O

Question 1

Obesity

Answer 1

When a person is extremely overweight.

Question 2

Oesophagus

Answer 2

the muscular tube connecting the mouth with the stomach. Food passes down the oesophagus by a wave of muscular contraction called peristalsis.

Question 3

Oestrogen

Answer 3

A hormone secreted by the ovaries that stimulate the development of secondary sexual characteristics in females that help controls the menstrual cycle.

Question 4

Optic nerve

Answer 4

Nerve from the retina in the eye to the brain.

Question 5

Organ

Answer 5

A number of tissues working together to carry out a function in the body.

Question 6

Osmoregulation

Answer 6

the control of the water content of the body.

Question 7

Osmosis

Answer 7

The diffusion of water molecules through a partially permeable membrane, from a region of higher concentration of water molecules to a region of lower concentration (or from a region of higher water potential to a region of lower water potential).

Question 8

Ovary

Answer 8

Female sex organ where ova or eggs are produced.

Question 9

Ovulation

Answer 9

the release of an ovum (egg) from the ovary.

Question 10

Ovule

Answer 10

The structure inside the ovary of a plant that contains the female gamete. After fertilisation an ovule develops into a seed.

Question 11

Ovum

Answer 11

The female sex cell (gamete) produced in the ovary. Also called the egg.

Question 12

Oxygen debt

Answer 12

The extra oxygen that is needed by the body to respire lactic acid produced during anaerobic respiration.