Introduction to Genetics

Question 1

DNA

Answer 1

-double helix (just like a spiral staircase):
backbone/strands (“rails”), includes alternating sugars and phosphates and the said strands are oriented in opposite directions;
(“steps”), pairs of nitrogenous bases - Adenine (A) & Thymine (T) and Cytosine (C) & Guanine (G) (bases are attracted with one another or are pairs)

Question 2

Genome (Human)

Answer 2

-contains about 20,325 protein-encoding genes (Exome) or only about 1.5%;
the rest of it are DNA sequences that aids in protein synthesis or turn on or off protein encoding genes

Question 3

Allele

Answer 3

-gene variants;
Slight variation in DNA base sequence in a protein-encoding gene
- gene variants present in the organism

Question 4

Chromosome

Answer 4

-rod-shaped
-23 pairs are found in Human somatic/non-sex cell:
Autosomes (22 pairs; numbered from 1-22)

Sex chromosomes (1 pair; X and Y)
Female : XX
Male : XY

*In each set of 23 chromosomes, protein-encoding genes are dispersed among 3.2 billion DNA bases

Question 5

Cell

Answer 5

-its utilization (expression) of some of its genes will produce proteins and lead to specific appearance and activities (differentiation/specialization)

Question 6

Examples of Cell

Answer 6

Adipose cell (with fat; nucleus is preserved up to the side of the cell)
Muscle cell (with contractile proteins)

Question 7

Tissue

Answer 7

-group of differentiated cells including their secreted non-living materials
-4 basic types
Epithelial, Connective, Muscle, and Nervous

Question 8

Organ

Answer 8

-made up of tissues that intertwine and layer; connect to form organ system

Question 9

Example of Organ

Answer 9

Example:
Stomach
(includes mainly muscle tissue and epithelial tissue that serves as lining)

Question 10

Stem cells

Answer 10

• rare and unspecialized; found in several organs and allow an organ to grow and repair damage
• divide to generate another stem cell and a cell that differentiates

Question 11

Genotype

Answer 11

• underlying instructions
• alleles present
• carrier of the allele

Question 12

Phenotype

Answer 12

• visible trait, biochemical change, or effect on health

- alleles expressed (what traits/characteristics do you have)

Question 13

Dominant allele

Answer 13

-1 copy on one chromosome

Question 14

Recessive allele

Answer 14

-present on both chromosomes of a pair

Question 15

Individual & Family

Answer 15

-gene variants shared with relatives:
Approximately half (with each parent, sibling, and offspring);
One-quarter (with each grandparent);
One-eighth (first cousins)

Question 16

Gene pool

Answer 16

-all the alleles in a population

Question 17

Example of gene pool

Answer 17

Greater frequency of alleles that specify dark hair and skin in Nigeria

Question 18

Parts of the Individual

Answer 18

1. Genotype
2. Phenotype
3. Dominant allele
4. Recessive allele

Question 19

Heredity

Answer 19

means inheritance and transmission of traits; biological information among generations

Question 20

Variation

Answer 20

differences which can be on structural or maybe physiological characteristics; variation in an individual coming from the same species

Question 21

Process of genetics

Answer 21

1. Genes (the instructions) prompts the cell to produce protein.
2. Proteins controls the characteristics which results in the inherited trait.

Question 22

Protein-coding genes’ function

Answer 22

Can possibly produce protein

Note: Non-coding genes such as DNA has a different function.

Question 23

Genetics

Answer 23

• branch of Biology; focuses on heredity and variation

Question 24

Genes

Answer 24

• basically considered as section/s of the DNA
• basic physical units of heredity
• biochemical instructions that direct the cells how certain proteins are produced

Question 25

Genome

Answer 25

• organism’s complete set of genetic instructions includes protein-encoding genes and other DNA sequences
• 2 copies of which is usually found in a cell

Question 26

Genomics

Answer 26

• deals with analysis and comparison of genomes

- can also look at function, sequences (of genes), assign (of genome itself)

Question 27

Bioethics

Answer 27

• emphasizes medical technology’s moral issues and controversies
• deals with medical technology; not only with agriculture but also with medicine

Question 28

Examples of Bioethics

Answer 28

1. rice fortified with Vitamin A called “Golden Rice” (agricultural)
2. determination of possible genetic diseases starting with newborn (medicines)

Question 29

What are the “opposite directions” orientation called? (in terms of the alternating sugars and phosphates)

Answer 29

Anti-parallel

Question 30

Deoxyribose

Answer 30

• a 5-carbon sugar (pentose)

Question 31

What are the non-coding genes?

Answer 31

DNA sequences

Question 32

Fruitfly - drosophilia

Answer 32

• used before in Genetics experiment

Question 33

Total number of chromosomes

Answer 33

• 46 chromosomes in total

Question 34

23 chromosomes

Answer 34

• one set; happens that there are in pairs so you have 2 sets referring to the genome of the specific organism

Question 35

Genetic expression

Answer 35

• biochemical instruction that directs the cell to produce proteins then, the proteins will produce specific characteristics

Question 36

What does the term “body cell” suggest?

Answer 36

The term body cell suggests that they are the cells that are dominant in the body.

Question 37

What happens during fertilization?

Answer 37

Implication of fertilization to the genome –> once the haploid undergoes fertilization, they will become diploid

Question 38

Why are the stem cells significant?

Answer 38

It allows the body’s development, growth, and repair.