Reproduction and inheritance vocab

Question 1

Alleles

Answer 1

different forms of the same gene sometimes referred to as variants

Question 2

Asexual reproduction

Answer 2

involves only one individual and the offspring is identical to the parent. There is no fusion of gametes or mixing of genetic information.

Question 3

Carriers

Answer 3

individuals who are heterozygous for a recessive allele linked to a genetic disorder. Carriers have one healthy allele so are not affected themselves but they can pass on the affected allele to their offspring.

Question 4

Cystic fibrosis

Answer 4

an inherited disorder that affects the lungs, digestive, and reproductive system and is inherited through a recessive allele.

Question 5

Deoxyribonucleic acid

Answer 5

the molecule that is abbreviated to DNA. The genetic code is the sequence of nitrogenous bases A, C, T and G within the DNA molecules.

Question 6

Dominant allele

Answer 6

the phenotype will be apparent in the offspring even if only one of the alleles is inherited.

Question 7

Gamete

Answer 7

a haploid sex cell

Question 8

Genetic engineering

Answer 8

the process by which scientists can modify the genome of an organism by introducing a gene from another organism to give a desired characteristic.

Question 9

Genotype

Answer 9

the genetic makeup of an individual for a particular characteristic, for example eye colour.

Question 10

Heterozygote

Answer 10

individual with different alleles for a characteristic.

Question 11

Homozygote

Answer 11

individual with two identical alleles for a characteristic.

Question 12

Meiosis

Answer 12

two stage process of cell division that reduces the chromosome number of daughter cells. It is involved in making gametes for sexual reproduction.

Question 13

Mutation

Answer 13

a change in the genetic material of an organism.

Question 14

Natural selection

Answer 14

the process by which evolution takes place. Organisms produce more offspring than the environment can support. Only those that are most suited to their environment will survive to breed and pass their useful characteristics to their offspring.

Question 15

Nucleotide

Answer 15

a molecule made up of a sugar, a phosphate group, and one of four different bases. They are key units in the structure of DNA and RNA.

Question 16

Phenotype

Answer 16

the physical appearance (physical characteristics of an organism)

Question 17

Polydactyly

Answer 17

a dominant inherited disorder that results in babies born with extra fingers and/or toes

Question 18

Punnett square

Answer 18

a way of modelling a genetic cross and predicting the outcome using probability.

Question 19

Recessive

Answer 19

a phenotype that will only show up in the offspring if both the alleles coding for that characteristic are inherited.

Question 20

Selective breeding

Answer 20

speeds up natural selection by selecting animals or plants for breeding that have a required characteristic.

Question 21

Sex chromosomes

Answer 21

X and Y in humans, the combination of these chromosomes determines the gender of an individual.

Question 22

Sexual reproduction

Answer 22

involves the fusion of male and female gametes’ nuclei producing genetic variation in the offspring.

Question 23

Tissue culture

Answer 23

a modern way of cloning plants that allows thousands of new plants to be created from one piece of plant tissue.

Question 24

Y chromosome

Answer 24

smaller than the X chromosome, only one copy of this in each diploid cell is required to cause a male human.