Genetics

Question 1

What is a genome

Answer 1

All the genetic material in a cell

Question 2

What is a chromatin

Answer 2

The genetic material of a cell consisting of DNA, proteins and some RNA

Question 3

How many chromosomes does a human cell have

Answer 3

46

Question 4

A cell with 23 paired chromosomes is called what

Answer 4

A diploid

Question 5

What is a haploid

Answer 5

Gametes (spermatozoa and ova) with only half of the normal complement, i.e. 23 chromosomes instead of 46.

Question 6

What are chromosomes that belong to the same pair called

Answer 6

Homologous chromosomes

Question 7

What is a karyotype

Answer 7

The complete set of chromosomes from a cell

Question 8

What is a chromosome

Answer 8

A long molecule of DNA that is coiled together with several proteins

Question 9

What are the first 22 pairs of chromosomes collectively known as?

Answer 9

Autosomes

Question 10

What are the pair 23 chromosomes known as and what do they determine.

Answer 10

They are sex chromosomes are determine the individuals gender

Question 11

What gender carries the Y chromosome

Answer 11

Male

Question 12

What gender is a child with 2 X chromosomes known as

Answer 12

Female

Question 13

What are genes

Answer 13

Genes are the cell’s hereditary units that control cellular structure and direct cellular activities.

Question 14

How many genes are there is a single chromosome

Answer 14

25000-30000

Question 15

What DNA made up of

Answer 15

Two chains of nucleotides

Question 16

Nucleotides consist of 3 subunits, what are these?

Answer 16

A sugar
A phosphate group
A nitrogenous base

Question 17

There are A,T,C,G binds in a DNA (in the middle) that bind together? What do the A binds bind to and ETC

Answer 17

A binds to T
C binds to G

Question 18

What are do the A,T,C,G, binds stand for

Answer 18

Adenine
Guanine
Thymine
Cytosine

Question 19

What maintain the 3D coiled shape of DNA

Answer 19

Histones

Question 20

What does mutation mean

Answer 20

Mutation means an inheritable alteration in the normal genetic make-up of a cell.

Question 21

What are some external factors that can cause mutation

Answer 21

X-Rays
Ultraviolet rays
Exposure to certain chemicals

Question 22

Mutation facts revision card

Answer 22

Most mutations are immediately repaired by enzymes present in the cell nucleus, and therefore cause no permanent problems.

However, sometimes the mutation is lethal, because it disrupts some essential cellular functions, causing cell death.

Often, the mutated cell is detected by immune cells and destroyed because it is abnormal.

Question 23

Some mutations do not kill the cell but instead alter its function in a way that can cause disease, what is an example of this.

Answer 23

Cancer

Question 24

How many amino acids are the building block of human proteins.

Answer 24

About 20 different amino acids

Question 25

What is mRNA

Answer 25

As the cell’s DNA is too big to leave the nucleus, an intermediary molecule is needed to carry the genetic instructions from the nucleus to the ribosomes in the cytoplasm, where proteins are made. This is called messenger (mRNA)

Question 26

What is gene expression

Answer 26

a gene’s DNA is used as a template for synthesis of a specific protein.

Question 27

What are the 2 steps of protein synthesis

Answer 27

The protein synthesis process consists of 2 steps: transcription and translation.

Question 28

What is the transcription stage of protein synthesis

Answer 28

The information encoded in a specific region of DNA is transcribed (copied) to produce a specific molecule of RNA (ribonucleic acid).

Question 29

What is the translation stage of protein synthesis

Answer 29

During translation, the RNA attaches to a ribosome, where the information contained in RNA is translated into a corresponding sequence of amino acids to form a new protein molecule

Question 30

What is meiosis

Answer 30

The division of 23 chromosomes in each sex chromosome coming together in fertilisation, creating a diploid amount of chromosomes.

Question 31

How many divisions are there in mitosis

Answer 31

1

Question 32

How many divisions are there in meiosis

Answer 32

2

Question 33

What is a dominant allele?

Answer 33

A dominant allele is an allele that dominates or masks the presence of another allele and is fully expressed, and the trait expressed is called a dominant trait.

Question 34

What is a recessive allele?

Answer 34

The allele whose presence is completely masked is said to be a recessive allele, and the trait it controls is called a recessive trait.

Question 35

What table is used to summarise all the alleles?

Answer 35

Punnet squares

Question 36

How many genes does the Y chromosome have

Answer 36

about 200

Question 37

How many genes does the X chromosome have

Answer 37

about 2000

Question 38

When is sex of the baby determined

Answer 38

Sex is determined at the time of fertilization by the presence or absence of a Y chromosome in the sperm. Thus, an individual’s sex is determined by the father’s chromosomes