The controlling centre of cell is

• nucleus

• nucleolus

• mitochondria

• ribosome

In human beings, which hormone acts as a mild growth hormone?

• Prolactin

• Oestrogen

• Progesterone

• Cortisol

Kidney stones are crystals of

• sodium chloride

• silica

• calcium oxalate

• potassium chloride

Iron is stored in bone marrow as

• haemosedrin

• ferritin

• haematin

• None of these

In testis of frog, there are no

• Sertoli cells

• spermatocytes

• spermatids

• intestinal cells

One difference in breathing mechanism of frog and rabbit is that

• expansion of frog's lungs is not much

• abdominal movements more in frog

• diaphragm and rib muscles play important role in rabbit

• air reaching frog's lungs is to cool

All the following are the properties of skeletal muscles except

• excitability

• contractility

• rhythmicity

• toxicity

During mitosis nuclear membrane disappears at

• early prophase

• late prophase

• metaphase

• anaphase

Pepsin acts in

• basic medium

• acidic medium

• neutral medium

• All of these

Red muscle cells are rich in

• only myosin

• haemoglobin and glucose

• lactic acid and acetic acid

• myoglobin and cytochrome