Home
Class 12
BIOLOGY
Draw a labelled diagram of LS. of an emb...

Draw a labelled diagram of LS. of an embryo of grass (any six labels). (b) Give reason for each of the following: (i) Anthers of angiosperm flowers and described as dithecous. (ii) Hybrid seeds haveto be produced year after year.

Text Solution

Verified by Experts


(i) Anthers of angiosperms are described as dithecous because each bilobed anther has two theca. (ii) Hybrid seeds have to be produced year after year because progeny shows segregation and do not maintain hybrid characters
Promotional Banner

Similar Questions

Explore conceptually related problems

(a) Make a clearly labelled diagram of the inner ear of a human being. (b) Describe how each of the following is achieved in us (i) hearing (ii) balance

Draw a well labelled diagram of L.S of ovule showing the structure of embryo sac. Label any six parts.

(i)Draw a neat and labelled diagram of hair. (ii) Based on the diagram drawn above in (i), give a suitable term for each of the following descriptions: 1. Name the gland that secretes the oily, waxy substance called sebum. 2. A muscle causing the hair to stand up straight (goose bumps). 3. Protein present in this structure. 4. Cell divides rapidly and is responsible for the growth of the existing hair. 5. The pigment responsible for the colour of the skin. 6. Dead, keratinized superficial portion of the hair. 7. Small tube of cells that extends into the dermis region of skin.

(a) Draw a schematic labelled diagram of a fertilised embryo sac of an Angiosperm. (b) Describe the stage in embryo development in a dicot plant.

(a) Draw a schematic labelled diagram of a fertilised embryo sac of an Angiosperm. (b) Describe the stage in embryo development in a dicto plant.

(a) Draw a schematic labelled diagram of a fertilised embryo sac of an Angiosperm. (b) Describe the stage in embryo development in a dicot plant.

(a) Draw a labellel diagram of a moving coil galvanometer. Describe briefly its principle and working. (b) Answer the following: (i) Why is it necessary to introduce a cyclindrical soft iron core inside the coil of a galvanometer? (ii) Increasing the current sensitivity of galvanometer may not necessarily increase its voltage sensitivity. Explain, giving reason.

(i)Draw a neat and labelled diagram of the alimentary canal. (ii)Based on the diagram drawn above in (i), give a suitable term for each of the following descriptions : 1. The storage organ for bile juice. 2. A large J-shaped elastic bag. 3. Part of alimentary canal where complete digestion of food takes place. Finger-like minute projection that increases the surface of the small intestine. 5. A long muscular tube that leads from the pharynx till the stomach. 6. Part of both digestive and respiratory system. 7. A long region that divided into duodenum, jejunum, and ileum

(i)Draw a neat and labelled diagram of the human respiratory system. (ii) Based on the diagram drawn above in (i), give a suitable term for each of the following descriptions: 1. A small cartilage flap that covers the glottis. 2. A structure covered with C-shaped cartilaginous rings. 3.Muscular portion that separates the thoracic cavity and the abdominal cavity. 4. Scientific name of the voice box. 5. Cell organelle involved in aerobic respiration. 6. The chemical process that takes place inside the cells. 7. The physical process involves in exchange of gases between the organism and the environment.

(i)Draw a neat and labelled diagram of pectoral girdle with arm. (ii) Based on the diagram drawn above in (i), give a suitable term for each of the following descriptions : 1. Curved anterior bone of the shoulder (pectoral) girdle in vertebrates. 2. A shallow cavity of scapula that articulates with the head of the humerus. 3. Part of the skeleton that helps to articulate the limb bones to the main skeleton 4. Total number of bones present in the human body. 5. A long bone of the upper arm that articulates with the glenoid cavity of the scapula. 6. Irregular, small bones that look like pebbles and are present in two layers. 7. A large cup-shaped articular cavity of the hip bone which fits the large, round head of the thigh bone.