Ask questions which are clear, concise and easy to understand.

which hormones play essential roles in SPERMATOGENESIS

(1) Testosterone

(2) LH

(3) Oestrogens

(4) All

Posted by Aashka Shah (Apr 25, 2017 5:54 p.m.) (Question ID: 5034)

  • Answers:
  • Testosterone is the most essential hormone, LH and estrogen are also known to perform important functions during spermatogenesis.

    So the answer to this question can be (4) all of these.

     

     

    Correction : Option (3) must be estrogen.

     

     

    Answered by Payal Singh (Apr 26, 2017 11:14 a.m.)
    Thanks (1)
  • Add Answer

What is OSSIFIED ENDOSKELETON ?

Posted by Aashka Shah (Apr 23, 2017 9:01 p.m.) (Question ID: 5017)

  • Answers:
  • The endoskeleton that is enriched by calcium phosphate is known as ossified endoskeleton.

    Answered by Payal Singh (Apr 24, 2017 5:52 a.m.)
    Thanks (1)
  • Add Answer

Growth in plants is LIMITED

am I right

Posted by Aashka Shah (Apr 21, 2017 8:48 p.m.) (Question ID: 4988)

  • Answers:
  • No, growth in plant is unlimited due to continous cell division in meristematic tissue. plant grows throughout its life span.

    Answered by RAJENDRA SINGH (Apr 22, 2017 9:34 p.m.)
    Thanks (1)
  • Add Answer

(Q)   How the ethenol is produce in industrial field ?

(a) Saecheromisis

(b) Clostridium

(c) Aspergillus

(d) Streptomysis

Posted by Aashka Shah (Apr 21, 2017 7:01 p.m.) (Question ID: 4984)

  • Answers:
  • Ethanol is produced commerially by fermentation of sugar by Saechromisis bacterium.

    Answered by RAJENDRA SINGH (Apr 22, 2017 9:36 p.m.)
    Thanks (1)
  • Add Answer

Is GLAMUS a symbiotic fungi

Is RHIZOBIUM a symbiotic bacteria

PL. REPLY FAST

Posted by Aashka Shah (Apr 21, 2017 6:53 p.m.) (Question ID: 4983)

  • Answers:
  • yes, Glumus is a symbiotic fungi with roots of plants.

    Rhizobium is also a symbiotc bacteria with roots of leguminous plants.

    Answered by RAJENDRA SINGH (Apr 22, 2017 9:39 p.m.)
    Thanks (1)
  • Add Answer

what is lophodont and its examples

Posted by Aashka Shah (Apr 17, 2017 2:36 p.m.) (Question ID: 4922)

  • Answers:
  • Lophodont teeth are found in most of the herbivorous those grind their food thoroughly.

    They are easily identified by the pattern of ridges or lophs of enamel interconnecting the cusps on the crown. Lophodont molars have hard and elongated enamel ridges called lophs. These are either oriented along or perpendicular to the dental row. 

    These patterns of loph can vary from simple ring like structures such as in molar Rat to complex arrangement of series of ridges and cross ridges. E. g. Horse.

    Extreme form of this lophodonty is found in elephant.

    Answered by Amrita Mukherjee (Apr 17, 2017 3:42 p.m.)
    Thanks (1)
  • Add Answer

differentiatr between vegetative propagation and asexual reproduction 

Posted by swati bahar (Apr 17, 2017 11:59 a.m.) (Question ID: 4919)

  • Answers:
  • Vegetative reproduction:

    1. It is a form of asexual reproduction occur in plants where the new organish arises from the vegetative part of the parent plant.
    2. Here the set of genes present in the parent plant whose vegetative part is used for the reproduction is carried to next generation.
    3. By this process new generation arises without formation of any seeds or spores.
    4. Meristematic tissues are used for the vegetative reproduction, because they are capable of cellular differentiation hence give rise to an entire plant.
    5. All types of roots and shoots are capable of vegetative reproduction including stem, basal shoots, tuber, rhizomes, stolons, corms, bulbs and buds.

    Asexual Reproduction:

    1. This is the primary form of reproduction for all single celled organisms (e.g. bacteria, archea,), fungi, plants.
    2. Offsprings arise from a single parent therefore genes from one parent is inherited.
    3. Asexual reproduction embodied different types of reproduction process which varies from one another widely. Such as fission, budding, vegetative propagation, sporogenesis, fragmentation, agamogenesis, parthenogenesis.
    4. Asexual reproduction includes formation of spores in some of the cases.
    5. In this process no fusion of gametes happens and almost the chromosome number remain same all the time. 
    Answered by Amrita Mukherjee (Apr 17, 2017 4:33 p.m.)
    Thanks (0)
  • Add Answer

How tapetal cells can become bi nucleated?

 

Posted by BABY SINGH (Apr 17, 2017 12:02 a.m.) (Question ID: 4917)

  • Answers:
  • Ans. The cells are usually bigger and normally have more than one nucleus per cell. As the sporogenous cells undergo mitosis, the nuclei of tapetal cells also divide. Sometimes, this mitosis is not normal due to which many cells of mature tapetum become multinucleate.

    Answered by Payal Singh (Apr 17, 2017 6:15 a.m.)
    Thanks (0)
  • Add Answer

If a couple is unable to produce gametes then what type of ART should they be suggested? Why?

Posted by Swati Gusain (Apr 14, 2017 8:33 p.m.) (Question ID: 4885)

  • Answers:
  • If the couple is not able to produce gamets than IVF can be done by obtaining gamets from other individuals, followed by GIFT.

    Answered by RAJENDRA SINGH (Apr 16, 2017 8:50 p.m.)
    Thanks (0)
  • Add Answer

All reproductive track infection are STDs but all STDs are not RTIs ?Why?

Posted by Swati Gusain (Apr 14, 2017 8:30 p.m.) (Question ID: 4884)

  • Answers:
  • All reproductive track infections are STDs as it occurs during sexual inter course but some STDs like AIDS may occurs due to intra-venous infecion of other means too.

    Answered by RAJENDRA SINGH (Apr 16, 2017 8:56 p.m.)
    Thanks (0)
  • Add Answer

What is topography? 

 

Posted by Pallavi Kapoor (Apr 11, 2017 9:19 p.m.) (Question ID: 4845)

  • Answers:
  • In general the word ''Topography'' means the arrangement of the natural and artificial physical features of an area.

    In Biology, the word ''topography'' means the distribution of parts or features, on the surface of, or within, an organ or oganism. 

    Answered by Amrita Mukherjee (Apr 17, 2017 4:42 p.m.)
    Thanks (1)
  • Add Answer

What do you mean by suspend? 

Posted by Pallavi Kapoor (Apr 11, 2017 9:18 p.m.) (Question ID: 4844)

  • Answers:
  • The state in which the particles of a substance are dispersed but not totally dissolved in a fluid; the substance in this case is called suspended and the solution is called suspension.

    Here the particles are disperesed in the fluid due to agitation. If the suspension is allowed to settle then the suspended particles can be seen at the bottom.  

    Answered by Amrita Mukherjee (Apr 17, 2017 4:56 p.m.)
    Thanks (0)
  • Add Answer

Competition leads to evolution. Justify your answer. 

Posted by Pallavi Kapoor (Apr 11, 2017 9:17 p.m.) (Question ID: 4843)

  • Answers:
  • Resource availability is one of the major factors to determine the ecological dynamics of population or species. Fluctuation in resource availability can increase or decrease the intencity of resource competition. Resourse availability and competition can also cause the evolutionary changes. The Darwinian theory of ''struggle for existence'' reflects on how essential resource competition is, in shapping the evolution of all organisms when resources are limited. The general prediction based on classical competitive exclusion principle is that if specieses share the same limiting resource they can't co- exist in definitely. Competitively superior will out - compete the weaker ones. In a long enough time the selection pressuer caused by competetion can cause evolutionary changes which is termed as ''Natural Selection'' by Darwin.

     

    Answered by Amrita Mukherjee (Apr 17, 2017 5:49 p.m.)
    Thanks (1)
  • Add Answer

Why are biological control methods adopted in agricultural pest control? 

Posted by Pallavi Kapoor (Apr 11, 2017 9:15 p.m.) (Question ID: 4842)

  • Answers:
  • Biological pest control use the natural enemies of pests to kill or reduce their impact. Though biological controls may not completely eradicate a pest but they offer high advantages over other control methods, Such as:

    1. Biological pest control creates no chemical run off in water or soil. Therefore no possibilities for water pollution, imbalance in the soil contents, ground water pollution.
    2. They are very target specific. Biological control targets a very narrow range of pests, sometimes only a single species. So the control used for a particular pest mostly does not cause any harm to the other benefical organimsm living in the same area.
    3. This is a highly cost effective practice.
    4. If a biological control measure is established successfully, the species will remain stable population for generations without need for additional investments by human.   
    Answered by Amrita Mukherjee (Apr 17, 2017 6:21 p.m.)
    Thanks (1)
  • Add Answer

Why mother's milk is important for the early growth of child?

Posted by Alex A.K (Apr 09, 2017 7:26 p.m.) (Question ID: 4800)

  • Answers:
  • Mother's milk provides the ideal nutrition for infants. It has nearly perfect mix of vitamins, proteins, fats and all other essential nutritional elements for the baby.

    Mother's milk contains antibodies that help the baby fight against several viruses and bacteria during the initial growth stage. It helps the baby to grow its own immune system.

    Mother's milk lowers baby's risk of growing hypersensitivity, infections, respiratory illness and chances of diarrhea.

    Answered by Amrita Mukherjee (Apr 17, 2017 6:37 p.m.)
    Thanks (0)
  • Add Answer

Zona pellucida is secreted by ..

1 Primary oocyte 

2 Secondary oocyte

3 Both

4 none

Posted by Dr-Sachin Khatri (Apr 06, 2017 7:36 a.m.) (Question ID: 4735)

  • But ncert write it as secondary oocyte

    Posted by Dr-Sachin Khatri (Apr 06, 2017 10:39 a.m.)
  • Add Comment
  • Answers:
  • But according to ncert ans is secondary oocyte. ....

    Answered by Dr-Sachin Khatri (Apr 06, 2017 10:41 a.m.)
    Thanks (0)
  • 1 primary oocyte

    Answered by Aadarsh Girepunje (Apr 06, 2017 10:16 a.m.)
    Thanks (0)
  • Add Answer

Rearrange the following greenhouse gases in increasing order of their relative contribution to the total global warming:

N2O; CFC; CO2; CH4

Posted by Dev Divyansh (Apr 03, 2017 11:43 a.m.) (Question ID: 4695)

  • Answers:
  • Ans. CO2 > CH4>N2O > CFC

    Answered by Payal Singh (Apr 03, 2017 6:59 p.m.)
    Thanks (0)
  • Add Answer

What is biogenesis?

Posted by Devesh Srivastava (Apr 03, 2017 12:09 a.m.) (Question ID: 4691)

  • Answers:
  • The term biogenesis refers to the production of life from already- living matter or organisms.

    Answered by Payal Singh (Apr 03, 2017 7:02 p.m.)
    Thanks (0)
  • Add Answer

What are the differences between Litter and Detritus???

And between Pisciculture and Aquaculture????

 

Posted by Priyankaa Singh (Apr 01, 2017 4:41 p.m.) (Question ID: 4652)

  • What?? Is it a joke?? What's going on here?? Where are the teachers?? We need answers for our Questions...

    Posted by Priyankaa Singh (Apr 02, 2017 1:05 p.m.)
  • Add Comment
  • Answers:
  • Litter: This word refers to trash or waste products that has been disposed inappropriately at an inappropriate location. 

    HOWEVER

    Litterfall, plant litter, leaf litter, tree litter or soil litter all these words refer to dead plant material that have fallen to the ground.

    Detritus: refers to dead particulate organic material. It typically includes the bodys of fragments of dead organism as well as fecal material. Detritus is typically colonized by the communities of microorganisms which act to decompose or remineralize the material. In terrestrial ecosystem it refers as humus and in aquatic ecosystem it is refered as organic material suspended in water.

    Pisciculture: Fish farming or pisciculture involves raising fish commercially in tanks or enclosure usually for food.

    Aquaculture: It is also known as aquafarming. It is the farming of fish, crustaceans, molluscs, aquatic plants, algae and other aquatic organisms. Aquaculture involves cultivating fresh water and saltwater population under controlled condition. 

    Answered by Amrita Mukherjee (Apr 17, 2017 8:49 p.m.)
    Thanks (0)
  • Add Answer

How the gay are born

Posted by VIVEK KUMAR (Mar 29, 2017 4:35 p.m.) (Question ID: 4590)

  • Answers:
  • Gay are born due to wrong copying of sex chromosome that leads to some missing of addtional charecteristic.

    Answered by RAJENDRA SINGH (Mar 29, 2017 6:34 p.m.)
    Thanks (0)
  • Add Answer

Zoospores are the special asexual reproductive structures in lower organism like few algae and fungi right?? But what is the significance of those zoospores?? Do they fuse to form a new organism????

Posted by Priyankaa Singh (Mar 28, 2017 11:49 a.m.) (Question ID: 4563)

  • Answers:
  • Zoospores are asexually produced structure having following significance

    a. they are motile

    b. they contains same number of chromosome as parent body.

    c. they are produced in large number,

    Answered by RAJENDRA SINGH (Mar 28, 2017 6:37 p.m.)
    Thanks (1)
  • Add Answer

1.Which two scientists invented the genetic code?

Posted by Able Jenson (Mar 27, 2017 11:45 a.m.) (Question ID: 4547)

  • Answers:
  • james Watson,francis crick

    Answered by Krishan mittal (Mar 27, 2017 1:23 p.m.)
    Thanks (0)
  • Add Answer

What is the life span of Bat ?

Posted by SUYOG BHAGWAT (Mar 21, 2017 6:30 p.m.) (Question ID: 4346)

  • Answers:
  • Ans. almost 40 years.

    Answered by Naveen Sharma (Mar 21, 2017 7:43 p.m.)
    Thanks (0)
  • Add Answer

How is weed good for health??

Posted by chandan choudhary (Mar 16, 2017 6:18 a.m.) (Question ID: 3892)

Name a genus of baculovirus.why are they considered good biocontrol agent.

Posted by Arti Sah (Mar 14, 2017 12:18 a.m.) (Question ID: 3715)

  • Answers:
  • Ans. Nudeopolyhedrovirus is a genus baculovirus which are efficient bio-control agents.

    They are considered to be good bio-control agents because these viruses are excellent candidates for species-specific, narrow spectrum insecticidal applications and show no negative inpacts on plants, mammals, birds or even non-target insects.

    Answered by Naveen Sharma (Mar 14, 2017 2:44 p.m.)
    Thanks (0)
  • Add Answer

i am appearing this year 12 th exam with physics,chemistry,biology,english&music subjects. i want do 12 th exam with mathematics also.please guide me the proceder.

sanjay kumar

Posted by sanjay kumar (Mar 10, 2017 5:38 p.m.) (Question ID: 3444)

State the criteria used for determining a biodiversity spot

Posted by SHADAB ARAFAT (Mar 05, 2017 8:18 a.m.) (Question ID: 3077)

what is industrial melanism?

Posted by mohit bedi (Mar 03, 2017 11:22 p.m.) (Question ID: 3017)

can we draw diagrams using sketch pens in boards exam class12??

Posted by abhijeet Singh (Mar 01, 2017 2:52 a.m.) (Question ID: 2842)

  • Answers:
  • You don't need to waste your time in drawing diagrams using sketch pens. Use a sharpened pencil and draw the diagrams. Drawing diagrams with sketch pens won't fetch you any extra marks. Drawing the right diagram will surely get you marks. 

    Hope it helps you. All the best!

    Answered by Shweta Gulati (Mar 01, 2017 9:36 a.m.)
    Thanks (1)
  • Add Answer

What are somatic hybrids and soma clones?

Posted by Dinesh Kumar (Feb 24, 2017 7:01 p.m.) (Question ID: 2565)

  • Answers:
  • Ans. Somatic hybrids is produced when a hybrid is produced by fusion of somatic cells of two varieties or species.

    The plants produced through micropropagation technique that are genetically identical to the original plant from which they are produced are called Somaclones.

    Answered by Naveen Sharma (Feb 24, 2017 8:16 p.m.)
    Thanks (0)
  • Add Answer

Sponsored Links

Download Mobile App

banner

Subscribe by E-mail

For Latest News and Updates from myCBSEguide.com
Enter your email address:

Connect via Facebook

Sponsored Links