Unit 2: Genetics

Question 1

What is DNA?

Answer 1

• Hereditary material which makes up genes in organisms
• “Biological instructions”
• Double stranded
• Most DNA is located in the cell nucleus + a little in the mitochondria
• Base of ATCG

Question 2

What is RNA?

Answer 2

• Codes for proteins (protein synthesis)
• Single stranded
• Located in the nucleus and cytoplasm

Question 3

What does ADENINE-THYMINE mean?

Answer 3

• In DNA, adenine and thymine pair together (complementary)
• The amt. of adenine in DNA should be equal to the amt. of thymine

Question 4

What does CYTOSINE-GUANINE mean?

Answer 4

• In DNA, the bases of cytosine and guanine pair together
• Amt. of cytosine = guanine

Question 5

What is PHOSPHATE?

Answer 5

Forms part of the backbone of the DNA double helix that provides structural support to the molecule

Question 6

What is RIBOSE?

Answer 6

A sugar that forms the backbone of ribonucleic acid (RNA)

Question 7

What is CHROMOSOME?

Answer 7

A DNA molecule that contains the genetic information for an organism

Question 8

What is CHROMATIN?

Answer 8

A mixture of DNA and proteins that form the chromosomes found in the cells of organisms

Question 9

What is CHROMATID?

Answer 9

• One of the two identical halves of a chromosome that has been replicated in preparation for cell division.
• Two “sister” chromatids are joined at a constricted region of the chromosome called the centromere

Question 10

CHROMOSOME vs CHROMATIN vs CHROMATID

Answer 10

Chromatin condenses into… Chromosome/Chromatid/Sister Chromatids

Question 11

What is DNA REPLICATION?

Answer 11

• The process by which the DNA is copied in cells
• Allows two identical daughter cells to have identical DNA

Question 12

Explain the MITOSIS CELL CYCLE

Answer 12

PMAT (prophase, metaphase, anaphase, telophase) then cytokinesis
*Draw a diagram

Question 13

Explain the STAGES OF MEIOSIS

Answer 13

PMAT (prophase, metaphase, anaphase, telophase) then cytokinesis
*Draw a diagram

Question 14

What is AESEXUAL REPRODUCTION?

Answer 14

• Type of reproduction that does not involve the fusion of gametes or change in the number of chromosomes
• Production of offspring by a single parent

Question 15

What is SEXUAL REPRODUCTION? What is ZYGOTE?

Answer 15

A gamete with a single set of chromosomes combines with another gamete to produce a zygote (fertilized egg) that develops into an organism composed of cells with two sets of chromosomes.

Question 16

What is a GENE?

Answer 16

• Short section of DNA
• Instructions that tell your cells to make molecules called proteins.
• Instructions that determine your features, such as eye colour, hair colour and height.

Question 17

What are HOMOLOGOUS PAIRS?

Answer 17

• a set of one maternal and one paternal chromosome that pair up with each other inside a cell during fertilization.
• pair #1…pair #22 from largest to smallest

Question 18

What are GAMETES?

Answer 18

• Produced in the gonads
• Product of meiosis (which involves germ cells)

MALE: sperm, produced in the testes
FEMALE: “eggs” or ova, produced in the ovaries

Question 19

AUTOSOMAL vs SEX-LINKED

Answer 19

AUTOSOMAL: chromosome(s) 1-22
SEX-LINKED: chromosome(s) 23

Question 20

MATERNAL vs PATERNAL

Answer 20

Two sets of chromosomes in each person, one set of 23 from their mother, another set of 23 from their father
Humans have a total of 46 chromosomes (23 pairs)

Question 21

HOMOZYGOUS vs HETEROZYGOUS

Answer 21

Two copies of a gene is considered homozygous for that trait, different copies of a gene for a particular trait is considered heterozygous for that trait

e.g. AA vs Ab
Homozygous dominant vs heterozygous

Question 22

What are ALLELES?

Answer 22

The alternative form or versions of a gene
e.g. if I were looking at the gene trait for har colour, one might have a BROWN ALLELE or a BLACK ALLELE or a BLOND ALLELE

Question 23

GENOTYPE vs PHENOTYPE

Answer 23

GENOTYPE
An organism’s genetic makeup
e.g. BB, Bb, bb

PHENOTYPE
The observable and expressed physical traits
e.g. Purple, Purple, White

Question 24

What is a TRAIT?

Answer 24

A specific characteristic of an individual

Question 25

RECESSIVE vs DOMINANT

Answer 25

DOMINANT alleles OVERRULE RECESSIVE alleles

Question 26

INCOMPLETE DOMINANCE vs CO-DOMINANCE

Answer 26

Alleles are only partially expressed
RR = red; Rr = pink; rr = white

Alleles are both expressed
RR = red; Rr = red AND white; rr = white

Question 27

What are MULTIPLE ALLELES?

Answer 27

When multiple versions of a gene exist for the same trait (?)

Question 28

Explain the BLOOD TYPES

Answer 28

Type A: iA iA OR iA i
Type B: iB iB OR iB i
Type AB: iA iB
Type O: i i

Question 29

What are POLYGENIC TRAITS?

Answer 29

A characteristic, such as height or skin color, that is influenced by two or more genes

Question 30

What is a PEDIGREE FLOWCHART?

Answer 30

Diagram that uses shading and shapes to represent inheritance of a certain trait throughout generations.

Question 31

What is DOWN SYNDROME?

Answer 31

Genetic disorder caused by a trisomy 21

OTHER GENETIC DISORDERS INCLUDE trisomy or monosomy

Question 32

What do CARBOHYDRATES do?

Answer 32

Form the backbone of DNA and RNA chains

Question 33

What do PROTEINS do?

Answer 33

Proteins serve as structural support, biochemical catalysts, hormones, enzymes, building blocks, and initiators of cellular death.

Question 34

What do LIPIDS do?

Answer 34

Store energy, signal, and act as structural components of cell membranes.

Question 35

What do NUCLEIC ACIDS do/what are they?

Answer 35

Nucleic acids, deoxyribonucleic acid (DNA) and ribonucleic acid (RNA), carry genetic information