Cell division and Inheritance

Question 1

Nucleus

Answer 1

An organelle found in many living cells containing genetic information.

Question 2

Genes

Answer 2

A small section of DNA carrying genetic information. Each gene code for the particular combination of amino acid and tells the ribosomes how to put together amino acids to produce a specific protein. This determines the development and structure of organisms.

Question 3

Chromosomes

Answer 3

Thread-like structures carrying genetic info found in the nucleus. Made up of large molecules of DNA. It carries a large number of genes.

Question 4

Mitosis

Answer 4

It is the body cell division. The genetic material is copied and the cell divides once to form two genetically identical body cells. Occurs during growth and replacement of old cells. 46 chromosomes

Question 5

Gametes

Answer 5

Cells in reproductive organs divide to form gametes(sex cell)-sperm or egg. Contain a single set of chromosomes.

Question 6

Male gametes

Answer 6

Produced in the testes(sperm). 23 chromosomes. 50 chance to contain X or Y chromosome.

Question 7

Female gametes

Answer 7

Produced in the ovaries(egg). 23 chromosomes. Every egg contains X chromosome.

Question 8

Meiosis

Answer 8

The cell division that produces gametes. The genetic material is copied and the cell divides 2 times.

Question 9

Fertilisation

Answer 9

Fusion/joining of a male gamete and a female gamete.

Question 10

DNA

Answer 10

Is made up of very long strands, twisted to form a double helix, which contains four different compounds called bases.

Question 11

Amino acid

Answer 11

There are 20 different amino acids. They are used to make a protein.

Question 12

Alleles

Answer 12

Two versions of same gene. Alleles can be dominant or recessive.

Question 13

Genotype

Answer 13

Type of gene(allele)

Question 14

Phenotype

Answer 14

Physical characteristics.

Question 15

Cystic Fibrosis

Answer 15

Genetic disease carried on the recessive allele. The symptoms are excess of mucus in the lungs and pancreas. Breathing and digestion is effected.

Question 16

Polydactyly

Answer 16

Genetic disorder carried on the dominant allele. It causes an organism to have extra finger or toe.

Question 17

Heterozygous

Answer 17

Somebody who has two different alleles.

Question 18

Homozygous

Answer 18

Somebody who has two identical alleles.

Question 19

Enucleated

Answer 19

Nucleus from cell is removed.

Question 20

Selective breeding

Answer 20

Selectively develop particular characteristics of animals. by choosing which animal, males and females will sexually reproduce and have offspring together.

Question 21

Sexual reproduction

Answer 21

Requires 2 parent organisms and the fusion of gametes. The mixture of genetic info from parents leads to variety in the offspring.

Question 22

Asexual reproduction

Answer 22

Requires one parent organism and offspring are genetically identical. There is no genetic variation. Called clone.

Question 23

Plasimd

Answer 23

A genetic structure in a cell that can replicate independently of the chromosomes.

Question 24

Male

Answer 24

XY

Question 25

Female

Answer 25

XX

Question 26

Stem cell

Answer 26

Is an undifferentiated cell that can become any type of cell.

Question 27

Genetic information in a cell...

Answer 27

is held in the chemical DNA.

Question 28

Variation Importance

Answer 28

Caused by sexual reproduction. Increases the chance of survival of species, since it is more likely that a few of the offsprings will have the ability to survive.

Question 29

Genetic variation

Answer 29

A difference in the characteristics of individuals of the same kind may be due to differences in genes inherited

Question 30

Physical variation

Answer 30

A difference in the characters of individuals due to and the conditions in which they have developed.

Question 31

Different genes control the...

Answer 31

development of different characteristics.

Question 32

Some characteristics are controlled by...

Answer 32

single gene.

Question 33

Punnet square

Answer 33

Is a genetic diagram.

Question 34

Sex chromosomes

Answer 34

These two chromosomes are not same it can be X or Y chromosome.

Question 35

All 22 pairs of chromosomes are...

Answer 35

same.

Question 36

Monohybrid crosses

Answer 36

Genetic crosses that involve characteristics which are inherited on single genes.

Question 37

A sequence of 3 bases...

Answer 37

code for particular amino acid. The order of bases controls the order in which amino acids are assembled to produce a particular protein.

Question 38

Sickle cell anaemia

Answer 38

A genetic disorder causing the red blood cells become sickle-shaped. This means they do not carry oxygen effectively so you feel tired and you have a lack of energy. Carried on recessive allele.

Question 39

Heterozygous sickle cell anaemia

Answer 39

People are less likely to get malaria. Since red blood cells changed their shape to protect people against malaria.

Question 40

Down's syndrome

Answer 40

Caused by an extra copy of chromosome number 21, so the baby has 47 chromosomes. This causes a number of developmental problems in many areas, including brain, heart and the muscles.

Question 41

In body cell chromosomes are found in...

Answer 41

pairs.