B13: Reproduction

Question 1

What is sexual reproduction?

Answer 1

Involves a mixture of genes and characteristics from two parents or two gametes that are genetically different.

Question 2

What is 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

How many chromosomes does a sperm cell have?

Answer 3

23

Question 4

What is a “Gamete”?

Answer 4

Is a sex cell, that contains half the number of chromosomes than a normal body cell e.g. sperm cell and egg cell.

Question 5

What is an allele?

Answer 5

It is a different form of the same gene sometimes referred to as variants.

Question 6

What is a base?

Answer 6

It is a nitrogenous compound that makes up part of the structure of DNA and RNA. They are represented by the letters A, T, C, and G

Question 7

What is a carrier? (in terms of people)

Answer 7

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 8

What is cystic fibrosis?

Answer 8

It is an inherited disorder that affects the lungs, digestive, and reproductive system and is inherited through a recessive allele. It prevents the mmovements of certian substances from one side to the other. Lungs get clogged up which can prevent them from working properly. Pancreas struggles to secrete enzymes.

Question 9

What is a dominant allele?

Answer 9

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

Question 10

What is genetic engineering?

Answer 10

The process by which scientists can manipulate and change the genotype of an organism.

Question 11

What is the genotype?

Answer 11

The genetic makeup of an individual for a particular characteristic, for example, hair or eye colour.

Question 12

Define a heterozygote.

Answer 12

An individual with different alleles for a characteristic.

Question 13

Define a homozygote.

Answer 13

An individual with two identical alleles for a characteristic.

Question 14

What is meiosis?

Answer 14

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

Question 15

Define the term ‘mutation’

Answer 15

A change in the genetic material of an organism.

Question 16

What is natural selection?

Answer 16

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 on their useful characteristics to their offspring.

Question 17

What is a nucleotide?

Answer 17

It is 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 18

What is a phenotype?

Answer 18

It is the physical appearance/biochemistry of an individual for a particular characteristic.

Question 19

What is polydactyly?

Answer 19

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

Question 20

What is a punnet square diagram?

Answer 20

It is a way of modeling a genetic cross and predicting the outcome using probability

Question 21

What is a recessive gene?

Answer 21

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

Question 22

What does a sex chromosome do?

Answer 22

It carries the information that determines the sex of an individual.