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Question 1

Palisade mesophyll

Answer 1

Tissue in leaves that contain many chloroplasts and are the main site of photosynthesis.

Question 2

Pancreas

Answer 2

The organ in the abdomen that produces digestive enzymes and makes insulin and glucagon that regulate the concentration of glucose in the blood.

Question 3

Partially permeable membrane

Answer 3

A membrane that allows small molecules to pass through, but does not allow large molecules to pass through.

Question 4

Passive immunity

Answer 4

Providing antibodies from another person or an animal; the person receiving the antibodies does not make the antibodies himself or herself.

Question 5

Pathogen

Answer 5

an organism that causes a disease.

Question 6

Pectinase

Answer 6

An enzyme that breaks down cell walls of plants.

Question 7

Peripheral nervous system

Answer 7

Nerves that arise from the brain and spinal cord and go to all the organs of the body.

Question 8

Peristalsis

Answer 8

A wave of muscular contraction that squeezes food down the oesophagus to the stomach.

Question 9

Pesticide

Answer 9

A Chemical that kills pests.

Question 10

Phagocyte

Answer 10

A type of white blood cell that ingests and destroys pathogen.

Question 11

Phagocytosis

Answer 11

A type of white blood cell that ingests and destroys pathogens.

Question 12

Phenotype

Answer 12

The physical or other features of an organisms due to both its genotype and enviroment.

Question 13

Phloem

Answer 13

The plant tissue that transports sugars and amino acids.

Question 14

Photosynthesis

Answer 14

Process by which plants manufacture carbohydrates from raw materials using energy from light.

Question 15

Phototropism

Answer 15

A growth response of a plant to the direction of light.

Question 16

Pituitary gland

Answer 16

A gland at the base of the brain that secrets hormones to controls the activity of other organs, e.g. kidneys, testes and ovaries.

Question 17

Placenta

Answer 17

The organ that connects a mammalian embryo to its mother and through which it receives food and oxygen and removes carbon dioxide and chemical waste.

Question 18

Plague

Answer 18

(1) a mixture of food remains, saliva and bacteria which can build up on the surface of teeth; (2) fatty deposit in the lining of an artery.

Question 19

Plasma

Answer 19

The liquid part of the blood which transports dissolved foods, urea, carbon dioxide and hormones.

Question 20

Plasmid

Answer 20

The liquid part of the blood which transports dissolved foods, urea, carbon dioxide and hormones.

Question 21

Plasmolysis

Answer 21

The separation of the cell membrane from the cell wall of a plant cell when water leaves the cell by osmosis.

Question 22

Platelets

Answer 22

Small pieces of cells that release substances that cause blood to clot.

Question 23

Pollination

Answer 23

The transfer of pollen from the anther of a flower to the stigma.

Question 24

Pollution

Answer 24

The release by humans of materials or energy that will harm the enviroment.

Question 25

Population

Answer 25

a group of individuals of the same species living in the same habitat at the same time.

Question 26

Population growth

Answer 26

Growth in numbers of a population. In absence of limiting factors growth is usually exponential.

Question 27

Predators

Answer 27

Animals that hunt and kill other animals for their food.

Question 28

Prey

Answer 28

Animals that are hunted and killed for food by predators.

Question 29

Producers

Answer 29

An organisms that makes its own organic nutrients usually using energy from sunlight through photosynthesis.

Question 30

Progesterone

Answer 30

A hormone secreted by the ovaries and by the placenta that maintains the lining of the uterus during the second half of the menstrual cycle and during pregnancy.

Question 31

Protease

Answer 31

An enzyme that breaks down proteins to amino acids.

Question 32

Protein-energy malnutrition

Answer 32

Form of malnutrition in which energy and protein are limited in the diet, e.g. marasmus and kwashiokir

Question 33

Proteins

Answer 33

Compounds made up of amino acids, which are needed for growth and repair of tissues in the body. They contain the elements carbon, hydrogen, oxygen, nitrogen and sulfur.

Question 34

Puberty

Answer 34

The age at which secondary sexual characteristics appear in boys and girls.

Question 35

Pulse

Answer 35

When the left ventricle of the heart contracts, it forces blood out of the heart along the arteries. The arteries swell and this can be felt as a pulse in various parts of the body, such as the wrist.

Question 36

Pupil

Answer 36

The hole through which light enters the eye. The size of the pupil is controlled by the iris.

Question 37

Pyramid of biomass

Answer 37

A way to show biomass at each tropic level in an ecosystem. the area of each horizontal bar is proportional to each mass of living material at each tropic level.

Question 38

Pyramid of numbers

Answer 38

A way to show numbers of organisms at each trophic level in an ecosystem. The area of each horizontal bar is proportional to the number of individuals at each tropic level.