Tag: structural organization in living organisms

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Questions Related to structural organization in living organisms

Multiple choice biology structural organization in living organisms structure of a plant cell levels of organisation in plants plant and animal cell

Match the following and find the correct combination.

(a) Cellulose (i) Cell wall of bacteria
(b) Chitinase (ii) Cell wall of plant cells
(c) Lysozyme (iii) Proteins
(d) Protease (iv) Cell wall of fungal wall
(v) RNA

  1. a-ii, b-iv, c-i, d-iii

  2. a-ii, b-i, c-iv, d-iii

  3. a-v, b-i, c-iii, d-ii

  4. a-v, b-iv, c-i, d-ii
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Cellulose is found in plant cell walls (a-ii), Chitinase breaks down chitin in fungal walls (b-iv), Lysozyme breaks down bacterial cell walls (c-i), and Protease breaks down proteins (d-iii).

Multiple choice biology structural organization in living organisms structure of a plant cell levels of organisation in plants plant and animal cell

Consider the following statements.
a. In plant cells, cytokines is starts with the formation of the phragmoplast.
b. Phragmoplast comprises interozonal microtubules and Golgi vesicles.
c. Primary cell wall is produced by microtubules.
Which of the statements are correct?

  1. $1$ and $3$
  2. $1$ and $2$
  3. $2$ and $3$
  4. $1, 2$ and $3$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

In plant cell division, cytokinesis typically starts with the formation of a phragmoplast, which comprises interzonal microtubules and Golgi vesicles. The primary cell wall is deposited later or formed during the process, but statement 3 regarding the primary cell wall being produced directly by microtubules in this context is not standard or part of the classic paired correct statements. Thus statements 1 and 2 are correct.

Multiple choice biology structural organization in living organisms structure of a plant cell levels of organisation in plants plant and animal cell

In a plant cell, DNA is present _______________.

  1. Only in chromosomes

  2. In chromosomes and chloroplasts

  3. In chromosomes, chloroplasts and mitochondria

  4. In chromosomes, chloroplasts mitochondria and ribosome's
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

DNA is found in the nucleus (chromosomes), as well as in semi-autonomous organelles like chloroplasts and mitochondria, which contain their own circular DNA. Ribosomes are composed of RNA and proteins, not DNA.

Multiple choice biology structural organization in living organisms structure of a plant cell levels of organisation in plants plant and animal cell

The plant cells wall in a cross-section appears to be made up of many layers due to the.

  1. Presence of large amount of cellulose in the wall

  2. Presence of lignin which prevents the folding cellulose micro fibrils

  3. Presence of different composition and structure of the lamellae which are added continuously as the wall grows

  4. Orientation of micro fibrils in the different lamellose of the wall that result in differences in the refraction of light so that layers of the wall are emphasized
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Plant cell walls appear layered in cross-section because the cellulose microfibrils in different lamellae are oriented in varying directions during growth, causing optical differences in light refraction that highlight distinct layers.

Multiple choice biology structural organization in living organisms structure of a plant cell levels of organisation in plants plant and animal cell

Choose the correct answers from the alternatives given.
When a plant cell is placed in pure water, it will

  1. Become rigid because of turgor pressure

  2. Lose water and wilt

  3. Swell and burst

  4. Alter its cell wall composition so that it becomes impermeable to water
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Pure water is a hypotonic solution that causes endosmosis. The water diffuses into the cell causing the cytoplasm to build up pressure against the wall. This pressure is called turgor pressure that causes rigidity of the cell and the cell does not burst. This turgor pressure is responsible for the enlargement and extension of the cells during growth.

Hence, the correct answer is 'Become rigid because of turgor pressure'.

Multiple choice biology structural organization in living organisms structure of a plant cell levels of organisation in plants plant and animal cell

Select the wrong statement with respect to the structure of a plant cell.

  1. Cellulosic cell wall is present inside the cell membrane

  2. Centrioles are usually absent

  3. A large central vacuole is present

  4. Golgi apparatus is formed of a number of unconnected units called dictyosomes
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Cell wall is the outer rigid protective and supportive covering of plant cells, fungi and some protists. Cell membrane is covering of protoplasm which occurs inside the cell wall. In plants the cell wall is made of cellulose.

So, the correct answer is 'Cellulosic cell wall is present inside the cell membrane'

Multiple choice biology structural organization in living organisms structure of a plant cell levels of organisation in plants plant and animal cell

Angiotensinogen is a protein produced and secreted by ________________.

  1. Juxtaglomerular (JG) cells

  2. Macula densa cells

  3. Endothelial cells (cells lining the blood vessels)

  4. Liver cells
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Angiotensinogen is a αα - globulin protein produced by liver cells. Renin changes angiotensinogen to angiotensin II (hormone) in response to fall in glomerular blood flow/glomerular blood pressure/GFR. Angiotensin II increases blood pressure and blood volume. 

Multiple choice biology structural organization in living organisms structure of a plant cell levels of organisation in plants plant and animal cell

With which of the following are basal bodies not associated?

  1. Plant cells

  2. Animal cells

  3. Centrioles

  4. Microtubules
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Basal body is also known as kinetosome. This is a short cylinder like a centriole, consists of nine triplet microtubules; it organizes assembly of the axoneme microtubules.
Animal cells posses centrioles and basal bodies, which are involved in cell division. 
Centrioles are cylindrical organelles that help in cell division. Basal bodies are formed from centrioles. 
Microtubules are filamentous structures formed from centrioles, which are involved in chromosomal separation during cell division. Nine triplets microtubules together form basal body. 
Plant cells do not possess centriole. Hence, it does not possess basal bodies formed from centrioles. 

Multiple choice biology structural organization in living organisms structure of a plant cell levels of organisation in plants plant and animal cell

What is the innermost portion of a mature plant cell wall called as?

  1. Primary cell wall

  2. Secondary cell wall

  3. Lamella

  4. Tonoplast
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
Cell wall consists of three layers: the primary cell wall, secondary cell wall and the middle lamella.
The middle lamella- It is the first layer formed during cell division. This layer is rich in pectin. It is the outermost layer, joins together adjacent plant cells and holds them together.
The primary cell wall- It is formed after the middle lamella. It is composed of pectin compounds, hemicellulose and glycoproteins. The layer consists of a framework of cellulose microfibrils, in a gel-like matrix. It is a thin, flexible and extensible layer.
The secondary cell wall- It is a thick layer formed inside the primary cell wall. It is extremely rigid and provides strength. It is composed of cellulose, hemicellulose and lignin.