genetics

Question 1

What is DNA?

Answer 1

DNA (deoxyribonucleic acid) is a blueprint of information used to make an organism

DNA controls activities in cells by providing instructions to make proteins.

Question 2

What structure does DNA form?

Answer 2

DNA forms a structure called a double helix made from subunits called nucleotides.

Question 3

What are the components of a nucleotide?

Answer 3

Nucleotides are made of:
* deoxyribose (a sugar)
* phosphate group
* one of four nitrogenous bases: adenine, guanine, thymine, cytosine.

Question 4

What are the two types of nitrogenous bases in nucleotides?

Answer 4

The two types are:
* Purines (double ring structure): adenine and guanine
* Pyrimidines (single ring structure): cytosine and thymine.

Question 5

What is the significance of the antiparallel structure of DNA strands?

Answer 5

The strands run in opposite directions, allowing for complementary base pairing.

Question 6

What base pairs with adenine in RNA?

Answer 6

Uracil pairs with adenine in RNA.

Question 7

What is transcription?

Answer 7

Transcription is the process of making RNA using DNA.

Question 8

What is the role of ribosomes in translation?

Answer 8

Ribosomes are the sites of translation where mRNA is translated into protein.

Question 9

What are codons?

Answer 9

Codons are mRNA base triplets that specify the amino acid to be placed in a polypeptide.

Question 10

How many codons are there, and how many code for amino acids?

Answer 10

There are 64 codons, of which 61 code for amino acids.

Question 11

What is a point mutation?

Answer 11

A point mutation is a chemical change in just one base pair of a gene.

Question 12

What are the two general categories of point mutations?

Answer 12

The two categories are:
* Base pair substitutions
* Base pair insertions or deletions.

Question 13

What is the function of histone proteins in DNA?

Answer 13

Histone proteins help package DNA into nucleosomes, which condense into chromatin.

Question 14

What is the cell theory?

Answer 14

The cell theory states:
* All living things are composed of one or more cells
* Cells are the smallest units of living organisms
* New cells come only from pre-existing cells by cell division.

Question 15

What are the three main stages of the cell cycle?

Answer 15

The three main stages are:
* Interphase
* Mitosis
* Cytokinesis.

Question 16

What happens during the G1 phase of interphase?

Answer 16

During G1, the cell undergoes major growth and synthesizes new molecules and organelles.

Question 17

What characterizes metaphase in mitosis?

Answer 17

In metaphase, spindle fibers guide chromosomes to the equator of the cell.

Question 18

What occurs during anaphase?

Answer 18

In anaphase, sister chromatids separate and are pulled to opposite poles of the cell.

Question 19

What is cytokinesis?

Answer 19

Cytokinesis is the division of the cytoplasm to create two new daughter cells.

Question 20

What is a karyotype?

Answer 20

A karyotype is an individual set of chromosomes that can be photographed and sorted.

Question 21

What is the difference between haploid and diploid cells?

Answer 21

Haploid cells contain one set of chromosomes (n), while diploid cells contain two sets (2n).

Question 22

What is the result of meiosis?

Answer 22

Meiosis produces gametes with half the number of chromosomes of the parent cell.

Question 23

What is crossing over?

Answer 23

Crossing over is the exchange of segments between homologous chromosomes during prophase I of meiosis.

Question 24

Fill in the blank: The complete DNA sequence in every cell of an organism is called the _______.

Answer 24

genome.

Question 25

True or False: Mutations can lead to the production of an abnormal protein.

Answer 25

True.

Question 26

What is the function of the promoter region in transcription?

Answer 26

The promoter region is where RNA polymerase binds to initiate transcription.

Question 27

What is the role of tRNA in translation?

Answer 27

tRNA carries specific amino acids and has an anticodon that base-pairs with the mRNA codon.

Question 28

What is the process that begins with 6 chromosomes and involves duplication of centrosomes?

Answer 28

Interphase ## Footnote Interphase is the phase before meiosis begins, where the cell prepares for division.

Question 29

During prophase I of meiosis, what happens to the nucleolus and nuclear membrane?

Answer 29

They disintegrate ## Footnote This marks the beginning of chromosome condensation.

Question 30

What is formed during crossing over at chiasma?

Answer 30

Genetic diversity ## Footnote Crossing over allows segments of chromosomes to be exchanged.

Question 31

In metaphase I, where do pairs of homologous chromosomes line up?

Answer 31

Along the equator (metaphase plate) ## Footnote This alignment is crucial for the proper segregation of chromosomes.

Question 32

What law describes that only one chromosome from each homologous pair will be found in each new daughter cell?

Answer 32

Law of segregation ## Footnote It emphasizes the separation of homologous chromosomes during anaphase I.

Question 33

What occurs during telophase I and cytokinesis?

Answer 33

Nuclear membrane re-forms and cleavage furrow splits the cell into 2 haploid cells ## Footnote Each daughter cell contains half the original number of chromosomes.

Question 34

Does meiosis II involve an interphase?

Answer 34

No interphase II ## Footnote There is no duplication of DNA prior to meiosis II.

Question 35

How many daughter cells are produced at the end of meiosis II?

Answer 35

4 haploid daughter cells ## Footnote Each cell contains a single set of chromosomes.

Question 36

What is the primary purpose of mitosis?

Answer 36

Growth, repair, maintenance ## Footnote Mitosis is crucial for cellular duplication and tissue maintenance.

Question 37

What is gametogenesis?

Answer 37

Production of sex cells (gametes) in animals by meiosis ## Footnote It includes processes like spermatogenesis and oogenesis.

Question 38

Where does spermatogenesis occur?

Answer 38

In the testes of males ## Footnote It begins with a diploid cell called the spermatogonium.

Question 39

What is the outcome of oogenesis?

Answer 39

One viable egg and polar bodies ## Footnote The unequal division of cytoplasm results in one functional egg and smaller polar bodies that degenerate.

Question 40

What is deletion in terms of chromosome structure?

Answer 40

A piece of the chromosome is deleted ## Footnote An example is cri du chat syndrome caused by a deletion in chromosome 5.

Question 41

What chromosomal abnormality is associated with Charcot-Marie-Tooth disease?

Answer 41

Duplication ## Footnote This condition is often caused by the duplication of a gene on chromosome 17.

Question 42

What happens during translocation?

Answer 42

A segment of one chromosome becomes attached to a different chromosome ## Footnote This can lead to genetic disorders like chronic myelogenous leukemia.

Question 43

What is aneuploidy?

Answer 43

Having an abnormal number of chromosomes ## Footnote It includes conditions like trisomy and monosomy.

Question 44

What syndrome is associated with trisomy 21?

Answer 44

Down syndrome ## Footnote It is characterized by intellectual disabilities and physical abnormalities.

Question 45

What is the frequency of occurrence for Klinefelter syndrome?

Answer 45

1 in 1000 males ## Footnote It is due to the presence of an extra X chromosome (XXY).

Question 46

What is the outcome of non-disjunction during meiosis?

Answer 46

Gametes with too many or too few chromosomes ## Footnote This can lead to aneuploidy in offspring.

Question 47

Which chromosome abnormalities result in Turner syndrome?

Answer 47

XO (missing one X chromosome) ## Footnote This condition leads to short stature and sexual underdevelopment.