Definition of terms.

Question 1

What is the term of tissue?

Answer 1

A group of similar cells working together to perform a particular function.

Question 2

What is the definition of organ?

Answer 2

It is a group of different tissues working together to carry out a particular set of functions.

Question 3

What is the definition of diffusion?

Answer 3

It is the net movement of substance from a region of higher concentration to a region of lower concentration, down the concentration gradient, until all the substance becomes evenly spaced out.

Net movement of substance from region of higher concentration to lower concentration.

Question 4

What is the definition of osmosis?

Answer 4

It is the net movement if water molecules from a region of higher water potential to a region of lower water potential, across a partially permeable membrane.

Question 5

What is the definition of enzymes?

Answer 5

It is proteins made by cells, which speed up the rate of chemical reactions, without themselves being chemically changed at the end of the reactions, and can be reused.

Question 6

What is the definition of photosynthesis?

Answer 6

It is a process whereby green plants absorb carbon dioxide and water in the presence of light energy. Which is absorbed by chlorophyll in chloroplasts to synthesize glucose and oxygen.

Word equation:
carbon dioxide + water → glucose + oxygen
↑
light + suitable temperature
Chlorophyll

Question 7

What is the definition of transpiration?

Answer 7

It is loss of water vapour mainly from the stomata of leaves of a plant.

Question 8

What is the definition of translocation?

Answer 8

It is the transport of manufactured food substances(e.g. sugar, amino acids) from leaves to other parts of the plant through the phloem.

Question 9

What is the definition of aerobic respiration?

Answer 9

It is the breakdown of food substances in the presence of oxygen with the release of large amounts of energy and carbon dioxide and water as waste products.

Word equation:
glucose + oxygen → carbon dioxide + water

Question 10

What is the definition of anaerobic respiration?

Answer 10

The breakdown of food substances in the absence of oxygen with the release of smaller amounts of energy.

Word equation:
in human muscles - glucose → lactic acid
in yeast - glucose → ethanol + carbon dioxide

Question 11

What is the definition of reproduction?

Answer 11

The production of new offspring organisms from parent organism(s) of the same species.

Question 12

What is the definition of asexual reproduction?

Answer 12

It is the process resulting in the production of genetically identical offspring from one parent.

Question 13

What is the definition of sexual reproduction?

Answer 13

It is the process involving the fusion of nuclei to form a zygote and the production of genetically different offspring.

Question 14

What is the definition of pollination?

Answer 14

The transfer of pollen grains from the mature anther to the stigma.

Question 15

What is the definition of self-pollination?

Answer 15

The transfer of pollen grains from an anther to a stigma of the same flower or a different flower of the same plant.

Question 16

What is the definition of cross-pollination?

Answer 16

The transfer of pollen grains from an anther of a flower to a stigma of a flower of a different plant of the same species.

Question 17

What is the definition of fertilization?

Answer 17

It is the fusion of nuclei of male and female gametes to form a zygote.

Question 18

What is the definition of Sexually transmitted infections(STIs)?

Answer 18

They are diseases that are transmitted due to contact of infected body fluids(e.g. seminal fluid, vaginal fluid, blood & etc.)

Question 19

What is the definition of haploid and diploid?

Answer 19

Haploid (n): one set of chromosomes. (Half the number, gametes(e.g. sperms &egg))
Diploid (2n): two sets of chromosomes.

Question 20

What is the definition of reflex action?

Answer 20

An automatic, immediate response to a specific stimulus without conscious control.

• Fast
• involuntarily/automatic/innate
• always involves a stimulus and the same response

Question 21

What is the definition of reflex arc?

Answer 21

The shortest pathway by which nerve impulses are transmitted from the receptor to the effector in a reflex action.

Question 22

What is the definition of irritability(sensitive)?

Answer 22

The ability of an organism to sense changes(e.g. lights/sound) in the environment and respond to it accordingly.

Question 23

What is the definition of focusing?

Answer 23

It is the adjustments of the lens of the eye so that clear images of objects at different distances are formed on the retina.

Question 24

What is the definition of hormones?

Answer 24

Hormones are chemical substances produced in minute/very small quantities by endocrine glands. They are transported by blood to target organ(s), where they alter the activity of the target organ(s). After they have performed their functions, they are broken down by the liver and excreted by the kidneys.

Question 25

What is the definition of endocrine glands?

Answer 25

It is a tissue or an organ, which produces and secrete hormones directly into the bloodstream, rather than through a duct.

Question 26

What is the definition of nucleotide?

Answer 26

It consists of three components which are phosphate, sugar and the base.

Question 27

What is the definition of deoxyribonucleic acid?

Answer 27

It consists of two polynucleotide chains twisting around each other to form a double-helix. The sugar-phosphate backbones of both strands lie on the outside of the DNA molecule, with the nitrogenous bases occupying the centre of the molecule. The two strands run in the opposite directions, making them anti-parallel. The two strands are held together by hydrogen bonds between the nitrogenous bases of opposite strands. A polynucleotide chain consists of a nucleotide.

Question 28

What is the definition of a gene?

Answer 28

It is a (short) segment of DNA which contains a sequence of bases found on nucleotides. Which is responsible for the specific physical traits/characteristics(e.g. eye colour) in a person and it also controls the synthesis of important proteins. (e.g. enzymes)