Which form of reproduction is correctly matched?
Euglena transverse binary fission
Paramecium longitudinal binary fission
Amoeba multiple fission
Plasmodium binary fission
Which of the following match is correct?
Emphysema : reduction of surface area of alveoli and bronchi
Pneumonia : occupational disease with asbestos
Silicosis : inflammation of alveoli
Asthma : excessive secretion of bronchial mucus
XO-chromosomal abnormality in human beings causes
Turner's syndrome
Down's syndrome
Klinefelter's syndrome
None of these
Wings of pigeon, mosquito and bat show
divergent evolution
atavism
convergent evolution
all of these
Beta diversity is diversity
in a community
between communities
in a mountain gradient
on a plain
Which of the following is correct match?
Disease | Pathogen |
Wilt disease | Synchytrium |
Citrus canker | Xanthomonas |
Red rot of sugarcane | Ustilago |
Powdery mildew | Fusarium |
B.
Citrus canker | Xanthomonas |
Citrus canker is a bacterial disease. It is caused by bacteria Xanthomonas citri which is aerobic, rod shaped and monotrichous. It is a world wide disease of most Citrus plants but the most susceptible are grape fruits. sweet orange, lime and lemon. The symtoms first appear on the undersurface of leaves as small watery slightly raised, round light green spots that finally rupture to form corky crater like lesions or canker. Twigs, fruits, also develop lesions. The disease reduces the quantity and quality of fruits. Powdery mildew is caused by Erysiphe sp, red rot of sugarcane by Colletotrichum falcatum and wilt disease by Fusarium sp. Thus, they are all fungal diseases.
Apomixis is
formation of seeds by fusion of gametes
formation of seeds without syngamy and meiosis
formation of seeds with syngamy but no meiosis
none of the above