Mitosis is a cell division that occurs in animal cells where each mother cell divides into 2 daughter cells. The number of chromosomes in the mother cell is identical to that in each resulting daughter cell. This is why mitosis is sometimes called an ” Identical Reproduction of Cells”.

Homologous chromosomes are the chromosomes which are similar but not identical. These are similar in length, gene position and centromere location. The stage in which paired homologous chromosomes get shortened and thickened is diplotene stage of Prophase1 of Meiosis
1. The homologous chromosomes undergo genetic recombination. The chromosomes reduce to homologous chromosomes in meiosis 1 and then to sister chromatids in meiosis
2. The homologous chromosomes first exchange their DNA in next phase they orient themselves randomly at the equator. Reduction division of homologus chromosomes takes place in meiosis.

Homologous chromosomes are the chromosomes which are similar but not identical. These are similar in length, gene position and centromere location. The stage in which paired homologous chromosomes get shortened and thickened is diplotene stage of Prophase1 of Meiosis
1. The homologous chromosomes undergo genetic recombination. The chromosomes reduce to homologous chromosomes in meiosis 1 and then to sister chromatids in meiosis
2. The homologous chromosomes first exchange their DNA in next phase they orient themselves randomly at the equator. Reduction division of homologus chromosomes takes place in meiosis.

• There are three stages of interphase: G₁ (first gap), S (synthesis of new DNA ), and G₂ (second gap).
• Cells spend most of their lives in interphase, specifically in the S phase where genetic material must be copied.
• The cell grows and carries out biochemical functions, such as protein synthesis, in the G₁ phase.
• During the S phase, DNA is duplicated into two sister chromatids, and centrosomes, which give rise to the mitotic spindle, are also replicated.
• In the G₂ phase, energy is replenished, new proteins are synthesized, the cytoskeleton is dismantled, and additional growth occurs.

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Just Think for what you had started...

Just Think for what you had started...

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Legendary Ye kaisa answer hai ?

It is composed of the following constituents:

• Phospholipids – forms the ultimate fabric of the membrane
• Peripheral proteins – present on the outer or inner surface of phospholipid bilayer but are not implanted in the hydrophobic core
• Cholesterol – folded between the hydrophobic tails of phospholipid membrane
• Carbohydrates – found to be attached to the lipids or proteins on the extracellular side of the membrane, leading to the formation of glycolipids and glycoproteins
• Integral proteins – found to be implanted in the phospholipid bilayer

Stems of various plants have undergone modifications to perform different functions.

Underground stems or storage stems:

Examples: Rhizomes, Corms, tubers

In ginger and banana, the underground stem is called a rhizome. The underground stem in Colocasia (arvi) is known as corm. Rhizomes and corms are underground stems, modified for the storage of food. Also, these stems help in vegetative reproduction of these plants. The tips of the underground stem in potato plants become swollen due to the accumulation of food. The potato is a tuber that helps in the storage of food and bears eyes on it. Subtended by a leaf scar, these eyes bear buds that give rise to new plants.

Supportive stems

Example: tendril

The stem in some weak plants bear thin, slender, and spirally-coiled structures called tendrils that help the plant get attached to nearby structures for support. Tendrils are found in cucumbers, melons, and other members of the family Cucurbitaceae.

Protective stems

Example: Thorns

The stem in bougainvillea and citrus plants (like lemon and orange) bear sharp, pointed structures called thorns, which provide protection to the plant from herbivores.

Photosynthetic stems

Example: Opuntia

The stem in the Opuntia is green. It carries out the process of photosynthesis in the absence of leaves.

Others stem modifications

In some plants, underground stems such as grasses spread in the soil and help in perenation. These stems are called runners.

The short lateral stem called the offset in some aquatic plants (such as Eichhornia) bears leaves and tufts of roots at the node and gives rise to new plants.

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• The body surface of Annnelids is distinctly marked out into segments or metamere and, hence, the phylum name Annelida.
• They exhibit organ-system level of body organization, bilateral symmetry,they are triploblastic, metamerically segmented and coelomate animals.
• Aquatic annelids possess lateral appendages called asparapodia. For example- Nereis

Preparation of second meiotic division occurs during interkinesis. Interkinesis or interphase II is a period of rest that cells of some species enter during meiosis, between meiosis I and meiosis II. No DNA replication occurs during Interkinesis. However, it does occur during the interphase I stage of meiosis. Each chromosome still consists of two chromatids.

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Synapsis: The pairing of homologous chromosomes is called synapsis. This occurs during the second stage of prophase I or zygotene.

Chiasmata: Chiasmata is the site where two non sister chromatids have crossed over. It represents the site of cross-over. It is formed during the diplotene stage of prophase I of meiosis.

The cell cycle was discovered by Prevost and Dumas (1824) while studying the cleavage of zygote of Frog. It is a series of stages a cell passes through, to divide and produce new cells.

This entire process where with the help of one single parent cell a new cell population grows and develops is known as the cell cycle. 

Mitosis	Meiosis
Interphase
Each chromosome replicates. The result is two genetically identical sister chromatids	Chromosomes not yet visible but DNA has been duplicated or replicated
Prophase
Prophase –Each of the duplicated chromosomes appears as two identical or equal sister chromatids, The mitotic spindle begins to form. Chromosomes condense and thicken	Prophase I – crossing-over recombination – Homologous chromosomes (each consists of two sister chromatids) appear together as pairs. Tetrad is the structure that is formed. Segments of chromosomes are exchanged between non-sister chromatids at crossover points known as chiasmata (crossing-over)
Metaphase
Metaphase -The chromosomes assemble at the equator at the metaphase plate	Metaphase I Chromosomes adjust on the metaphase plate. Chromosomes are still intact and arranged as pairs of homologues
Anaphase
Anaphase – The spindle fibres begin to contract. This starts to pull the sister chromatids apart. At the end of anaphase, a complete set of daughter chromosomes is found each pole	Anaphase I Sister chromatids stay intact. However, homologous chromosomes drift to the opposite or reverse poles
Mode of Reproduction
Asexual Reproduction	Sexual Reproduction
Occurrence
All the cells	Reproductive cells
Function
General growth and repair, Cell reproduction	Genetic diversity through sexual reproduction
Cytokinesis
Occurs in Telophase	Occurs in Telophase I and in Telophase II
Discovered by
Walther Flemming	Oscar Hertwig

the condition that distinguishes animals and plants from inorganic matter, including the capacity for growth, reproduction, functional activity, and continual change preceding death.

Coelom is a fluid filled space between the body wall and gut wall and lined by mesoderm on all of its sides. The presence or absence of body cavity or coelom plays a very important role in the classification of animals. Animals that possess a fluid filled cavity between body wall and digestive tract are known as coelomates. Annelids, mollusks, arthropods, echinodermates, and chordates are examples of coelomates. On the other hand, the animals in which the body cavity is not lined by mesoderm are known as pseudocoelomates.

Morphology:- Study of external features of an organism.

Morphology is the study of physical features of an organism.

Morphology is the branch of biological science that deals with the study of form, size, colour, structure and relative position of various parts of organisms.

Importance of morphology-

1. Knowledge of morphology is essential for recognition or identification of plants.
2. It gives information about the range of variations found in species.
3. Deficiency and toxicity symptoms are morphological changes that occur in response to shortage or excess of minerals.

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No we couldn't kill the viruses with medicines or vaccines because they have RNA

Gud mrng!!

Yes

The internal (thylakoid) membrane vesicles are organized into stacks, which reside in a matrix known as the stroma. All the chlorophyll in the chloroplast is contained in the membranes of the thylakoid vesicles. The stacks of thylakoid sacs are connected by stroma lamellae. The lamellae act like the skeleton of the chloroplast, keeping all of the sacs a safe distance from each other and maximizing the efficiency of the organelle.

Morphology is the branch of biological science that deals with the study of form, size, colour, structure and relative position of various parts of organisms.

Importance of morphology-

1. Knowledge of morphology is essential for recognition or identification of plants.
2. It gives information about the range of variations found in species.
3. Deficiency and toxicity symptoms are morphological changes that occur in response to shortage or excess of minerals.

Morphology is the form and structure of animals and plants..

The prophase I of meiosis occurs in the following stages:

1. Leptotene- This phase is the start of prophase-I. It is marked by the condensation of the chromosomes.

2. Zygotene- In this phase the homologous chromosomes start pairing up, called the synapsis. The synaptonemal complex starts building up. This complex is required to hold the homologous chromosomes at a place close to each other. Bivalent chromosomes are visible at this stage.

3. Pachytene- In this stage, this non-sister chromatids of homologous chromosomes exchange their parts, the process is called the crossing over. The attachment point of the crossing-over of the non-sister chromatids is called chiasma.

4. Diplotene- The crossing-over process is completed by this stage. The homologous chromosomes remain attched at the point of chiasma.

5. Diakinesis- The homologous chromosomes start to separate and synaptonemal complex disappears. The nuclear membrane also disappears.

The prophase I of meiosis occurs in the following stages:

1. Leptotene- This phase is the start of prophase-I. It is marked by the condensation of the chromosomes.

2. Zygotene- In this phase the homologous chromosomes start pairing up, called the synapsis. The synaptonemal complex starts building up. This complex is required to hold the homologous chromosomes at a place close to each other. Bivalent chromosomes are visible at this stage.

3. Pachytene- In this stage, this non-sister chromatids of homologous chromosomes exchange their parts, the process is called the crossing over. The attachment point of the crossing-over of the non-sister chromatids is called chiasma.

4. Diplotene- The crossing-over process is completed by this stage. The homologous chromosomes remain attched at the point of chiasma.

5. Diakinesis- The homologous chromosomes start to separate and synaptonemal complex disappears. The nuclear membrane also disappears.

Will anybody answer my question??

Species is the smallest and lower taxon in taxonomic hierarchy

1. These are sole members of bacteria 2. They are of two types (i) Eubacteria (ii) Archaebacteria 3. Some are speherical shaped some are comma shaped some are spiral shaped and some are rod shaped.. 4. Methogens ,halophiles & Thermoacidophiles etc....

1. The Monerans are unicellular organisms.

2. They contain 70S ribosomes.

3. The DNA is naked and is not bound by a nuclear membrane.

4. It lacks organelles like mitochondria, lysosomes, plastids, Golgi bodies, endoplasmic reticulum, centrosome, etc.

5. They reproduce asexually by binary fission or budding.

6. The cell wall is rigid and made up of peptidoglycan.

7. Flagellum serves as the locomotory organ.

8. These are environmental decomposers

9. They show different modes of nutrition such as autotrophic, parasitic, heterotrophic, or saprophytic.

The centrosome is an organelle that is the principal place where cell microtubules are organized. Also, it controls the cell division cycle, the stages which lead up to one cell dividing in two.

The centrosome has seemingly only evolved in animal cells. Fungi and plants use different structures to organize their microtubules. Although the centrosome has a key role in effective mitosis in animal cells, it is not mandatory.A centrosome is formed of two centrioles at right angles to each another. They are enclosed by a shapeless mass of protein.The centrosome replicates during the interphase of the cell cycle.

o please sona. I never concentrated on talking with my friends.. I always try to understand what the teacher teach.. so please stop guessing.. ??

U keep thinking in mind u dont understant physics. Look carefully at physics and then u will understand physics and will become a favourit subject.when a teacher falls in class u will concentrating on talking with ur friends.then u say that u dont understand physics.

You should practice it everyday. And within a month... You'll b like I only wanna study physics:)

can you please answer it briefly. please

The dimensional formula of current density is given by,

[M⁰ L^-2 T⁰ I¹]

Where,

• M = Mass
• I = Current
• L = Length
• T = Time