Genetic Processes

Question 1

what is genetics

Answer 1

studies how genetic information about traits is passed from generation to generation

Question 2

what is inheritance in sexually reproducing organisms

Answer 2

the inheritance of traits determines genetic variation among offsprings

Question 3

why is genetic variation required

Answer 3

for evolution

Question 4

What makes organisms unique

Answer 4

the order of the nitrogenous bases in DNA

Question 5

structure of DNA

Answer 5

double helix

Question 6

what are chromosomes

Answer 6

• coiled DNA inside the nucleus of a cell

Question 7

what does DNA stand for

Answer 7

deoxyribonucleic acid which are huge molecules

Question 8

what does each chromosome carry

Answer 8

the genetic information for a specific set of traits in genes

Question 9

what is a gene

Answer 9

• a short segment of DNA that controls the expression of a trait
• has instructions to make one protein

Question 10

proteins

Answer 10

• form from all cell structures and enzymes
• many hormones are proteins
• are critical for transporting materials across membranes

Question 11

what are somatic cells

Answer 11

• body cells
• diploid chromosomes

Question 12

how many pairs of chromosomes do humans have

Answer 12

• 23 pairs
• 46 chromosomes

Question 13

what are gametes

Answer 13

• haploid
• a single copy of each chromosome

Question 14

how are sex cells produced

Answer 14

• meiosis

Question 15

what is DNA

Answer 15

• a type of nucleic acid
• a macromolecule containing genetic info
• in eukaryotic cells it is found in the nucleus
• in prokaryotic cells it is found in the cytoplasm

Question 16

what are nucleic acids

Answer 16

polymers

Question 17

what are DNA monomers called

Answer 17

• nucleotides
• many monomers bonded together are called polynucleotide

Question 18

what are nucleotides made of

Answer 18

1. a phosphate group
2. pentose sugar
3. a nitrogenous base

Question 19

what are the two types of pentose sugars

Answer 19

• deoxyribose (missing an O2 atom)
• ribose (has missing O2 atom)

Question 20

how many nitrogenous bases are there and what are they called

Answer 20

• 4 types
• adenine bonds to thymine
• guanine bonds to cytosine

Question 21

what is the phosphodiester bonds

Answer 21

the phosphate group bonded to the pentose sugar

Question 22

what does the phosphodiester bond create

Answer 22

a sugar-phosphate backbone

Question 23

how are polynucleotides read

Answer 23

read from 5’ to 3’

Question 24

DNA polymers

Answer 24

• double stranded
• two strands are antiparallel and complementary

Question 25

what are the two strands held together by

Answer 25

- hydrogen bonds which forms the double helix shape - hydrogen bond holds the two strands together like a zipper

Question 26

what does antiparallel mean

Answer 26

- one strand of the backbone runs from 5' - 3' - second stand runs from 3' - 5'

Question 27

what does complementary mean

Answer 27

- nitrogenous bases on one strand are complementary to bases on the other strand

Question 28

how many bonds does each nitrogenous base form

Answer 28

- adenine forms 2 hydrogen bonds with thymine - guanine forms 3 hydrogen bonds with cytosine

Question 29

How is the double helix formed

Answer 29

- phosphodiester bonds form backbone of the DNA ladder - hydrogen bonds are the rungs of the ladder - when it is twisted it forms the double helix shape

Question 30

how does polynucleotide become chromosome

Answer 30

- DNA double helix coils around proteins called histones to form nucleosomes - DNA is called chromatin at this point - chromatin coils and supercoils to form a chromosome

Question 31

how does one chromosome form

Answer 31

- double helix condenses to form a single chromosome (unduplicated) - chromatid replicates (during S-phase of interphase) to form sister chromatid - still one chromosome but is duplicated - splits during mitosis and one chromatid goes to each daughter cell