Genetics unit terms

Question 1

Function of DNA

Answer 1

carries genetic information of the cell

Question 2

Chromosome structure

Answer 2

a threadlike structure composed of a single dsDNA molecule wrapped around histone proteins structure

Question 3

What is a centromere

Answer 3

attachment site for proteins/ other chromosomes

Question 4

What are sister chromatids

Answer 4

A copied form of the same gene joined together (still count as one chromosome)

Question 5

What are genes?

Answer 5

Short sections of DNA that codes for a functional protein or RNA molecule. Each gene occupies a specific location on a chromosome

Question 6

Locus

Answer 6

location of specific gene

Question 7

Allele

Answer 7

specific part of a gene that is responsible for variation in inherited traits

Question 8

What causes mutations?

Answer 8

mistakes when DNA is replicated, and environmental factors

Question 9

What is the haploid number?

Answer 9

the number of “kinds” of chromosomes (n)

- human haploid number is 23

Question 10

What is the diploid number?

Answer 10

number of chromosomes (2n)

- human diploid number is 46

Question 11

What is ploidy?

Answer 11

The number of copies of each type of chromosome

Question 12

What is a homologous chromosome or homolog?

Answer 12

Chromosomes that have:

• the same genes (in the same position/locus); same or different alleles-same size*
• same shape*
• same centromere position*

Question 13

What is a genotype?

Answer 13

Specific alleles of a particular set of genes being studied

Question 14

What is heterozygous?

Answer 14

2 different alleles for the same gene

Question 15

What is homozygous?

Answer 15

2 copies of the same alleles for the same gene

Question 16

2 important concepts of cell theory

Answer 16

1. All organisms are made of cells

2. All cells come from pre-existing cells

Question 17

What four things must occur before cell division can take place?

Answer 17

1. The cell must grow (so daughter cells are normal in size)
2. Synthesize cytoplasm and organelles (so daughter cells can function)
3. Copy the DNA (for each daughter cell)Nuclear division can then begin.
4. The cell must also ensure that each daughter cell inherits a nucleus containing undamaged chromosomes of the appropriate ploidy.

Question 18

What are the four phases of the cell cycle?

Answer 18

G1 —>S —>G2 —>M

Question 19

When do the three checkpoints of the cell cycle occur?

Answer 19

1. before S phase (during G1)
2. before M phase (during G2)
3. during M phase

Question 20

What three phases occur during interphase?

Answer 20

G1, S, G2

Question 21

Autosome

Answer 21

any chromosome that is not a sex chromosome, each copy has same structure.

Question 22

unreplicated chromosome

Answer 22

a chromosome that consists of one double helical molecule of DNA packaged with proteins for compactness

Question 23

replicated chromosome

Answer 23

Chromosome after DNA replication consists of 2 identical chromatids, each containing one double-helical DNA packaged with proteins for compactness

Question 24

Sister chromatids

Answer 24

2 identical chromatid copies in a replicated chromosome