Barr-body in mammals represents

• one of the two X-chromosomes in the cells

• all heterochromatin of male and female cells

• Y-chromosome of male

• all heterochromatin of female cells

Stomata of CAM plants

• open during the night and close during the day

• never open

• are always open

• open during the day and close at night

Which one of the following is categorised under living fossils?

• Selaginella

• Metasequoia

• Pinus

• Cycas

Mycorrhiza is an example of

• endoparasitism

• decomposers

• symbiotic relationship

• ectoparasitism

In sugarcane plant, ¹⁴CO₂ is fixed in a malic acid, in which the enzyme that fixes CO₂ is

• ribulose phosphate kinase

• fructose phosphatase

• ribulose biphosphate carboxylase

• phosphoenol pyruvic acid carboxylase

Which one of the following is wrong in relation to photorespiration?

• It is a characteristic of C₄ -plants

• It is a characteristic of C₃ -plants

• It occurs in chloroplasts

• It occurs in daytime only

Cessation of menstrual cycle in women is called

• menopause

• lactation

• ovulation

• parturition

Discontinuous variations are

• essential features

• acquired character

• non-essential changes

• heritable changes

Boron in green plants assists in

• photosynthesis

• sugar transport

• activation of enzymes

• acting as enzyme cofactor

Chlorenchyma is known to develop in the

• spore capsule of a moss

• pollen tube of Pinus

• cytoplasm of Chlorella

• mycellium of a green mould such as Aspergillus