Exams Semester 2

Question 1

What does DNA stand for? Why is it an important molecule?

Answer 1

DNA stands for deoxyribonucleic acid

It is important because it contains genetic material

Question 2

What are the four bases that can be attached in an DNA strand? What are the three parts of a nucleotide?

Answer 2

Parts:
1) Phosphate group
2) Sugar/deoxyribose
3) base
Bases:
1)adenine
2) guanine
3) cytosine
4) thymine

Question 3

What holds DNA base pairs together in the double helix? Why are they signifcant

Answer 3

Hydrogen bonds

They break when DNA is replicating or making proteins

Question 4

Three types of RNA and functions

Answer 4

1) messenger RNA (mRNA)-carries info in DNA to the ribosomes
2) transfer (tRNA)-carries amino acids to the ribosomes
3) ribosomal (rRNA)-make up a ribosome

Question 5

What is a gamete? what are the two types of gametes?

Answer 5

a gamete is a sex cell. The other two types are sperm and egg cell

Question 6

Diploid Cell

Answer 6

2 cells, 2n, # of chromosomes

Question 7

Haploid Cell

Answer 7

1 cell, 1n, # of chromosomes

Question 8

What did Gregor Mendel do?

Answer 8

he is known as the father of genetics. He worked with pea plants and discovered the patterns of inheritance

Question 9

Why are males affected by X-linked disorders more than females?

Answer 9

they only have 1 gene on the x chromosome (XY)

Question 10

What is a “carrier” of a gene disorder mean?

Answer 10

carrier=heteroxygous

carries the genetic disease but doesn’t carry it themselves (heterozygous)

Question 11

What does PCR stand for?

Answer 11

Polymerase chain reaction

Question 12

Purpose of PCR

Answer 12

To make multiple copies of a DNA molecule

Question 13

Denaturing

Answer 13

step one in PCR. Double strands come apart at the base pairs. 90 degrees

Question 14

Annealing

Answer 14

step 2 in PCR. Primers attach to the target sequence 50-60 degrees

Question 15

Extension

Answer 15

step 3 in PCR. DNA Taq Polymerase attaches to primers and copies the target sequence

Question 16

Three uses for PCR

Answer 16

1. Forensic-tissue identification in violent crimes
2. Disease Diagnosis-genetic disease genes can be confirmed
3. Relational-can be used to detect a genetic relationship between individuals

Question 17

What is a clone?

Answer 17

an exact genetic copy of biological matter

Question 18

Molecular cloning

Answer 18

first type of cloning. Copy of a DNA molecule

Question 19

Reproductive (organismal)

Answer 19

cloning the entire organisms

Question 20

Therapeutic

Answer 20

cloning stem cells-for treatment of disease

Question 21

Evolution

Answer 21

change over time

Question 22

Lamarck’s 3 principles (evolutionary theory)

Answer 22

1. Desire to change- all organisms have the desire to better themselves in their environment
2. Use and Disuse- If you use a part then it will get better, If you don’t use it then it won’t work as well
3. Acquired Traits- individuals inherit the traits of their ancestors.

Question 23

Darwin’s 5 steps to evolutionary change:

Answer 23

1. Individuals must vary (differences)
2. More individuals must be born than can possibly survive
3. Competition (struggle for survival)
4. Individuals that are “best adapted” to the environment have a better chance for survival (natural selection)
5. These individuals have a better chance of passing traits to the next generation (offspring) (natural selection)

Question 24

How can environmental pressure cause change in species over time?

Answer 24

the pressure can give an advantage to have a paticular gene-which would cause individuals with it to increase in the population

Question 25

Why can mutations cause variations in a population

Answer 25

mutations in DNA cause variations in traits

Question 26

What is natural selection?

Answer 26

Individuals that are “best adapted” to the environment have a better chance for survival (natural selection) These individuals have a better chance of passing traits to the next generation (offspring) (natural selection)