inactive and are present at the pole of cortex and stele.
  • The cells with QC have small dictyosomes, nuclei and nucleoli with little cytoplasm.
  • These cells also have little endoplasmic reticulum, mitochondria and contain low concentrations of RNA, DNA and protein than the other cells of the root apex.
  • So, the correct answer is 'Light cytoplasm and small nuclei'.
Multiple choice evs identifying the plants absorption of water from the soil root system the root system

Root cap regenerated/dead torn cells of root cap are replaced by the activity of

  1. Plerome

  2. Dermatogen

  3. Calyptrogen

  4. Periblem
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
Calyptrogen is the formative tissue found in the growing point of a root, giving rise to the root cap. Calyptrogen, as a rule, is characteristic of monocotyledonous plants. In most dicotyledonous plants, instead of calyptrogen, there is a tissue that also gives rise to the root’s absorbent external piliferous layer; this tissue is called dermatocalyptrogen.
The correct option is 'Calyptrogen'.

Multiple choice evs identifying the plants absorption of water from the soil root system the root system

Root region with thin-walled, small cells having sense cytoplasm is

  1. Region of cell elongation

  2. Maturation region

  3. Proximal to cell elongation zone.

  4. Distal to cell elongation zone
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The protoplasm of the cell is surrounded by a primary cell wall which is laid down as the cell begins to grow. It is thin and composed of cellulose, hemicellulose and pectic substances. Once growth has ceased a secondary cell wall may form inside the primary cell wall.

So, the correct option is 'Region of cell elongation'.

Multiple choice evs identifying the plants absorption of water from the soil root system the root system

Which of the following pairs is/are correct?
(A) Main root - Storage
(B) Lateral root - Absorption
(C) Root hair - Conduction

  1. All are correct

  2. A and B

  3. Only A

  4. None of these
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The region of cell differentiation or maturation is differentiated into root hairs. Most of the water absorption occurs through this region.

The roots are modified to form storage roots such as conical, fusiform, napiform, tuberous
Lateral roots extend horizontally from the primary root and this contributes to water uptake and nutrient uptake.

So, the correct option is 'A and B'


Multiple choice bio-chemistry unit of living - cell eukaryotic cell kinds of cell introduction to eukaryotic cell

Read the following statements w.r.t. meristematic cells:
(i)   Cells have dense cytoplasm with a prominent nucleus.
(ii)  Cells possess well-developed mitochondria, plastids, and endoplasmic reticulum.
(iii) Cells possess the property to divide continuously.
(iv) Apical meristems produce primary tissues.
(v)  During formation of leaves and elongation of the stem, some cells left behind from shoot apical meristem, constitute the axillary bud.
How many of the given statements are correct?

  1. Five

  2. Four

  3. Three

  4. Two
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
Properties of Meristematic Cells
Cells within meristematic tissues have special characteristics that make them unique when compared to cells in mature, specialized plant tissue. Cells within meristematic tissue are self-renewing, meaning that every time they divide, one new cell remains meristematic, while the second heads off to become a programmed or specialized mature cell.

Additionally, all cells within meristematic tissue are living, while other plant tissue can be made of both living and dead cells. Meristematic cells have thin cell walls, small or no vacuoles, which are stored organelles, and large prominent nucleus. This compares to the thick walls and small nucleus of programmed cells, which also have one or more large vacuoles. Also, meristematic cells contain a significant volume of dense liquid, while specialized cells have only a small quantity of thin liquid. 

Except for the statement that the cells possess well-developed mitochondria, plastids, and endoplasmic reticulum all the other statements are true.

So the correct option is 'Four'.
Multiple choice biology movement and locomotion in living organisms movements in plants coordination in plants tropic and nastic movements in plants

Cholodny-Went theory is related with 

  1. Turgor movement

  2. Chemotropism

  3. Phototropism

  4. Phototropism and geotropism
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The Cholodny-Went model, proposed in 1927, is an early model describing tropism in emerging shoots of monocotyledons, including the tendencies for the shoot to grow towards light (phototropism) and the roots to grow downward (gravitropism). In terms of phototropism, the Cholodny-Went theory proposes that:

(a) Auxin is synthesized in the coleoptile tip, 
(b) The coleoptile tip perceives the asymmetric illumination and this causes auxin to move into the un-irradiated side,
 (c) Auxin moves down the coleoptile so that lower regions develop an auxin asymmetry,
(d) The higher auxin concentration on the un-irradiated side causes the coleoptile to bend toward the light source.
Thus, the correct answer is option D.