Botany lecture notes

Difference between Protoxylem and Metaxylem: A Comparison Table


classification of xylem

Protoxylem vs Metaxylem
Similarities and Differences between Protoxylem and Metaxylem

Vascular bundles (fascicles) are the component of the stelar system in higher plants and their main function is the conduction of water, minerals and food materials. Typically the vascular bundle composed of xylem and phloem arranged together as bundles. In a young stem, both in dicots and monocots, the xylem of vascular bundles are differentiated into PROTOXYLEM and METAXYLEM based on the structural and functional difference of their elements. The present post describes the similarities and differences between Protoxylem and Metaxylem in a primary vascular bundle of a young stem.

Similarities between Protoxylem and Metaxylem

Ø  Both protoxylem and metaxylem can conduct water and minerals.

Ø  Both components contain living and dead cells.

Ø  Both are developed from the primary meristem, the pro-cambium.

Ø  Both contain tracheids, vessels and parenchyma.

Ø  Protoxylem and metaxylem develop only in primary vascular bundles.

Differences between Protoxylem and Metaxylem

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Free Net Life Science Study Materials

CSIR JRF NET Life Sciences Exam: December 2016: Model Question Paper- Set 1/5


csir net jrf december 2016 question paper

CSIR JRF NET Life Sciences Examination: December 2016
Model Question Paper with Answer Key and Explanations – Set 1/5

1. The metal component of Nitrogenase enzyme is:

a.       Mananese
b.      Molybdenum
c.       Copper
d.      Zinc

2. The only plant hormone which is NOT translocated from the cells producing it:

a.       Auxin
b.      Ethylene
c.       Cytokinin
d.      Gibberillic acid

3. Ribosomal rRNA in eukaryotes are transcribed by:

a.       RNA Polymerase I
b.      RNA Polymerase II
c.       RNA Polymerase III
d.      RNA Polymerase I and III

4. RNA-DNA hybrid always adopt A form because of:

a.       Steric hindrance of –OH group in RNA
b.      Steric hindrance of –OH group in DNA
c.       Coiling of the molecule
d.      Presence of Uracil base in RNA

5. Which plant is the most efficient converter of solar energy?

a.       Wheat
b.      Sugarcane
c.       Rice
d.      Banana

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Botany lecture notes

Anatomy of Dicot Stem: The Primary Structure – Key Points with PPT


Stem Structure Anatomy

Anatomy of Dicot Stem
Anatomy of the Primary Structure of Dicot Stem

“Biology is the study of complicated things that have the appearance of having been designed with a purpose….”
Richard Dawkins

Ø  The anatomy of dicot stem is studied by a T.S. (transverse section) took through the internode of the stem.

Ø  The components of cortex and stele are together known as Ground Tissue.

Ø  Anatomically the dicot stem has the following regions:

(1). Epidermis

(2). Cortex

a).  Hypodermis
b).  Outer cortex
c).   Inner cortex
d).  Endodermis

(3). Stele

a).  Pericycle
b).  Vascular bundles
c).  Medullary rays
d).  Pith

(1). Epidermis

Ø  Epidermis is the outermost layer, composed of parenchymatous cells.

Ø  Usually, epidermis composed of single layer of cells.

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mcq biology

Ecology Multiple Choice Questions Part 2 with Answer Key


environmental science test questions and answers

ECOLOGY MCQ-02
(Biology / Life Sciences MCQ: Multiple Choice Questions in Biochemistry)

MCQ on Ecosystem: Introduction Part 2
(Sample/Model/Practice Questions for CSIR JRF/NET Life Science Examination, ICMR JRF Exam, DBT BET JRF Exam, GATE BT and XL Exam, ICAR JRF NE Exam, PG Entrance Exam, JAM Exam, GS Biology Exam and Medical Entrance Exam)

1. Which of the following is NOT a characteristic of population?

a.       Sex ratio
b.      Natality
c.       Mortality
d.      Stratification

2. Which decade has been designated as the ‘Decade of Biodiversity’ by United Nations?

a.       2021-2030
b.      2011-2020
c.       2001-2010
d.      1991-2000

3. Decomposers which specifically act on the fecal matter of other organisms are called as:

a.       Heterophagic
b.      Allophagic
c.       Coprophagic
d.      Paraphagic

4. In a pond ecosystem, the top area where the production is greater than respiration (P/R >1) is termed as:

a.      Limnetic zone
b.      Profundal zone
c.       Benthic zone
d.      Tidal zone

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mcq biology

Ecology Multiple Choice Questions Part 1 with Answer Key


Ecology Quiz

ECOLOGY MCQ-01
(Biology / Life Sciences MCQ: Multiple Choice Questions in Biochemistry)

Ecosystem Concepts : Introduction Part 1/2
(Sample/Model/Practice Questions for CSIR JRF/NET Life Science Examination, ICMR JRF Exam, DBT BET JRF Exam, GATE BT and XL Exam, ICAR JRF NE Exam, PG Entrance Exam, JAM Exam, GS Biology Exam and Medical Entrance Exam)

1. The natural place where the organism or communities live is known as:

a.       Niche
b.      Habit
c.       Habitat
d.      Biome

2. Any features of an organism or its part which enable it to exist under conditions of its habitat is known as:

a.       Adaptive variation
b.      Adjustment
c.       Acclimatization
d.      Adaptation

3. According to Shelford’s low of tolerance, an organism with wide tolerance limit for environmental factor usually show:

a.       Wide distribution with low population size
b.      Wide distribution with high population size
c.       Narrow distribution with low population size
d.      Narrow distribution with high population size

4. Plants which grow under direct sunlight and those growing under shade are called as _______ and _______ respectively.

a.       Heliophytes and Sciophytes
b.      Sciophytes and Heliophytes
c.       Psamophytes and Heliophytes
d.      Heliophytes and Psamophytes

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