( UNIT 05 ) Genetics

Question 1

Gene mapping

Answer 1

Determining the location of genes on chromosomes.

Question 2

List the Chromosome Mutations (4)

Answer 2

1. Deletion
2. Duplication
3. Translocation
4. Inversion

Question 3

Deletion

Answer 3

A piece of a chromosome is broken off and ‘deleted’.

Question 4

Duplication

Answer 4

An extra piece of a chromosome is attached to an existing chromosome, duplicating some genes.

Question 5

Translocation

Answer 5

A piece of a chromosome breaks off and attaches to a non-homologous chromosome.

Question 6

Inversion

Answer 6

A piece of a chromosome detaches, flips, then reattaches.

Question 7

What are sex-linked genes?

Answer 7

Genes located on the sex chromosomes (X or Y). The X chromosome has more sex-linked genes.

Question 8

Why are Recessive sex-linked traits more common in males than females?

Answer 8

Traits that are more common in males than in females due to the presence of a single X chromosome in males.

Question 9

Autosomes

Answer 9

Non-sex chromosomes. Humans have 22 pairs of autosomes.

Question 10

Structure of DNA

Answer 10

Double helix with alternating deoxyribose sugars and phosphate groups. Nitrogen bases: Adenine, Thymine, Cytosine, Guanine.

Question 11

DNA Replication

Answer 11

1. DNA unwinds and the bases separate.
2. Each strand serves as a template for the synthesis of a new complementary strand.
3. DNA polymerase adds nucleotides to the new strand.
4. Two identical DNA molecules are formed.

Question 12

Structure of RNA

Answer 12

Single helix with ribose sugar. Nitrogen bases: Adenine, Uracil, Cytosine, Guanine.

Question 13

Protein synthesis

Answer 13

The process of creating proteins from the instructions encoded in DNA. Consists of transcription and translation.

Question 14

Transcription

Answer 14

1. DNA unwinds and the gene’s DNA sequence is transcribed into mRNA.
2. RNA polymerase adds complementary RNA nucleotides.
3. mRNA is formed and can leave the nucleus.

Question 15

Translation

Answer 15

1. mRNA attaches to a ribosome.
2. tRNA brings the correct amino acids to the ribosome.
3. Amino acids are joined together to form a protein.

Question 16

Gene regulation

Answer 16

The ability of an organism to control which genes are transcribed in response to the environment.

Question 17

Hox genes

Answer 17

Genes that determine the body plan of an organism and code for transcription factors. Important in embryonic stem cells.

Question 18

Least dangerous gene mutation

Answer 18

Substitution, because it only affects a single nucleotide.

Question 19

What are DNA fingerprints used for?

Answer 19

Used for identification purposes by analyzing unique patterns in an individual’s DNA.

Question 20

3 types of RNA

Answer 20

tRNA , mRNA , rRNA

Question 21

Restriction Enzymes in DNA fingerprinting

Answer 21

Cut long DNA molecules at different locations .

Question 22

Gel Electrophoresis

Answer 22

Process of moving molecules with an electric current ; gel is semi-permeable .

Question 23

Which chemical is radioactive in DNA fingerprinting?

Answer 23

Probes

Question 24

In karyotyping , which areas are darker on the chromosome ?

Answer 24

Regions rich in base pairs (AT)