Adding salt and sugar to food substances helps in preserving them for a longer duration. It is because excess salt and sugar

• cause rupturing of microbial cells

• cause change in the shape of microbial cells

• remove water from food

• plasmolyse the microbial cells

Root cap is absent in

• hydrophytes

• mesophytes

• halophytes

• xerophytes

23.

Hormone Adrenaline

• helps the body to adjust stress level when one is very angry or worried

• helps control height

• helps control balance of electrolytes in the body

• helps control level of sugar in the blood

The thumb of humans moves more freely than other fingers due to the presence of

• gliding joint

• hinge joint

• saddle joint

• pivotal joint

A common characteristic feature of plant sieve-tube cells and mammalian erythrocytes is

• absence of chloroplast

• absence of cell wall

• presence of haemoglobin

• absence of nucleus

The smallest of living organisms with cell wall are

• yeast

• cyanobacteria

• algae

• bacteria

Antibiotics are effective against

• influenza

• hepatitis A

• dengue fever

• cholera

Which of the following is immovable joint?

• Pivot-joint between head and neck

• Hinge-joint of elbow

• Joint between skull bone

• Ball and socket joint

Which blood corpuscle help in coagulation of blood?

• Lymphocyte

• Platelets

• Monocyte

• Red blood corpuscles

In yeast asexual reproduction takes place through

• Budding

• Fission

• Both (1) and (2)

• None of these